Download Initial Assessment - Benthic Habitats

Benthic Habitats
1.1
Introduction
This report aims at fulfilling the requirements of the EU Marine Strategy Framework
Directive in describing the biological communities associated with predominant
seabed habitats and assessing their status based on data existing to date. For the
purposes of this report, data generated by marine surveys, including surveys
commissioned in relation to the implementation of EU policies, and data originating
from environmental assessment procedures was extracted and collated from the
data repository of the Malta Environment and Planning Authority (MEPA). Efforts
were made to supplement this data by scientific data from the published literature in
an attempt to provide a complete overview of current knowledge on benthic
habitats to the extent possible.
Overall, the majority of the existing data pertains to inshore waters, with only
sporadic data available for deeper offshore habitats. The uneven data distribution on
marine habitats is attributed to the fact that ecological surveys in Malta throughout
the past years focused on depths which could be reached by SCUBA diving and/or
inshore areas subject to coastal developments. Deeper waters have only recently
started being scientifically investigated1. This data scenario precludes the possibility
to assess all MSFD predominant benthic habitats at the same level of detail.
Furthermore, current data limitations and gaps present significant difficulties in
applying the MSFD criteria and indicators2 for assessment of status.
The predominant habitat types to be described and assessed for the purposes of the
MSFD are established by the Commission Staff Working Paper3. Depth zones with
which the predominant habitat types are associated are specified in Table 1.
Determination of these depth zones was based on the scientific literature, namely
the RAC/SPA habitat classification4 and Howell (2010)5. The lower bathyal and the
abyssal zones will not be considered any further in this report in view of data
limitations.
1
2
3
4
5
Borg, J.A; Howege, H.M.; Lanfranco, E; Micallef, S.; Mifsud, C. & Schembri, P.J. 1998. The Macrobenthic
species of the infralittoral to circalittoral transition zone off the North-eastern coast of Malta (Central
Mediterranean). Xjenza 3 (1); 16-24
Commission Decision of 1 September 2010 on criteria and methodological standards on good environmental
status of marine waters (2010/477/EU)
Commission Staff Working Paper: Relationship between the initial assessment of marine waters and the
criteria for good environmental status. SEC(2011)1255 final
Established through the Protocol for Specially Protected Areas and Biodiversity in the Mediterranean
(SPABIM), primarily based on the Peres & Picard scheme (1967) defining seven vertical marine zones
Howell (2010) in https://webgate.ec.europa.eu/maritimeforum/system/files/all_annexes.pdf
1
Table 1: Comparison of the marine zones associated with the MSFD Habitat Classification,
the Peres & Picard scheme (1967) and their respective depth.
MSFD habitat
classification
Littoral
Shallow sublittoral
Shelf sublittoral
Upper Bathyal
Lower Bathyal
Peres & Picard
scheme (1967)
Mediolittoral
Infralittoral
Circalittoral
Bathyal
Abyssal
Abyssal
Depth
0m
0m – 50m6
50m – 200m
200m and 1100m8
1,100m – 2,700m9
below 3000 m
Topography
Coastal Waters
Continental Shelf7
Continental slope
Abyssal plain
Table 2 provides an indication of the benthic habitats which would fit into each of
the MSFD predominant habitat type category as stipulated by the Commission Staff
Working Paper. The content of this table is based on an exercise carried out by Borg
& Schembri (2002)10, through which local marine habitats data was aligned with
habitat types as listed in the EU Habitats Directive (92/43/EEC) and the RAC/SPA
habitat classification11. This exercise focused on the inshore or coastal areas thus
covering the littoral, shallow sublittoral and partly the shelf sublittoral MSFD habitat
types. Marine habitat types representing the shelf and bathyal habitat types were
extrapolated from the EUNIS classification of habitats.
This report, which was compiled by MEPA in consultation with Professor P.J.
Schembri and Dr. J.A. Borg, experts in the field of marine biology, provides a brief
description of the benthic habitats within each MSFD predominant habitat type
category, an indication of the pressures exerted on such habitats by anthropogenic
activities and an assessment of status, where possible. Although the present report
provides a general description of the habitat types at a National scale, assessment
areas, which would vary for different habitat types, were defined for the purposes of
assessment of status. The information provided in this report is based on existing
data, hence the different levels of detail provided for the different habitat types.
6
7
8
9
10
11
The boundary between the shallow sublittoral and shelf sublittoral MSFD habitat types was set at 50m, based
on the vertical extent of occurrence of marine phanerograms, namely Posidonia oceanica in Malta. In the
Maltese Islands, the maximum depth at which stands of this species have been recorded is 44m (Borg J. A.,
Micallef M. A, & Schembri P. J., 2006. Spatio-temporal variation in the structure of a deep water Posidonia
oceanica meadow assessed using non-destructive techniques. Marine Ecology 27: 320 - 327.)
Definition of continental shelf by the Continental Shelf Act: "the continental shelf" means the sea bed and
subsoil of the submarine areas adjacent to the coast of Malta but outside territorial waters, to a depth of two
hundred metres or, beyond that limit, to where the depth of the superjacent waters admits of the
exploitation of the natural resources of the said areas…
Howell (2010) in https://webgate.ec.europa.eu/maritimeforum/system/files/all_annexes.pdf
ditto
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Established through the Protocol for Specially Protected Areas and Biodiversity in the Mediterranean
(SPABIM)
2
Table 2: Habitat types considered for the purposes of the MSFD based on Borg & Schembri (2002) and the EUNIS classification of habitats.
MSFD classification
of habitats12
EUNIS code
Subcomponents based on the RACSPA habitat types13 and Borg &
Schembri (2002)14
Biocoenosis of the upper mediolittoral rock
(II.4.1)
Littoral rock and
biogenic reef
A1: Littoral Rock and
other hard substrata
Biocoenosis of the lower mediolittoral rock
(II.4.2)
Mediolittoral caves (II.4.3)
Biocoenosis of muddy sands and muds (II.1.1)
Biocoenosis of mediolittoral sands (II.2.1)
Littoral sediment
A2: Littoral Sediment
Biocoenosis of mediolittoral coarse detritic
bottoms (II.3.1)
Shallow sublittoral rock
and biogenic reef
12
13
14
A3: Infralittoral rock
and other hard
substrata
Biocoenosis of infralittoral algae (III.6.1)
Relevant EUNIS codes for sub-components
A1.13: Mediterranean and Black Sea Communities of upper
mediolittoral rock
A1.14: Mediterranean and Black Sea Communities of Lower
Mediolittoral rock very exposed to wave action
A1.23: Mediterranean Communities of lower mediolittoral rock
moderately exposed to wave action
A1.34: Mediterranean Communities of lower mediolittoral rock
sheltered from wave action
A1.44: Communities of littoral caves and overhangs
A2.5: Coastal saltmarshes and saline reedbeds
A2.2: Littoral Sand and muddy sand
A2.25: Mediterranean and Pontic Communities of mediolittoral
sands
A2.1: Littoral coarse sediments
A2.13: Mediterranean communities of mediolittoral coarse
detritic bottoms
A3.1:
A3.13: Mediterranean and Pontic communities of infralittoral
algae very exposed to wave action
A3.14: Encrusting algal communities
A3.15: Frondose
algal
communities
(otherfor
than
kelp)
MSFD Habitat Classification as defined by the Commission Staff Working Paper: Relationship between the initial assessment
of marine
waters
and the criteria
good
environmental
A3.23: Mediterranean and Pontic communities of infralittoral algae
status [SEC(2011)1255 final]
Established through the Protocol for Specially Protected Areas and Biodiversity in the Mediterranean (SPABIM)
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the requirements of the EU habitats directive (Council Directive 92/43/EEC).
[Report Commissioned by the Malta Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
3
MSFD classification
of habitats12
EUNIS code
Subcomponents based on the RACSPA habitat types13 and Borg &
Schembri (2002)14
Relevant EUNIS codes for sub-components
moderately exposed to wave action;
A3.33: Mediterranean submerged fucoids, green or red seaweeds on
full salinity infralittoral rock;
A4.26: Mediterranean coralligenous communities moderately
exposed to hydrodynamic action
A5.5: Macrophyte
dominated sediment
(?)
Shallow sublittoral
coarse sediment
A5: Sublittoral
sediment
[A5.1 sublittoral coarse
sediments]
Posidonia oceanica meadows (III.5)
Biocoenosis of infralittoral coarse sands and
fine gravels mixed by waves (III.3.1)
Biocoenosis of infralittoral stones and
pebbles (III.4.1)
Biocoenosis of infralittoral gravels
Biocoenosis of fine sands in very shallow
waters (III.2.1)
Biocoenosis of well sorted fine sands (III.2.2)
Shallow sublittoral sand
A5: Sublittoral
sediment
Biocoenosis of superficial muddy sands in
sheltered waters (III.2.3)
Posidonia oceanica meadows (III.5)
Shallow sublittoral mud
A5: Sublittoral
sediment
Biocoenosis of polluted harbour mud and
sandy mud
4
A5.5: Sublittoral macrophyte-dominated sediment
A5.53: Sublittoral seagrass beds
A5.1: Sublittoral coarse sediments
A5.13: Infralittoral coarse sediment
A5.1: Sublittoral coarse sediments
A5.13: Infralittoral coarse sediment
A5.1: Sublittoral coarse sediments
A5.13: Infralittoral coarse sediment
A5.2: Sublittoral Sand
A5.23: Infralittoral fine sand
A5.5: Sublittoral macrophyte-dominated sediment
A5.53: Sublittoral seagrass beds
A5.2: Sublittoral Sand
A5.28: Mediterranean communities of superficial muddy sands
in sheltered waters
A5.5: Sublittoral macrophyte-dominated sediment
A5.53: Sublittoral seagrass beds
A5.5: Sublittoral macrophyte-dominated sediment
A5.53: Sublittoral seagrass beds
A5.3: Sublittoral mud
A5.5: Sublittoral macrophyte-dominated sediment
MSFD classification
of habitats12
EUNIS code
Subcomponents based on the RACSPA habitat types13 and Borg &
Schembri (2002)14
Relevant EUNIS codes for sub-components
A5.53: Sublittoral seagrass beds
[& A5.5: Sublittoral
macrophyte-dominated
sediment]
Shallow sublittoral mixed
sediment
Shelf sublittoral rock and
biogenic reef
Shelf sublittoral coarse
sediment
Shelf sublittoral sand
A5: Sublittoral
sediment
A4: Circalittoral rock
and other hard
substrata
A5: Sublittoral
sediment
A5: Sublittoral
sediment
Sandy muds, sands, gravels and rocks in
euryhaline and eurythermal environment
(III.1)
Biocoenosis of infralittoral coarse sands and
muddy heterogenous sediments
Circalittoral Coralligenous biocoenosis (IV.3.1)
Circalittoral Semi-dark caves (IV.3.2)
Biocoenosis of shelf-edge rock (IV.3.3)
Biocoenosis of coarse sands and fine gravels
under the influence of bottom currents
(maerl facies and association with rhodoliths)
(III.3.2)
Biocoenosis of circalittoral coarse sands and
fine gravels under the influence of bottom
currents (IV.2.4).
A5.5: Sublittoral macrophyte-dominated sediment
A5.52: Kelp and seaweed communities on sublittoral sediment.
A5 including A5.53 Sublittoral seagrass beds
A4.2: Atlantic and Mediterranean circalittoral rock
A4.26: Mediterranean coralligenous communities moderately
exposed to hydrodynamic action;
A4.3: Atlantic and Mediterranean low energy circalittoral rock
A4.32: Mediterranean coralligenous communities sheltered from
hydrodynamic action
A4.33: Faunal communities on deep low energy circalittoral rock;
A4.7: Features of circalittoral rock
A4.71: Communities of circalittoral caves and overhangs
A4.2 Atlantic and Mediterranean circalittoral rock
A5.5: Sublittoral macrophyte-dominated sediment
A5.51: Maerl beds
A5.14: Circalittoral coarse sediment
A5.2: Sublittoral sand
A5.25: Circalittoral fine sand
A5.26: Circalittoral muddy sediments
Circalittoral Sands (IV.2)
5
MSFD classification
of habitats12
EUNIS code
Shelf sublittoral mud
A5: Sublittoral
sediment
Shelf sublittoral mixed
sediment
A5: Sublittoral
sediment
Upper bathyal rock and
biogenic reef
A6: Deep seabed
Upper bathyal sediment
A6: Deep seabed
Subcomponents based on the RACSPA habitat types13 and Borg &
Schembri (2002)14
Biocoenosis of coastal terrigenous muds
(IV.1.1)
Biocoenosis of the muddy detritic bottom
(IV.2.1)
Biocoenosis of the circalittoral coastal detritic
bottom (IV.2.2)
Biocoenosis of shelf-edge detritic bottom
(IV.2.3)
Biocoenosis of deep sea corals (V.3.1)
Caves and ducts in total darkness (V.3.2)
Deep-sea bioherms
Biocoenosis of bathyal muds (V.1.1)
Biocoenosis of bathyal detritic sands with
Grypheus vitreus (V.2.1)
Biocoenosis of bathyal detritic sands with
Grypheus vitreus (V.2.1)
6
Relevant EUNIS codes for sub-components
A5.3: Sublittoral Mud
A5.39: Mediterranean commuities of coastal terrigenous muds
A5.3: Sublittoral Mud
A5.38: Mediterranean communities of muddy detritic bottoms
A5.39: Mediterranean commuities of coastal terrigenous muds
A5.4: Sublittoral mixed sediment
A5.46: Mediterranean animal communities of coastal detritic
bottoms
A5.51: Maerl beds
A5.52: Kelp and seaweed communities on sublittoral sediment
A5.47: Mediterranean communities of shelf-edge detritic bottoms
A6.61: Communities of deep-sea corals
A4.71: Communities of circalittoral caves and overhangs
A6.62: Deep-sea sponge aggregations
A6.51: Mediterranean communities of bathyal muds
A6.31: Communities of bathyal detritic sands with Grypheus vitreus
A6.31: Communities of bathyal detritic sands with Grypheus vitreus
1.2
Relevant Legislation and Management Activities
The marine environment is governed by various policies at local, regional and
international level calling for the conservation of marine habitats and species
or the management of marine activities which may impact on marine habitats
and species. Most of these policies are to some extent or other linked to the
implementation of the Marine Strategy Framework Directive. This section
briefly outlines the main legislative tools which are relevant to the
conservation of marine benthic habitats.
Table 3 lists the policies which are deemed relevant for the purposes of MSFD
implementation. Table 4 outlines the relations between the benthic habitats
listed under the various policies and the MSFD predominant habitat types as
identified by the Commission Staff Working Paper.
1.2.1 EU legislation
EU Nature Directives and the EU Biodiversity Strategy to 2020
The EU Nature Directives comprise the Habitats Directive (92/43/EEC) and
the Birds Directive (2009/147/EC), which are locally transposed to national
law through the Flora, Fauna and Natural Habitats Protection Regulations,
2006 (Legal Notice 311 of 2006 as amended) and the Conservation of Wild Birds
Regulations, 2006 (Legal Notice 79 of 2006 as amended). These regulations
provide for the designation of protected areas in the marine environment.
Designated protected areas falling within the criteria of the Nature Directives
form part of the EU Natura 2000 network of protected areas, which is aimed
at maintaining or restoring natural habitats and species listed in the Directive
at a Favourable Conservation Status. The Directives also call for the strict
protection of species, particularly all native wild birds (including seabirds) and
species listed in Annex IV of the EU Habitats Directive.
The goals of the EU Habitats Directive in restoring or maintaining listed
marine habitats and species at a Favourable Conservation Status are in line
with those of the Marine Strategy Framework Directive in achieving Good
Environmental Status in marine waters. The EU MSFD widens this scope to
cover habitat types other than those listed in the annexes to the Habitats
Directive.
The EU Biodiversity Strategy 2020 calls for the fulfilment of the Habitats
Directive with a view to halt the deterioration in the status of all species and
habitats covered by EU nature legislation and achieve a significant and
measurable improvement in their status so that by 2020, 100% more habitat
assessments occur and 50% more species assessments under the Habitats
Directive show an improved conservation status.
7
Water Framework Directive (2000/60/EC)
The EU Water Framework Directive (WFD) 2000/60/EC focuses on the
protection of all water resources, including coastal waters. For the purposes
of the WFD, the coastal waters around the Maltese Islands have been divided
into 9 distinct water bodies, the boundaries of which were determined on the
basis of the predominant physical and ecological characteristics, as well as on
the nature and magnitude of pressures on the coastal water environment.
Two of the nine water bodies designated around the Maltese Islands, namely
the harbour areas (Il-Port il-Kbir and Il-Port ta’ Marsamxett; Il-Port ta’
Marsaxlokk) are Heavily Modified Water Bodies15.
The main objective of the WFD for coastal water bodies is the achievement,
by 2015, of ‘good ecological status’ up to one nautical mile from the coast;
‘good chemical status’ for all territorial waters (12 nautical miles) and ‘good
ecological potential’16 for heavily modified water bodies. ‘Good ecological
status’ is defined by the ecological status of biological elements, including
elements associated with benthic habitats such as seagrasses, macroalgae
and benthic invertebrates. Achievement of such good status would
contribute to the achievement of Good Environmental Status for benthic
habitats within the framework of the MSFD.
Malta’s Water Catchment Management Plan17 identifies a series of measures
aimed at achieving the goals of the WFD for the identified water bodies.
Through this plan, Malta is also requesting exemptions to achieving good
status for three coastal water bodies18.
1.2.2 Regional Conventions and/or International Agreements
Convention on Biological Diversity
The Convention on Biological Diversity (CBD) is a major UNEP-driven
multilateral environment agreement targeted at the conservation of
biological diversity, the sustainable use of its components, and the fair and
equitable sharing of the benefits arising from the utilisation of genetic
resources. The CBD also calls for the identification of ecologically or
biologically significant areas (EBSAs) in marine areas beyond national
15
16
17
18
Heavily Modified Water Bodies are substantially changed in character as a result of physical alterations by
human activity, and cannot therefore, meet ‘good ecological status’
‘Good Ecological Potential’ is less stringent objective than good ecological status , making allowances for
ecological impacts resulting from alterations to the physical environment that are necessary to either support
a specific use, or must be maintained in order to avoid effects on the wider environment.
http://www.mepa.org.mt/topic-wcmp
http://www.mepa.org.mt/topic-wcmp
8
jurisdiction, based on scientific criteria as contained in Annex I to CBD
Decision IX/20.
In October 2010, the Conference of Parties of the CBD adopted a revised and
updated strategic plan for biodiversity, which includes the ‘Aichi Biodiversity
Targets’ aimed at achieving the objectives of the Convention. These targets
have been taken on board by the Malta’s National Biodiversity Strategy and
Action Plan19.
The Convention on the Conservation of European Wildlife and Natural
Habitats (Bern Convention)
The Council of Europe’s Bern Convention aims at the conservation of
European wild flora and fauna and their natural habitats, with a particular
focus on the protection of endangered natural habitats and endangered
species. The natural habitat types requiring specific conservation measures
are listed in Resolution No. 4 (1996) adopted by the Standing Committee of
the Convention on 6 December 1996. In 2010, this list was revised in line with
the EUNIS Habitat Classification.
The provisions of the Bern Convention are addressed through the Flora,
Fauna and Natural Habitats Protection Regulations, 2006 (Legal Notice 311 of
2006 as amended), which is the National legal instrument transposing the
requirements of the EU Habitats Directive and various biodiversity-related
multilateral environment agreements.
The Convention for the Protection of the Mediterranean Sea against Pollution
(Barcelona Convention)
The Barcelona Convention led to a protocol concerning Mediterranean
Specially Protected Areas in 1982, which was amended and renamed the
Protocol for Specially Protected Areas and Biodiversity in the Mediterranean
(SPABIM) in 1995. Parties to this protocol are obliged to establish protected
areas and to undertake all actions necessary in order to protect these areas
and, as appropriate, to restore them as rapidly as possible. The protocol lists
habitat types for the selection of sites to be included in National inventories
of Natural Sites of Conservation Interest, which list was finalised by the 4th
meeting of the National Focal Points for SAP and cleared by the meeting of
MAP focal points on the 6 September 1999 in Athens.
The provisions of this protocol are addressed through the Flora, Fauna and
Natural Habitats Protection Regulations, 2006 (Legal Notice 311 of 2006 as
amended), which is the National legal instrument transposing the
19
http://www.cbd.int/nbsap/about/latest
9
requirements of the EU Habitats Directive and various biodiversity-related
multilateral environment agreements. .
Table 3: List of regional and EU policies relevant to MSFD implementation with respect to
benthic habitats
Policies relevant to marine benthic habitats
Convention on Biological Diversity
Convention on the Conservation of European
Wildlife and Natural Habitats (Bern Convention)
Protocol for Specially Protected Areas and
Biological Diversity in the Mediterranean of the
Barcelona Convention
Council Directive 92/43/EEC of 21 May 1992 on
the conservation of natural habitats and of wild
fauna and flora (Habitats Directive)
The Convention on Wetlands (Ramsar
Convention)
Directive 2000/60/EC of the European
Parliament and of the Council establishing a
framework for the Community action in the field
of water policy (Water Framework Directive)
Council Regulation 1967 of 2006 concerning
management measures for the sustainable
exploitation of fishery resources in the
Mediterranean Sea
10
Equivalent legislation at National
scale
Convention on Biological Diversity
Incorporation Regulations, 2002 (Legal
Notice 160 of 2002)
Flora, Fauna and Natural Habitats
Protection Regulations, 2006 (Legal
Notice 311 of 2006 as amended)
Conservation of Wild Birds Regulations,
2006 (Legal Notice 79 of 2006 as
amended)
Malta’s National Biodiversity Strategy
and Action Plan
Water Policy Framework Regulations,
2004 (Legal Notice 194 of 2004)
Directly Applicable
Table 4: Listed marine habitat types as per EU Habitats Directive, Barcelona Convention and the Bern Convention within each MSFD habitat category.
MSFD Habitat
Classification
Annex I habitat types – Habitats
Directive
Habitat types for the selection of sites to be
included in the National Inventories of
Natural Sites of Conservation Interest – as
finalised by the 4th meeting of the National
Focal Points for SPA (Tunis, 12-14 April 1999)
Habitat types listed as endangered
natural habitat types requiring
specific conservation measures
under the Bern Convention (Emerald
Network) in accordance with
Resolution No. 4 (1996) – make a
note of the mixture of using EUNIS
and Emerald Network codes
Littoral rock and biogenic
reef
Reefs (1170)
Association with Lithophyllum lichenoides (II.4.2.1)
Submerged or partially submerged sea
caves (8330)
Coastal lagoons (1150)
Neogoniolithon brassica-florida concretion
(II.4.2.8)
Pools and lagoons sometimes associated with
vermetids (II.4.2.10)
Association with Phymatolithon lenormandii and
Hildenbrandia rubra (II.4.3.1)
Association with halophytes (II.1.1.1)
Association with [Lithophyllum byssoides]
– (A1.141)
Moderate energy littoral rock (A1.2)
Littoral sediment
Communities of littoral caves and
overhangs (A1.44)
Coastal saltmarshes and saline reedbeds
(A2.5)
Facies of banks of dead leaves of Posidonia
oceanica and other phanerograms
Littoral Sand and muddy sand (A2.2)
Shallow sublittoral rock and
biogenic reef
Reefs (1170)
Submerged or partially submerged sea
caves (8330)
Association with Cystoseira amentacea (III.6.1.2)
Facies with vermetids (III.6.1.3)
Facies with Cladocora caespitosa (III.6.1.14)
Association with Cystoseira brachycarpa
(III.6.1.15)
Association with Cystoseira crinita (III.6.1.16)
Association with Cystoseira crinitophylla
(III.6.1.17)
11
Association with Cystoseira spinosa (III.6.1.19)
Association with Sargassum vulgare (III.6.1.20)
Facies and associations of coralligenous
biocoenosis (III.6.1.35)
Shallow sublittoral coarse
sediment
Shallow sublittoral sand
Posidonia beds (1120)
Sandbanks which are slightly covered by
seawater all the time (1110)
Sublittoral soft seabeds (11.22)
Seagrass meadows (11.3)
Sandbanks which are slightly covered by
seawater all the time (1110)
Posidonia beds (1120)
Association with Halophila stipulacea (III.2.2.2)
Ecomorphosis of ‘barrier reef’ meadows
Facies with Loripes lacteus and Tapes spp.
(III.2.3.3)
Shallow sublittoral mud
Sublittoral soft seabeds (11.22)
Sublittoral soft seabeds (11.22)
Shallow sublittoral mixed
sediment
Shelf sublittoral rock and
biogenic reef
Mediterranean coralligenous
communities moderately exposed to
hydrodynamic action (A4.26)
Seagrass meadows (11.3)
Seagrass meadows (11.3)
Reefs (1170)
Submerged or partially submerged sea
caves (8330)
Association with Ruppia cirrhosa and/or Ruppia
elongata (III.1.1.1)
Association with Halopitys elongata (III.1.1.8)
Association with Cystoseira zosteroides (IV.3.1.1)
Association with Cystoseira usneoides (IV.3.1.2)
Association with Cystoseira dubia (IV.3.1.3)
Association with Cystoseira corniculata (IV.3.1.4)
Association with Sargassum sp. (IV.3.1.5)
Association with Laminaria ochroleuca (IV.3.1.8);
Association with Rodriguezella strafforelli
(IV.3.1.9);
Facies with Eunicella cavolinii (IV.3.1.10);
Facies with Eunicella singularis (IV.3.1.11);
Facies with Lophogoria sarmentosa (IV.3.1.12);
12
Sublittoral soft seabeds (11.22)
Mediterranean coralligenous
communities moderately exposed to
hydrodynamic action (A4.26);
Mediterranean coralligenous
communities sheltered from
hydrodynamic action (A4.32)
Mediterranean coralligenous
communities moderately exposed to
hydrodynamic action (A4.26)
Mediterranean coralligenous
Facies with Paramuricea clavata (IV.3.1.13);
Coralligenous platforms (IV.3.1.15)
Facies with Corallium rubrum (IV.3.2.2)
Shelf sublittoral coarse
sediment
Association with rhodoliths (III.3.1.1)
Maerl facies (= Association with Lithothamnion
corallioides and Phymatolithon calcareum)
(III.3.2.1)
Association with rhodoliths (III.3.2.2)
communities sheltered from
hydrodynamic action (A4.32)
Mediterranean coralligenous
communities moderately exposed to
hydrodynamic action (A4.26)
Communities of circalittoral caves and
overhangs (A4.71)
Sublittoral soft seabeds (11.22)
Shelf sublittoral sand
Sublittoral soft seabeds (11.22)
Shelf sublittoral mud
Sublittoral soft seabeds (11.22)
Shelf sublittoral mixed
sediment
Upper bathyal rock and
biogenic reef
Reefs (1170)
Upper bathyal sediment
Reefs (1170)
Association with Laminaria rodriguezii on detritic
(IV.2.2.7)
Facies with large Bryozoa (IV.2.2.10)
Biocoenosis of deep sea corals (V.3.1)
Caves and ducts in total darkness (V.3.2)
Facies of soft muds with Funiculina
quadrangularis and Apporhais seressianus
(V.1.1.3)
Facies of compact muds with Isidella elongata
(V.1.1.4)
13
Sublittoral soft seabeds (11.22)
Communities of circalittoral caves and
overhangs (A4.71)
1.2.3 Other policies
Council Regulation (EC) No 1967/2006 concerning management measures for the
sustainable exploitation of fishery resources in the Mediterranean Sea, relates to the
conservation, management and exploitation of living aquatic resources in the
Mediterranean.
This regulation constitutes a number of provisions related to the conservation of
marine resources including the regulation or prohibition of specific fishing activities
on protected or sensitive habitats, in particular Posidonia oceanica, coralligenous
habitats, maerl beds and corals. The regulation also calls for the establishment of
Fishing Protected Areas in which fishing activities may be banned or restricted in
order to conserve and manage living aquatic resources or maintain or improve the
conservation status of marine ecosystems; and for the adoption of management
plans for specific Mediterranean fisheries.
The regulation adopts the 25-mile Fisheries Management Zone around the Maltese
Islands and stipulates provisions regulating fishing within this zone.
1.2.4 Protected areas
Malta has designated five Special Areas of Conservation in the marine environment
within the framework of the Habitats Directive (92/43/EEC), published as per
Government Notice 851 of 2010 (Figure 1). The designation of these Marine
Protected Areas was mainly based on the presence of Posidonia oceanica meadows
as a priority habitat type of the Habitats Directive.
14
Figure 1: Marine Special Areas of Conservation in Malta
15
1.3
Benthic habitats Characteristics
1.3.1 Littoral Rock and Biogenic Reef
According to published information, rocky shores make up circa 90% of the Maltese
coastline20, with gently sloping shores prevailing along the North-eastern coastline of
the islands and sheer vertical cliffs characterising the Southwestern coast.
The gently sloping shores support macroalgal communities occupying the lower
mediolittoral zone, generally characterised by belts of Cystoseira species in well-lit
places and Corallina elongata in shaded places. Platforms formed by the alga
Neogoniolithon brassica-florida and the vermetid Dendropoma petraeum are also
reported to be common on such shores21.
The sheer vertical cliffs represent a favourable substratum for biogenic concretions
such as those of Lithophyllum byssoides. They also support a number of mediolittoral
caves formed by the direct action of the sea on the limestone rock at sea level. These
caves are generally characterised by three distinct zones, the extent of which would
depend on physiographic conditions22:
an outer zone where some light penetrates allowing the growth of photophilic
algae at the opening with progressively more sciaphilic species further inwards
from the mouth;
a middle section dominated by sessile invertebrates (sponges, corals, tubicolous
polychaetes, bryozoans, hydroids, brachiopods and foraminifera) with few algae,
almost all encrusting corallines;
a completely dark inner section largely devoid of sessile organisms.
The macroalgal communities along the mediolittoral zone were studied at a National
scale through a 2008 survey23 aimed at the application of the CARLIT24 methodology
for the determination of ecological status of the Maltese littoral rock. This
methodology is being currently applied to evaluate the quality of coastal waters as
part of the monitoring programme of the Water Framework Directive, the official
20
21
22
23
24
Gauci, M.; Deidun, A. & Schembri, P.J. 2005. Faunistic diversity of Maltese pocket sandy and shingle beaches:
are these of conservation value? Oceanologia 47 (2) pp. 219 – 241.
Schembri, P.J. (1995): Threatened habitats as a criterion for selecting coastal protected areas in the Maltese
Islands. Rapport du Congres de la Commission Internationale pour l’Exploration Scientifique de la Mer
Mediterranee 34: 128
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Thibaut, T. 2011. Ecological Status of the Rocky Coast of Malta, May 2008
Cartography of littoral and upper-sublittoral benthic communities as an approach to use macroalgae as a key
biological quality element for the assessment of the ecological status in coastal waters in the frame of the
European Water Framework Directive – Ballesteros, E.; Torras, X; Pinedo, S.; Garcia, M.; Mangialajo, L. &
deTorres, M. 2007. A new methodology based on littoral community cartography dominated by macroalgae
for the implementation of the European Water Framework Directive. Marine Pollution Bulletin 55: 172-180.
16
results of which will be available by June 201325. The distribution of algal
communities, Lithophyllum byssoides trottoirs and caves on the lower mediolittoral
as mapped through the 2008 CARLIT survey is shown in Figure 2 and
25
CIBM & Ambiente SC. 2012. Development of Environmental Monitoring Strategy and Environmental
Monitoring Baseline Surveys – Water Lot 3 – Surveys of Coastal Water – August 2012. ERDF156 - Developing
national environmental monitoring infrastructure and capacity
17
Figure 3. The CARLIT data on caves was supplemented by published information on
this habitat type26.
Both the 2008 and 2012 surveys confirm that Cystoseira amentacea var. stricta is the
most abundant species for this habitat type, accompanied by other Cystoseira
species including C. crinita, C. compressa and C. brachycarpa. Cystoseira amentacea
var. stricta occupies, albeit at varying densities, about 57% (>112km over 195km
mapped coastline) of the total Maltese rocky shores. The distribution pattern of the
algal communities dominated by C. amentacea var. stricta is shown in Figure 4.
When Cystoseira beds are absent, gently sloping coastlines are characterised by
assemblages dominated by other algal species including Laurencia sp., Dictyota sp
and Dictyopteris polypodioides27. In disturbed areas Cystoseira species are generally
replaced by calcareous alga such as Corallina elongata and Enteromorpha (=Ulva)
species, both of which, where they occur at high densities in the absence of
Cystoseira species, can be considered to be indicators of reduced water quality,
particularly due to the presence of nitrate and phosphate pollution28. Such degraded
zones are mainly located in ports and inner parts of bays subject to anthropogenic
disturbance (J.A. Borg & P.J. Schembri, personal communication). A stretch of
coastline along the North-eastern coast of Malta, which until recently was subject to
discharge of untreated sewage, is also devoid of Cystoseira belts. The sewage outfall
has been replaced by treated sewage effluent in 2012, however it is too early to
detect any changes in algal communities as a result of such replacement.
26
27
28
Wood, L.. & Wood, L.. 1999: The Dive Sites of Malta, Comino & Gozo. Comprehensive Coverage of Diving and
Snorkelling: Progress Press, 111pp.; Aquilina, S. 1995: Treasures of the Maltese Waters. Part One. Shore Dives:
Aquilina Enterprises Ltd, 63pp.; Lemon, P.G. (ND): Scuba Diving Malta, Gozo, Comino: MGP Books Group,
224pp.; Middleton, N. (1997): Maltese Islands Diving Guide: Miller Distributors Ltd, 167pp.
CIBM & Ambiente SC. 2012. Development of Environmental Monitoring Strategy and Environmental
Monitoring Baseline Surveys – Water Lot 3 – Surveys of Coastal Water – August 2012. ERDF156 - Developing
national environmental monitoring infrastructure and capacity
Thibaut, T. 2011. Ecological Status of the Rocky Coast of Malta, May 2008
18
Figure 2: Distribution of habitats associated with Littoral Rock on the Maltese Islands
(Source: Thibaut, 2011)29
29
Thibaut, T. 2011. Ecological Status of the Rocky Coast of Malta, May 2008
19
Figure 3: Indication of the location of mediolittoral caves based on the surveys carried out
by Thibaut, 201130 and other published information31
30
31
Thibaut, T. 2011. Ecological Status of the Rocky Coast of Malta, May 2008
Wood, L.. & Wood, L.. 1999: The Dive Sites of Malta, Comino & Gozo. Comprehensive Coverage of Diving and
Snorkelling: Progress Press, 111pp.; Aquilina, S. 1995: Treasures of the Maltese Waters. Part One. Shore Dives:
Aquilina Enterprises Ltd, 63pp.; Lemon, P.G. (ND): Scuba Diving Malta, Gozo, Comino: MGP Books Group,
224pp.; Middleton, N. (1997): Maltese Islands Diving Guide: Miller Distributors Ltd, 167pp.
20
Figure 4: Distribution pattern in terms of density of Cystoseira amentacea var. stricta as
reported by Thibaut (2011)32
Pressures
Degradation in water quality is considered to be the major threat to Cystoseira
communities on lower mediolittoral rock. Thibaut (2011)33 attributes changes in
biological communities on littoral rock to reduced water quality, specifically to
nutrient enrichment. Nutrient enrichment in Malta is mainly associated with sewage
outfalls and overflows, port operations and agricultural runoff (J.A. Borg & P.J.
Schembri, personal communication). Within this context, it should be noted that all
municipal wastewater is now being treated and second class treated wastewater is
currently being discharged from wastewater treatment plants.
Cystoseira communities are also negatively affected by increase in turbidity of
coastal waters as a result of anthropogenic activities such as dredging, boating and
port operations, as well as a result of run-off.
Coastal development resulting in replacement of rocky shoreline with artificial
coastline, does not generally lead to physical loss of algal communities along the
mediolittoral zone, since such algae can equally colonise natural rock and artificial
substrata (J.A. Borg & P.J. Schembri, personal communication). Nevertheless,
replacement of a gently sloping rocky shore with a vertical artificial coastline, would
reduce the surface area available for colonisation and change light conditions,
32
33
Thibaut, T. 2011. Ecological Status of the Rocky Coast of Malta, May 2008
Thibaut, T. 2011. Ecological Status of the Rocky Coast of Malta, May 2008
21
potentially resulting in narrower algal belts along the shoreline and in changes in the
composition of algal communities. A study carried out as part of the Interreg IIIC
DEDUCE project34 indicated that between the period 1994 and 2004 there was an
increase of 1% in artificial coastline. Development along the coast of the Maltese
Islands is mostly related to harbour, recreation or road development infrastructure,
rather than to coastal defence structures.
Other impacts on littoral rock communities may arise from discharges of brine water
from desalination plants and of cooling waters from power plants. Such discharges
may create localised changes in salinity regimes, potentially leading to changes in
species composition of macroalgae on the lower mediolittoral. Nevertheless such
impacts are highly localised and are deemed to be of low significance. The same
applies to the potential disturbance along the coastline caused by the laying down of
submarine cables and pipelines. Such disturbance is deemed to be both localised and
temporary, since macroalgae are likely to recolonise the disturbed areas.
SCUBA diving is the main source of pressures on the submerged portion of emergent
sea caves and underwater caves. Diving may cause both mechanical damage to erect
sessile forms growing in caves, and death of the biota on the ceiling due to trapped
air bubbles from diving cylinders35. In the protected Qawra/Dwejra area, frequent
visits in caves by SCUBA divers are known to have resulted in destruction of fragile
bryozoan colonies growing on the roof of the caves36. Boating activities may also
have an impact on the biota of the emerged portions of littoral caves (P.J. Schembri,
personal communication).
34
35
36
http://www.deduce.eu/
Schembri, P.J. (1995): Threatened habitats as a criterion for selecting coastal protected areas in the Maltese
Islands. Rapport du Congres de la Commission Internationale pour l’Exploration Scientifique de la Mer
Mediterranee 34: 128
Borg J. A., Micallef S. A., Pirotta K., Schembri P. J., 1997. Baseline marine benthic surveys in the Maltese
Islands (Central Mediterranean). In E. Ozhan (ed.) Proceedings of the third international conference on the
Mediterranean coastal environment, MEDCOAST ë97, November 11-14, 1997, pp 1-8 + v figs.
22
1.3.2 Littoral Sediment
The MSFD ‘Littoral Sediment’ habitat type includes sandy and shingle beaches along
the shoreline; boulder shores are considered as ‘littoral rock’. Sandy (particle size
0.063-2mm), shingle (particle size 2-256mm) or mixed sand and shingle shores are
restricted to small pockets along the Maltese coast occupying circa 2.4% of the
Maltese coastline or an estimate of 6.5km37. In general, circa 6km of the coastline is
sandy, while c. 0.6km is shingle38.
Figure 5 indicates the distribution of sandy and shingle beaches on the Maltese
coastline. Most of the minor beaches included in this figure are highly susceptible to
natural factors, such as storms, and their extent would vary seasonally, with some
beaches completely disappearing from the littoral zone during the winter months
(P.J. Schembri & J.A. Borg, personal communication).
The ecology of sandy and shingle beaches is not well known in Malta, however they
are generally characterised by an impoverished species richness and abundance39. To
date, the poor biodiversity associated with sandy or shingle beaches can neither be
attributed to natural factors nor to anthropogenic disturbance. Nonetheless, in view
of their restricted distribution, sandy or shingle beaches create habitats of high
conservation value supporting rare species. Furthermore, each beach is considered
to be ecologically isolated, especially to species with limited dispersal powers, hence
each beach is associated with unique assemblages of species40,41. To date, such
differences in faunal species across beaches cannot be explained in terms of
different abiotic factors and further studies are deemed necessary42.
A study carried out on eight sandy beaches on mainland Malta and two on Gozo
resulted in the collection of only 16 species from mediolittoral and uppermost
infralittoral zones43. A comparative study on sandy and shingle beaches indicated
that while species richness and abundance were generally low on both shore types,
these parameters were higher on the wet zones of shingle beaches when compared
to same zones on sandy beaches44. Overall, species associated with sandy and
37
38
39
40
41
42
43
44
Gauci, M.; Deidun, A. & Schembri, P.J. 2005. Faunistic diversity of Maltese pocket sandy and shingle beaches:
are these of conservation value? Oceanologia 47 (2) pp. 219 – 241.
ditto
Deidun, A. Azzopardi, M., Saliba, S. & Schembri, P.J. 2003. Low faunal diversity on Maltese sandy beaches:
fact or artefact? Estuarine, Coastal and Shelf Science 58S: 83-92
Deidun, A. Azzopardi, M., Saliba, S. & Schembri, P.J. 2003. Low faunal diversity on Maltese sandy beaches:
fact or artefact? Estuarine, Coastal and Shelf Science 58S: 83-92
Gauci, M.; Deidun, A. & Schembri, P.J. 2005. Faunistic diversity of Maltese pocket sandy and shingle beaches:
are these of conservation value? Oceanologia 47 (2) pp. 219 – 241.
Deidun, A. Azzopardi, M., Saliba, S. & Schembri, P.J. 2003. Low faunal diversity on Maltese sandy beaches:
fact or artefact? Estuarine, Coastal and Shelf Science 58S: 83-92
ditto
Gauci, M.; Deidun, A. & Schembri, P.J. 2005. Faunistic diversity of Maltese pocket sandy and shingle beaches:
are these of conservation value? Oceanologia 47 (2) pp. 219 – 241.
23
shingle beaches are considered to be among the most endangered of the local
biota45.
Species which are generally associated with the wet zones on sandy beaches, and are
thus of relevance to the MSFD, include the polychaete Ophelia bicornis, the isopods
Tylos europaeus occurring only on sandy beaches, Tylos ponticus occurring on gravel,
pebble and cobble, and talitrid amphipods46 (J.A. Borg & P.J. Schembri, personal
communication). Until 2003, O. bicornis was solely recorded from the sandy beach at
Ir-Ramla in Gozo and T. europaeus from White Tower Bay on mainland Malta47.
However research efforts on sandy or shingle beaches undertaken to date are not
deemed adequate enough to provide a clear picture of the actual distribution of
these species on Maltese beaches, also in view of the rarity of such species. In fact,
experts can now confirm the presence of these species on other beaches (J.A. Borg &
P.J. Schembri, personal communication). There are unpublished records of O.
bicornis at Ir-Ramla tal-Mixquqa and T. europaeus has also been recorded at San Blas
in Gozo48. However data on the abundance or biomass of such species is limited to a
few specialised studies, hence the status of such species cannot be determined.
Both sandy and shingle beaches receive substantial inputs of seagrass wrack, mainly
Posidonia, during the autumn and winter months. Posidonia banquettes constitute a
specific habitat type associated with the littoral shoreline, including rocky coastline,
and are considered to be an important source of organic matter on Maltese
beaches49. A quantitative assessment of Posidonia wrack beached along Maltese
coastline provided an estimate of 112.8 metric tons (dry weight) of standing wrack
per km of beach50,51 with a maximum total dry mass of wrack beached along Maltese
coastlines at any one time estimated at ca 1,150 metric tons52. Given the transient
nature of Posidonia banquettes which is easily affected by natural factors, including
storms, they will not be considered any further for the purposes of MSFD assessment
of environmental status.
Other habitat types falling within the scope of the MSFD habitat type ‘Littoral
Sediment’ include saltmarshes (as per EUNIS Habitat type A2.5), or coastal lagoons
as interpreted by the EU Habitats Directive (habitat code 1150)53. This habitat type is
restricted to a few pockets on the Maltese Islands, most of which have been
45
46
47
48
49
50
51
52
53
Deidun, A. Azzopardi, M., Saliba, S. & Schembri, P.J. 2003. Low faunal diversity on Maltese sandy beaches:
fact or artefact? Estuarine, Coastal and Shelf Science 58S: 83-92
Talitrids refer to two species: Talorchestia deshaysii and Talitrus saltator. Distinguishing between these two
species proves difficult hence the use of the term Talitrids incorporating both.
Deidun, A. Azzopardi, M., Saliba, S. & Schembri, P.J. 2003. Low faunal diversity on Maltese sandy beaches:
fact or artefact? Estuarine, Coastal and Shelf Science 58S: 83-92
Deidun, A.; Galea Bonavia, F. & Schembri, P.J. 2011. Distribution of Tylos spp. in the Maltese Islands and
th
population dynamics of Tylos europaeus. Journal of Coastal Research, SI 57 (Proceedings of the 11
International Coastal Symposium), 369 – 372. Szczecin, Poland, ISBN
Gauci, M.; Deidun, A. & Schembri, P.J. 2005. Faunistic diversity of Maltese pocket sandy and shingle beaches:
are these of conservation value? Oceanologia 47 (2) pp. 219 – 241.
Deidun, A.; Saliba, S. & Schembri, P.J. 2011. Quantitative assessment and physical characterisation of
Posidonia oceanica wrack beached along the Maltese coastline. Biol.Mar. Mediterr., 18 (1): 307-308
3
A mean mass of 27.3 kg ± 2.4 kg for 1 m of air-dried wrack and a mean banquette depth of 0.5 m were used
for the calculation;
Deidun, A.; Saliba, S. & Schembri, P.J. 2011. Quantitative assessment and physical characterisation of
Posidonia oceanica wrack beached along the Maltese coastline. Biol.Mar. Mediterr., 18 (1): 307-308
European Commission, DG Environment. 2007. Interpretation Manual of European Union Habitats
24
significantly engineered or altered by anthropogenic interference or disturbance54.
While the connection of these sites to the marine environment has been retained55
through culverts (Il-Ballut, Marsaxlokk), pipelines (Il-Magħluq, Marsaskala) or
through natural seepage of the adjacent seawater, such connection is largely
artificial. In this regard, this type of habitat is not being considered further for the
purposes of the MSFD. Nevertheless, all extant coastal lagoons are included in
Special Areas of Conservation as designated within the framework of the Habitats
Directive and will thus be managed and conserved for the purposes of this Directive.
Further information regarding range, area and status of this habitat type can be
found at:
http://cdr.eionet.europa.eu/mt/eu/art17/envrflrpw/habitattype1150.xml/manage_document,
http://cdr.eionet.europa.eu/mt/eu/n2000;
http://www.mepa.org.mt/impnatareas-pas-int-n2k-dsmap
Figure 5: Location of sandy and shingle beaches representing Littoral Sediment for the
Maltese Islands (Source: MEPA)
54
55
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
In line with the document entitled ‘Links between the Marine Strategy Framework Directive (MSFD
2008/56/EC) and the Nature Directives (Birds Directive 2009/147/EEC (BD) and Habitats Directive 92/43/EEC
(HD)’, coastal lagoons should only be considered under marine reporting if there is a permanent connection
with the sea.
25
Pressures
Beaches on the Maltese Islands constitute an important recreational resource. Due
to the fact that they are restricted to small pockets along the shore, most beaches
are subject to intense recreational use particularly during the summer season.
Such recreational activities constitute the major threat to this habitat type and
associated species. In view of the uniqueness of each beach in terms of species and
the unclear relationships between species composition and abiotic factors, it is
difficult to attribute difference in species composition to anthropogenic or natural
factors. On the other hand, undisturbed beaches are generally associated with the
highest number of sand-specific species, implying that human disturbance influences
the macrofaunal species composition of a beach56. The extent of the effect of
anthropogenic disturbance on beach ecology is nevertheless unknown.
In view of their recreational use, beaches are regularly cleaned. Although the degree
of impact of such activity is largely dependent on the mechanisms used, it is
considered to be a potential source of disturbance to the beach fauna. Furthermore,
the removal of Posidonia banquettes from beaches may expose such beaches to
erosion processes and potentially lead to a reduction in organic matter on the
beaches. Deidun et al. (2007)57 suggest that thick banquettes on ‘ungroomed58’
beaches contribute more to beach biodiversity and to carbon cycling, while values of
wrack percent organic matter content were estimated to be higher for ‘ungroomed’
beaches59. The significance of such difference in organic matter however is not
known.
The main pressure on the extent of beaches along the Maltese coastline arises from
interferences with processes related to sand accretion and erosion, as a result of
development on the coastline as well as development on land. Development on the
coastline, such as the construction of jetties, would result in changes in the
hydrodynamic regime of coastal waters which in turn may lead to erosion of sandy
beaches. Development on land on the other hand would reduce the sediment supply
from terrestrial valley systems. Both types of development have resulted in a
reduction in the extent of a number of sandy beaches. Furthermore, these effects
take place gradually over a long period of time and effects of past developments are
still being observed to date and are expected to continue in the future. Given the
already limited extent of Maltese pocket beaches, any reduction in their extent is
deemed to be significant. While beach replenishment projects may have the
opposite effect, hence an increase in the extent of beaches, such projects would
56
57
58
59
Deidun, A. & Schembri, P.J. 2008. Long or short? Investigating the effect of beach length and other
environmental parameters on macrofaunal assemblages of Maltese pocket beaches. Estuarine, Coastal and
Shelf Science. 79: 17-23
Deidun, A.; Saliba, S. & Schembri, P.J. 2007. Banquette faunal assemblages from groomed and ungroomed
beaches on the Maltese Islands. Rapp. Comm. Int. Mer Medit., 38: pp.456
Beaches which are not regularly cleaned
Deidun, A.; Saliba, S. & Schembri, P.J. 2011. Quantitative assessment and physical characterisation of
Posidonia oceanica wrack beached along the Maltese coastline. Biol. Mar. Mediterr. 18 (1): 307 – 308.
26
generally have a negative effect on the beach biota (J.A. Borg & P.J. Schembri,
personal communication).
1.3.3 Shallow sublittoral rock and biogenic reef
Communities of infralittoral algae, together with Posidonia oceanica meadows on
rock are considered to be the most important communities in terms of cover on
shallow rocky bottoms from 0-30m depth60. Posidonia oceanica meadows will be
described in further detail with the ‘shallow sublittoral sediment’. Figure 6 depicts
the distribution of communities associated with shallow sublittoral rock based on
available data. Such data constitutes snapshot data and does not cover the whole
extent of this substrate type in Malta61. However, an indication of the presence of
rocky substrata in shallow waters is provided in Figure 7, which data is extracted
from the results of a side-scan sonar survey carried out in 200262. Given the current
data limitations, only a generic description of this habitat type as extracted from
published literature is possible at this stage.
A general description of the different biotopes associated with sublittoral rock is
given by Pirotta et al. (1997)63 as follows:
Sublittoral rock characterised by sloping bedrock extending for a considerable
distance out to sea: such slopes can be further subdivided into gentle and steep
slopes dominated by photophilic macroalgae, mainly phaeophytes in shallow
waters with chlorophytes becoming more important with increasing depth.
Underwater cliff faces or drop-offs which can be continuous vertical slopes or
stepped with ledges and breaks across their face: the biota of drop-offs depends
on the topography of the substratum but generally consists of photophilic
macroalgae overlying a sciaphilic assemblage of encrusting sponges, corals,
hydroids and bryozoans. Sciaphilic assemblages dominate in low light conditions
either beneath ledges or in rock crevices64.
Boulder fields which are characterised by detached fragments of rock >50cm in
diameter over an extensive slope: this type of seabed is very heterogeneous and
is characterized by continuously changing depth and light intensity depending on
the arrangement of the individual boulders. The biota of boulder fields consists
of assemblages dominated by photophilic macroalgae in high light intensity and
60
61
62
63
64
Borg J. A., Micallef S. A., Pirotta K., Schembri P. J., 1997. Baseline marine benthic surveys in the Maltese
Islands (Central Mediterranean). In E. Ozhan (ed.) Proceedings of the third international conference on the
Mediterranean coastal environment, MEDCOAST ë97, November 11-14, 1997, pp 1-8 + v figs.
The distribution map was created through an amalgamation of the current snapshot data. Overlapping data
was addressed through selection of the most recent and/or higher resolution data.
G.A.S. [Geological Assistance & Services] 2003. Baseline survey of the extent and character of Posidonia
oceanica (L.) Delile meadows in the territorial waters of the Maltese Islands. Final Report. Geological
Assistance & Services s.r.l. (G.A.S.) Bologna, Italy, iii + 176pp
Pirotta, K. & Schembri, P.J. 1997. Characterisation of the Major Marine Biotopes occurring around the
Maltese Islands: Biotopes of Hard Substrata. In: E. Ozhan (ed). Proceedings of the third international
conference on the Mediterranean coastal environment, MEDCOAST 97, November 11-14
Pirotta, K. & Schembri, P.J. 1997. Characterisation of the Major Marine Biotopes occurring around the
Maltese Islands: Biotopes of Hard Substrata. In: E. Ozhan (ed). Proceedings of the third international
conference on the Mediterranean coastal environment, MEDCOAST 97, November 11-14
27
by sciaphilic assemblages consisting mainly of encrusting species in low light
conditions65.
Due to the tilting of the Maltese Islands to the Northeast, the North-eastern coast is
characterised by gently sloping rocky seabed mainly exploited by communities of
photophilic algae and in some areas by P. oceanica meadows settled on rock66. Most
of the Southwestern coast of the Maltese Islands is on the other hand characterised
by cliffs and boulder fields occurring at the base of the vertical faces, supporting
extensive communities of macroalgae. Since relatively large depths are generally
reached within small horizontal distances (5-200m) from the shoreline, these
communities of photophilic algae consist mainly of sciaphilic assemblages. Seagrass
meadows are rarely encountered in these sites67.
Algal communities characterising infralittoral rock include those dominated by the
phaeophytes Cystoseira species in shallower waters, including Cystoseira amentacea
var. stricta which assemblage has also been described for the lower mediolittoral
zone. Other Cystoseira species characterising the infralittoral of Malta include C.
brachycarpa, C. spinosa, C. compressa and C. ercegovicii68.
Other algal species which when in dominance constitute specific benthic associations
include the phaeophytes Sargassum vulgare, Dictyopteris polypodioides, Halopteris
scoparia, Padina pavonica and Zonaria tourneforti; the chlorophytes Dasycladus
vermicularis, Flabellia petiolata, Cladophora prolifera, Acetabularia acetabulum and
Caulerpa racemosa; and the rhodophytes Peyssonnelia squamaria and Halopithys
pinastroides69.
Some assemblages occur in polluted areas particularly ports and harbours such as
the association with Dictyota dichotoma and Halimeda tuna, the association with
Cladophora prolifera and the association with Corallina elongata and Amphiroa sp.70.
The same applies to the alga Enteromorpha (=Ulva) linza which colonises the
mediolittoral and upper infralittoral zone in polluted waters and may be an indicator
of nutrient enrichment71.
65
66
67
68
69
70
71
Pirotta, K. & Schembri, P.J. 1997. Characterisation of the Major Marine Biotopes occurring around the
Maltese Islands: Biotopes of Hard Substrata. In: E. Ozhan (ed). Proceedings of the third international
conference on the Mediterranean coastal environment, MEDCOAST 97, November 11-14
Borg J. A., Micallef S. A., Pirotta K., Schembri P. J., 1997. Baseline marine benthic surveys in the Maltese
Islands (Central Mediterranean). In E. Ozhan (ed.) Proceedings of the third international conference on the
Mediterranean coastal environment, MEDCOAST ë97, November 11-14, 1997, pp 1-8 + v figs.
Borg J. A., Micallef S. A., Pirotta K., Schembri P. J., 1997. Baseline marine benthic surveys in the Maltese
Islands (Central Mediterranean). In E. Ozhan (ed.) Proceedings of the third international conference on the
Mediterranean coastal environment, MEDCOAST ë97, November 11-14, 1997, pp 1-8 + v figs.
Borg, J.A. & Schembri, P.J., 2002 Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
ditto
ditto
Galdies, C. & Borg, J.A. 2006. Aerial Remote Sensing and Spatial Analysis of Marine Benthic Habitats in St
George’s Bay (Malta); 2nd International Conference on the Management of Coastal Recreational Resources
Beaches, Yacht Marinas and Coastal Ecotourism; Gozo, Malta; 81-87.
28
Faunal species characteristic of infralittoral rock include72:
the sponge Chondrilla nucula associated with well-lit conditions,
Astroides calycularis common in shady conditions,
Dendropoma/Neogoniolithon trottoirs occurring at sea level and the
uppermost reaches of the infralittoral,
Serpulorbis arenaria occurring on exposed rock in shallow water.
Cladocora caespitosa which forms small colonies not more than 15cm in
diameter. No reefs (or continuous cover of colonies) are formed however73,74.
Localised surveys describe communities on shallow sublittoral rock which may
represent enclaves of deeper water communities. These communities were recorded
within shallow caves and on shaded vertical rock faces at relatively shallow depths
not exceeding 42m75,76. This habitat type is characterised by encrusting algae
(including Peyssonnelia squamaria recorded in the Filfla area and Lithophyllum
frondosum in association with Zonaria tournefortii recorded at the mouth of caves in
the Dwejra area), encrusting and erect bryozoans (including Myriapora truncata,
Caberea boryi, Smittina cervicornis and possibly Celleporina caminata and
Schizoporella species), corals (Leptosammia pruvoti), several species of sponges
(including Agelas oroides, Petrosia ficiformis, Faciospongia cavernosa, Buskea
dichotoma and Chondrosia reniformis), the ascidian (Halocynthia papillosa) and
hydroids of the genus Eudendrium sp. With the exception of Peyssonnelia squamaria,
species mentioned above are considered to be characteristic of ‘coralligene’ or
coralligenous communities (vide Ballesteros 2006)77. Some vagile fauna recorded is
also considered to be associated with coralligenous communities such as
Centrostephanus longispinus and Ophidiaster ophidianus. More detailed studies
would be required to determine whether the species assemblages constitute
enclaves of coralligenous communities in shallow waters or otherwise. However,
they almost certainly constitute ‘pre-coralligene’ communities, which differ from
coralligenous communities in terms of extent of concretion by coralline algae and
other encrusting biota, and the cover of the latter (Schembri, P.J., personal
communication)
72
73
74
75
76
77
Borg, J.A. & Schembri, P.J., 2002 Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Borg, J.A. & Schembri, P.J., 2002 Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Schembri, P.J. (1995): Threatened habitats as a criterion for selecting coastal protected areas in the Maltese
Islands. Rapport du Congres de la Commission Internationale pour l’Exploration Scientifique de la Mer
Mediterranee 34: 128
Borg, J.A.; Dimech, M. & Schembri, P.J. 2004. Report on a survey of the marine infralittoral benthic habitats in
the Dwejra/Qawra area (Gozo, Maltese Islands) made in August – September 2004. Survey commissioned by
Nature Trust and the Malta Environment and Planning Authority
AIS Environmental Ltd. & Malta Environment and Planning Authority. 2006. Marine Scientific Surveys around
Filfla for its conservation. Acoustic and Video Report, September 2006. Structural Funds Programme Malta
2004 – 2006.
Ballesteros, E. 2006. Mediterranean Coralligenous Assemblages: A synthesis of present knowledge.
Oceanography and Marine Biology: An Annual Review, 2006, 44, 123-195
29
Figure 6: Distribution of Shallow Sublittoral Rock in Malta (Sources: Borg & Schembri,
200278, Borg et al., 200479, Borg et al. 200980; ADI Associates & Scott Wilson, 200881)
78
79
80
81
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Borg, J.A.; Dimech, M. & Schembri, P.J. 2004. Report on a survey of the marine infralittoral benthic habitats in
the Dwejra/Qawra area (Gozo, Maltese Islands) made in August – September 2004. Survey commissioned by
Nature Trust and the Malta Environment and Planning Authority
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. and Jones, M.B. 2009 Occurrence and distribution of
different bed types of seagrass Posidonia oceanica around the Maltese Islands; Mediterranean Marine
Science 10(2); 45-61
ADI Associates & Scott Wilson. 2008. Detailed investigation and feasibility studies on Land Reclamation at two
indicated search areas, Malta. Technical Report 1; Volume 1. Report prepared for Malta Environment and
Planning Authority.
30
Figure 7: Indication of rocky substrata as identified through the 2002 side-scan sonar
(Source: G.A.S. 200382).
Pressures
Nutrient enrichment is considered to be one of the major pressures on shallow
sublittoral rock communities (J.A. Borg & P.J. Schembri, personal communication).
This pressure is generally associated with sewage outfalls and overflows, port
operations and agricultural runoff.
Other pressures related to human activities in coastal waters, such as boating, could
also be of significance to this habitat type83. Temporary marinas, fisheries berthing
areas and boating activities in general are associated with a chronic input of
contaminants in coastal waters, thus leading to a reduction in water quality.
However, the extent of such pressures on shallow sublittoral rock is unknown. On
the other hand, vulnerable communities which occur on shallow sublittoral rock such
82
83
G.A.S. [Geological Assistance & Services] 2003. Baseline survey of the extent and character of Posidonia
oceanica (L.) Delile meadows in the territorial waters of the Maltese Islands. Final Report. Geological
Assistance & Services s.r.l. (G.A.S.) Bologna, Italy, iii + 176pp
Borg J. A., Micallef S. A., Pirotta K.. & Schembri P. J., 1997. Baseline marine benthic surveys in the Maltese
Islands (Central Mediterranean). In E. Ozhan (ed.) Proceedings of the third international conference on the
Mediterranean coastal environment, MEDCOAST ë97, November 11-14, 1997, pp 1-8 + v figs.
31
as Cladocora caespitosa colonies are threatened by mechanical damage from the use
of heavy anchors and fishing gear84.
Land-based discharges, such as brine discharges from desalination plants and cooling
waters from power plants, and aquaculture (particularly when fish cages are located
very close to shore) may also lead to reduced water quality with associated impacts
on benthic communities characterising shallow sublittoral rock. Nevertheless, such
pressures and associated impacts are considered to be localised.
84
Schembri, P.J. (1995): Threatened habitats as a criterion for selecting coastal protected areas in the Maltese
Islands. Rapport du Congres de la Commission Internationale pour l’Exploration Scientifique de la Mer
Mediterranee 34: 128
32
1.3.4 Shallow sublittoral sediment
Posidonia oceanica meadows
Benthic communities associated with shallow sublittoral sediment in Malta are those
of bare well-sorted sands and seagrass meadows. In terms of cover, Posidonia
oceanica meadows constitute the most important seagrass meadows that exploit
shallow sandy substrata, and to a lesser extent, hard bottoms (Figure 8). P. oceanica
meadows can also be characterised by a high matte composed of sediment and
densely packed rhizomes which may reach a height of several metres85.
Seagrass beds can also be dominated by Cymodocea nodosa, however current data
on the distribution of this assemblage is limited and would not reflect the actual
range and extent of the habitat. In general, Cymodocea nodosa occurs throughout
the infralittoral at depths less than 1m down to about 45-48m and are best
developed on muddy sand bottoms86. The Lessepsian immigrant Halophila stipulacea
may also occur on fine sands, generally in association with C. nodosa up to a depth of
32m. However this is locally rare.
P. oceanica meadows and assemblages associated with Cymodocea nodosa are listed
in Annex I of the Habitats Directive (habitat codes 1120 and 1110 respectively)87. In
general all seagrass assemblages are considered to be important marine habitats in
view of their high productivity. Posidonia meadows in particular provide a highly
heterogeneous species-rich habitat which is associated with a wide range of
ecosystem services through the provision of physical refuge and food for a number
of marine biota, support to commercial fisheries through their role as nurseries as
well as protection of the shore from wave action and coastal erosion88,89.
In 2002, MEPA commissioned a survey to determine the extent of P. oceanica
meadows in Malta90. The results of this side-scan sonar survey are used as the major
source of information on P. oceanica meadows and as baseline data. However it
85
86
87
88
89
90
Pirotta, K. & Schembri, P.J. 1997. Characterisation of the Major Marine Biotopes occurring around the
Maltese Islands: Biotopes of Soft Substrata. In: E. Ozhan (ed). Proceedings of the third international
conference on the Mediterranean coastal environment, MEDCOAST 97, Nov. 11-14
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
http://cdr.eionet.europa.eu/mt/eu/art17/envrflrpw/habitattype-1110.xml/manage_document;
http://cdr.eionet.europa.eu/mt/eu/art17/envrflrpw/habitattype-1120.xml/manage_document.
Borg, J.A. (1998) Habitat Characteristics and fauna of Posidonia oceanica meadows in the Maltese Islands in
Dandria, D (ed) Biology Symposium Biological Abstracts MSc, PhD and contributions to Marine Biology;
Department of Biology, University of Malta.
Schembri, P.J. (1995): Threatened habitats as a criterion for selecting coastal protected areas in the Maltese
Islands. Rapport du Congres de la Commission Internationale pour l’Exploration Scientifique de la Mer
Mediterranee 34: 128
G.A.S. [Geological Assistance & Services] 2003. Baseline survey of the extent and character of Posidonia
oceanica (L.) Delile meadows in the territorial waters of the Maltese Islands. Final Report. Geological
Assistance & Services s.r.l. (G.A.S.) Bologna, Italy, iii + 176pp
33
should be noted that while it provides a general indication of the distribution of
these meadows in Malta, there are inaccuracies, which any quantitative estimates
based on this survey should acknowledge. Of particular note is the limited
recognition by the side-scan sonar of P. oceanica meadows growing on rock, which
thus could be more extensive than indicated by this survey (J.A. Borg & P.J.
Schembri, personal communication). Such inaccuracies were confirmed by Borg et al.
(2009)91, who noted discrepancies between the GAS/MEPA data and the map of the
large-scale distribution of P. oceanica meadows based on distribution data collected
from various studies. For the purposes of this report, the data of the side-scan sonar
was supplemented by either published data92 or by data generated through localised
surveys93.
Posidonia oceanica meadows are concentrated along the North-eastern coast of the
Maltese Islands, covering a length of coastline of about 40.5km with a break of about
5.4km across the harbour areas. Along the Southwestern coast, P. oceanica oceanica
covers about 12.8km of the coastline94. The range and area of P. oceanica meadows
as reported in 2007 as part of the requirements of the Habitats Directive, are 172km2
and 168km2 respectively95.
Within this coverage, the distributional pattern of P. oceanica meadows varies from
continuous meadows to reticulate or patchy meadows with intermittent patches of
sand or rock96. However, the species richness, abundance and assemblage
composition of macroinvertebrates does not seem to differ significantly between
non-fragmented and fragmented beds of Posidonia oceanica97. The general
distribution pattern of this habitat type as extrapolated from four locations studied
by Borg et al. (2009)98 is:
patchy in shallow waters (2-4m) mainly occurring on bedrock,
reticulate beds consisting of P. oceanica growing on a soft sediment bottom
and interspersed with bare sand in deeper waters (5-10m),
continuous beds up to a depth of 25-30m and
91
92
93
94
95
96
97
98
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. and Jones, M.B. 2009 Occurrence and distribution of
different bed types of seagrass Posidonia oceanica around the Maltese Islands; Mediterranean Marine
Science 10(2); 45-61
ditto
High resolution data generated by localised surveys was superimposed on the side-scan sonar data. In areas
of overlap, the side-scan sonar data was replaced by the higher resolution data.
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. and Jones, M.B. 2009 Occurrence and distribution of
different bed types of seagrass Posidonia oceanica around the Maltese Islands; Mediterranean Marine
Science 10(2); 45-61
Calculations are based on a grid-based approach as per European Topic Centre on Biological Diversity (2011)
Assessment and reporting under Article 17 of the Habitats Directive: Explanatory notes & Guidelines for the
period 2007-2012. Final Draft.
Pirotta, K. & Schembri, P.J. 1997. Characterisation of the Major Marine Biotopes occurring around the
Maltese Islands: Biotopes of Soft Substrata. In: E. Ozhan (ed). Proceedings of the third international
conference on the Mediterranean coastal environment, MEDCOAST 97, Nov. 11-14
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. & Jones, M.B. 2010. Spatial variation in the composition
of motile macroinvertebrate assemblages associated with two bed types of the seagrass Posidonia oceanica.
Marine Ecology Progress Series 406: 91–104.
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. and Jones, M.B. 2009 Occurrence and distribution of
different bed types of seagrass Posidonia oceanica around the Maltese Islands; Mediterranean Marine
Science 10(2); 45-61
34
reticulate again in deeper waters.
Posidonia oceanica meadows occur up to a maximum depth of 44m, a depth at
which this type of assemblage is only rarely recorded in Mediterranean waters99.
Figure 8: Distribution of Posidonia oceanica meadows in Malta (Sources: Borg & Schembri, 2002100, Borg
et al. 2004101, G.A.S. 2003102; ADI Associates & Scott Wilson, 2008103; Micallef et al. 2013104)
99
100
101
102
103
104
Borg, J.A. (1998) Habitat Characteristics and fauna of Posidonia oceanica meadows in the Maltese Islands in
Dandria, D (ed) Biology Symposium Biological Abstracts MSc, PhD and contributions to Marine Biology;
Department of Biology, University of Malta.
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Borg, J.A.; Dimech, M. & Schembri, P.J. 2004. Report on a survey of the marine infralittoral benthic habitats in
the Dwejra/Qawra area (Gozo, Maltese Islands) made in August – September 2004. Survey commissioned by
Nature Trust and the Malta Environment and Planning Authority
G.A.S. [Geological Assistance & Services] 2003. Baseline survey of the extent and character of Posidonia
oceanica (L.) Delile meadows in the territorial waters of the Maltese Islands. Final Report. Geological
Assistance & Services s.r.l. (G.A.S.) Bologna, Italy, iii + 176pp
ADI Associates & Scott Wilson. 2008. Detailed investigation and feasibility studies on Land Reclamation at two
indicated search areas, Malta. Technical Report 1; Volume 1. Report prepared for Malta Environment and
Planning Authority.
Micallef, A.; Foglini, F.; LeBas, T.; Angeletti, L.; Maselli, V.; Pasuto, A. & Taviani, M. 2013. The submerged
paleolandscape of the Maltese Islands: Morphology, evolution and relation to Quaternary environmental
change. Marine Geology. 335: 129-147
35
Species typical of this habitat type and which have been specifically studied in Malta
include the Noble Pen Shell Pinna nobilis which is listed in Annex IV of the Habitats
Directive105. Such studies were carried out in four study areas located within Marine
Protected Areas declared through Government Notice 851 of 2010. The surveys were
carried out in January and February 2012 as a follow-up of a population assessment
carried out in December 2006 in one of the protected areas. The population
abundance of this species was low at all four study sites (c. 0.2 individuals/100m2)
which implies a significant decrease in abundance from 2006 (c. 1.8
individuals/100m2). The mean age of the population studied is about 2 years. The
abundance of young individuals implies an unstable population with high mortality
rate. Further assessments are currently being undertaken to assess the conservation
status of this species in Malta, and possible reasons for decline.
Other typical species include the echinoderm Paracentrotus lividus which is listed in
the Bern Convention, SPA and Biodiversity Protocol as well as LN 311 of 2006 (as
amended) as a species whose taking in the wild and exploitation may be subject to
management measures. Research is required to elucidate current exploitation levels
of P. lividus, although the species is not considered threatened in the Maltese
Islands.
Pressures:
Assemblages on shallow sublittoral sediment are subject to various anthropogenic
pressures, both land-based and sea-based, mainly as a consequence of the
concentration of anthropogenic activities in coastal waters.
Bare sediments of the shallow sublittoral are subject to physical damage and
nutrient enrichment, both of which may lead to changes in the composition or
characteristics of the substrate. Activities which exert such pressures on this habitat
type include aquaculture which is generally associated with nutrient enrichment,
leading to changes in sediment characteristics, and with disturbance of such
sediments through cage moorings (J.A. Borg & P.J. Schembri, personal
communication). Intense recreational activities in Maltese bays during the summer
months are also considered to be important sources of pressures on this habitat
type. This particularly applies to boating activities in innermost parts of bays, causing
disturbance of the sediment through moorings and anchoring. On a localised scale,
the sinking of vessels as diving attractions and dumping of spoil in the marine
environment are associated with impacts on this habitat type (J.A. Borg & P.J.
Schembri, personal communication). Vessels are generally sunk on bare sand
intentionally with a view to avoid impacts on the biodiversity-rich seagrasses, while
dumping of solid waste should only take place within a designated spoil ground. The
extent of impacts associated with the above-mentioned pressures on bare sands is
105
Ecoserv 2012 Study on the Noble Pen Shell (Pinna nobilis) populations in three Marine Protected Areas in
Malta: marine area between Rdum Majjiesa to Ras ir-Raheb; marine area in the limits of Mgarr ix-Xini (Gozo)
and marine area in the limits of Dwejra (Gozo). MEPA call for tenders: T 04/2011
36
not known. However the dynamic nature of this habitat type should be taken into
consideration when assessing extent of impacts, including its potential for recovery.
Assessments of impacts on Posidonia oceanica meadows have been carried out on
localised areas, rendering quantification of such impacts at a National scale difficult.
While not directly exploited, this habitat type is known to be potentially significantly
affected by anchoring and deployment of moorings, aquaculture, dredging,
discharges, particularly cooling waters from power plants and terrestrial runoff106. In
line with EC Regulation 1967 of 2006107, the use of towed fishing gears on seagrass
meadows is prohibited. However these meadows can be affected by other types of
fishing taking place on P. oceanica meadows such as trammel nets and fish traps (J.A.
Borg & P.J. Schembri, personal communication). The extent of impact of such fishing
activities on P. oceanica meadows is not known..
Pressures from moorings and anchoring are mainly expected within enclosed bays
and other areas which are frequented by pleasure boats108. Moorings and anchoring
can result in impacts related to physical loss as well as interference with hydrological
processes. Although the impacts of anchoring are widely known109, this pressure
cannot be quantified locally in view of the fact that, with the exception of one
anchoring zone designated on a yearly basis in Comino, there is no official
designation of anchoring zones or no-anchoring zones in the rest of Malta. On the
other hand, studies related to beach replenishment projects in St. George’s Bay
(Malta) attributed lower shoot densities of P. oceanica to anthropogenic
disturbance, including anchoring and moorings110. Studies on one of the typical
species associated with Posidonia oceanica meadows, Pinna nobilis, carried out
within Marine Protected Areas at Rdum Majjiesa – Ras ir-Raheb, the marine area off
Mgarr ix-Xini (Gozo) and the marine area in Dwejra also refer to the potential
impacts of anchoring on such species within these areas111.
With respect to reduction in water quality, historically, P. oceanica meadows are
known to have regressed and been totally replaced by pollution–tolerant benthic
communities within harbours112. Shipping and port-related activities, particularly
106
107
108
109
110
111
112
Schembri, P.J. (1995): Threatened habitats as a criterion for selecting coastal protected areas in the Maltese
Islands. Rapport du Congres de la Commission Internationale pour l’Exploration Scientifique de la Mer
Mediterranee 34: 128
Council Regulation 1967 of 2006 concerning management measures for the sustainable exploitation of fishery
resources in the Mediterranean Sea
Borg, J.A. & Schembri P.J. (1995): The state of Posidonia oceanica (L.) Delile meadows in the Maltese Islands
(Central Mediterranean); Rapp Comm int Mer Medit 34 p123
Garcia-Charton, J.A.; Pérez-Ruzafa, A; Marcos, C.; Claudet, J; Badalamenti, F; Benedetti-Cecchi, L; Falcón, JM;
Milazzo, M; Schembri, PJ; Stobart, B; Vandeperre, F; Brito, A; Chemello, R.; Dimech, M.; Guala, I; Le Diréach, L;
Maggi, E. & Planes, S. (2008) Effectiveness of European Atlanto-Mediterranean MPAs: do they accomplish the
expected effects on populations, communities and ecosystems? Journal for Nature Conservation 16: 193-221
Borg, J.A.; Gauci, M.J.; Magro, M. & Micallef, M. 2006 Environmental Monitoring at St George’s Bay (Malta) in
connection with Beach Replenishment Works 2nd International Conference on the Management of Coastal
Recreational Resources Beaches, Yacht Marinas and Coastal Ecotourism. 25-27th October 2006, Gozo, Malta.
Ecoserv 2012 Study on the Noble Pen Shell (Pinna nobilis) populations in three Marine Protected Areas in
Malta: marine area between Rdum Majjiesa to Ras ir-Raheb; marine area in the limits of Mgarr ix-Xini (Gozo)
and marine area in the limits of Dwejra (Gozo). MEPA call for tenders: T 04/2011
Borg, J.A. & Schembri P.J. (1995): The state of Posidonia oceanica (L.) Delile meadows in the Maltese Islands
(Central Mediterranean); Rapp Comm int Mer Medit 34 p123
37
dredging within ports, are also known to have significant impacts on P. oceanica
meadows through physical loss and damage, the latter as a result of sediment
resuspension and associated increase in turbidity. Bunkering activities may also exert
pressures on Posidonia oceanica meadows through the anchoring of large vessels
and generation of turbulence by such vessels (J.A. Borg & P.J. Schembri, personal
communication).
Although coastal eutrophication might not be a significant issue in Malta, and
sewage outfalls which were previously known to affect this habitat type have been
replaced with treated effluents113, aquaculture exerts a significant pressure, albeit
localised, on Posidonia through nutrient enrichment, shading (by the cages) and
deployment of cage moorings. A case study in this regard follows from the
establishment of fish farm cages in 1991 at a depth of 12-16m. The fish farm in
question, which has now ceased operation, pre-dated current permitting systems.. In
this case, the meadows directly beneath the cages were decimated and the meadow
structure (shoot density, leaf area index and shoot biomass) was considerably
altered in the vicinity of the cages114. These changes were attributed to the elevated
nutrient levels and high sedimentation rates near the cages, which led to a high
epiphytic cover of the leaves, causing a reduction in the light intensity reaching the
photosynthetic tissues, possibly limiting photosynthesis and potentially causing
death of the plant due to a reduced oxygen flux from the leaves to the below-ground
organs115. These effects were noticed up to a distance of 200m. Borg et al. (2006)
imply recovery of P. oceanica meadows following cessation of fish farm operation
through a significant increase in shoot density116. Current permitting processes are
geared towards preventing such impacts117. Within this context, reference is hereby
being made to the aquaculture strategy for Malta (2012)118.
Coastal development is also known to have resulted in changes in hydrographical
conditions and caused regression of seagrass meadows. A beach replenishment
event which took place in 1990 following deposition of dredged marine sediment
onshore (Birżebbuġa Bay) has resulted in the complete degradation of P. oceanica
meadows through the movement of the sediment by wave action and currents
offshore119. Beach replenishment does not necessarily imply such degradation,
indeed,monitoring surveys within a site, St. George’s Bay, subject to a more recent
113
114
115
116
117
118
119
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. and Jones, M.B. 2009 Occurrence and distribution of
different bed types of seagrass Posidonia oceanica around the Maltese Islands; Mediterranean Marine
Science 10(2); 45-61
Dimech, M.; Borg, J.A. & Schembri, P.J. 2002. Changes in the structure of a Posidonia oceanica meadow and in
the diversity of associated decapod, mollusc and echinoderm assemblages, resulting from inputs of waste
from a marine fish farm (Mata, Central Mediterranean). Bulletin of Marine Science 71(3): 1309-1321.
Dimech, M., Borg, J.A. & Schembri, P.J. (2000): Structural changes in a Posidonia oceanica meadow exposed
to a pollution gradient from a marine fish farm in Malta (Central Mediterranean). Biol. Mar. Medit. 7 (2): 361 364
Borg J. A., Micallef M. A, & Schembri P. J., 2006. Spatio-temporal variation in the structure of a deep water
Posidonia oceanica meadow assessed using non-destructive techniques. Marine Ecology 27: 320 - 327.
http://www.mrra.gov.mt/page.aspx?id=80
http://www.mrra.gov.mt/loadfile.ashx?id=1bb77c1f-f3a5-43fd-974d-23b46d44f605
Borg, J.A. & Schembri, P.J. 1993. Changes in marine benthic community types in a Maltese Bay following
beach replenishment works. Clean Seas Conference Proceedings 9-11 November 1993, Mediterranean
Conference Centre, Valletta, Malta.
38
and better planned beach replenishment project indicated that the overall state of
health of the seagrass (P. oceanica and C. nodosa) meadows appeared to have
remained unchanged following beach replenishment120.
Localised impacts on P. oceanica meadows occur from various activities including the
laying down of underwater cables and pipelines, discharges of cooling waters from
power plants and discharges of brine from desalination plants. The laying down of
cables and pipelines is considered to be a very localised one-time disturbance from
which Posidonia oceanica meadows can recover (J.A. Borg & P.J. Schembri, personal
communication.
With respect to cooling water discharges, the impact of such discharge from the
main power plant on the Maltese Islands on Posidonia has been established. Such
impact is evident through an increased epiphytic growth, a regression in the extent
of Posidonia and the replacement of the seagrass with Cymodocea nodosa and
photophilic algal assemblages121. In 2010 the rate of discharge of cooling waters was
295,000m3 although an extension to the power plant is expected to increase this to
43,000m3/hr at 8 degrees above ambient. The effects of the discharge of cooling
waters on the marine ecosystems in the area will be assessed annually as part of the
environmental permit of the power plant.
Shallow Sublittoral fine and coarse sediments
Malta supports other benthic communities associated with shallow sublittoral
sediment. Figure 9 provides an indication of the presence of fine and coarse
sediments (excluding Posidonia oceanica meadows) as extracted from the 2002 side
scan sonar surveys122, while Figure 10 provides an indication of the distribution of
benthic communities associated with shallow soft sediments identified through
localised surveys.
Communities associated with shallow sublittoral sediment include the biocoenosis of
infralittoral stones and pebbles and the biocoenosis of infralittoral gravels as
described by Borg & Schembri (2002)123. Nevertheless, these communities need to
be further studied and due to current data limitations they cannot be described or
assessed for the purposes of the MSFD.
120
121
122
123
Galdies, C. & Borg, J.A. 2006. Aerial Remote Sensing and Spatial Analysis of Marine Benthic Habitats in St
George’s Bay (Malta); 2nd International Conference on the Management of Coastal Recreational Resources
Beaches, Yacht Marinas and Coastal Ecotourism; Gozo, Malta; 81-87.
AIS Environmental Ltd. 2010. Alternative Assessment Report for the Disposal of Cooling Water – Delimara
Power Station
G.A.S. [Geological Assistance & Services] 2003. Baseline survey of the extent and character of Posidonia
oceanica (L.) Delile meadows in the territorial waters of the Maltese Islands. Final Report. Geological
Assistance & Services s.r.l. (G.A.S.) Bologna, Italy, iii + 176pp
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
39
Localised data on infralittoral stones and pebbles at Dwejra (Gozo) indicates that
such habitat types may be characterised by thin algal felt, supporting a rich
macrofauna, the most abundant being the gastropods Gibbula spp. and Osilinus
articulatus; the hermit crab Clibanarius erythropus; the Crabs Xantho poressa and
Xantho incisus; and the porcelain crab Pisidia sp124. A similar community was
recorded on infralittoral stones and pebbles along the North-eastern coast of
Malta125. Biocoenosis of coarse sands and fine gravels mixed by waves in the Dwejra
area were characterised by an impoverished epibiota (mainly by Holothuria spp.) but
a rich infauna as evidenced by the presence of numerous openings to burrows of
infaunal species.
Although the current data scenario does not allow further elaboration on this habitat
type, recent studies in relation to the gastropod Gibbula nivosa126 revealed the
possibility for this species to be associated with infralittoral cobbles and pebbles
rather than solely with Posidonia oceanica meadows as previously thought127. Evans
et al. (2011)128 indicate the possibility that this gastropod is only secondarily
associated with seagrasses, with records on seagrasses attributed to foraging. These
individuals would retreat to cobble/pebble habitat when not feeding.
Live specimens of this gastropod had not been recorded in Malta for the past two
decades and were only recently recorded at two localities in the Maltese Islands: off
western Comino and within Marsamxett Harbour. The largest population was
recorded within Marsamxett Harbour on a gently sloping bottom of gravelly sand
and silt with overlying cobbles and pebbles at 5–12 m depth129. Significantly higher
densities of Gibbula nivosa were associated with the upper pebble stratum rather
than with the underlying gravelly sand130. The overall population size in Marsamxett
Harbour was estimated around 100 000 individuals in January 2008, however this
population was subject to large temporal fluctuations in abundance131. Two live
individuals were also collected from a similar substrate type with sparser pebbles in
Comino at a depth of 18-20m132.
124
125
126
127
128
129
130
131
132
Borg, J.A., Dimech, M. & Schembri, P.J. 2004. Report on a survey of the marine infralittoral benthic habitats in
the Dwejra/Qawra area (Gozo, Maltese Islands), made in August – September 2004; Survey commissioned by
Nature Trust and the Malta Environment and Planning Authority.
ADI Associates & Scott Wilson. 2008. Detailed investigation and feasibility studies on Land Reclamation at two
indicated search areas, Malta. Technical Report 1; Volume 1. Report prepared for Malta Environment and
Planning Authority
Gibbula nivosa is listed in Annexes II and IV of the Habitats Directive;
Evans, J.; Borg, J.A. & Schembri, P.J. 2010 Rediscovery of live Gibbula nivosa (Gastropoda: Trochidae); Rapp.
Comm. int. Mer Médit., 39, 2010
Evans, J.; Borg, J.A. & Schembri, P.J. (2011) Distribution, habitat preferences and behaviour of the
critically endangered Maltese top-shell Gibbula nivosa (Gastropoda, Trochidae). Marine Biology
158: 603-611.
Evans, J.; Borg, J.A. & Schembri, P.J. 2011 Distribution, habitat preferences and behaviour of the critically
endangered Maltese top-shell Gibbula nivosa (Gastropoda: Trochidae). Marine Biology 158:603–611
Evans, J.; Borg, J.A. & Schembri, P.J. 2010 Rediscovery of live Gibbula nivosa (Gastropoda: Trochidae); Rapp.
Comm. int. Mer Médit., 39, 2010
Evans, J., Borg, J.A. & Schembri, P.J. 2011. Biology and conservation status of the endemic Maltese top-shell
Gibbula nivosa (A. Adams, 1851) (Trochidae). Tentacle 19
Evans, J.; Borg, J.A. & Schembri, P.J. 2010 Rediscovery of live Gibbula nivosa (Gastropoda: Trochidae); Rapp.
Comm. int. Mer Médit., 39, 2010
40
Evans et al. (2011)133, 134 indicate an estimated extent of occurrence of this species as
less than 100km2 while its area of occupancy is less than 10km2 135. The population is
also deemed to be fragmented given that the species is only known from a single site
at each of the two localities. Furthermore, populations in sites where it was recorded
in the past have not been recently observed and Gibbula nivosa may have become
extinct within these sites. In this regard, this gastropod is considered to be ‘critically
endangered’ under the IUCN (2001) criteria136.
Benthic habitats associated with shallow sublittoral mud and/or mixed sediments
have not been studied in enough detail to enable the assessment of status as per
MSFD requirements. In general, muddy substrates characterise enclosed harbour
areas along the Maltese coastline. Such muds are known to support assemblages
dominated by Cymodocea nodosa or Halophila stipulacea137. However these areas
are considered to be highly disturbed by the harbour activities. Mixed sediments
composed of gravely muddy sands are also associated with the presence of
Cymodocea nodosa and Spatangus purpureus or Caulerpa racemosa.
133
134
135
136
137
Evans, J.; Borg, J.A. & Schembri, P.J. 2011 Distribution, habitat preferences and behaviour of the critically
endangered Maltese top-shell Gibbula nivosa (Gastropoda: Trochidae). Marine Biology 158:603–611
Evans, J., Borg, J.A. & Schembri, P.J. 2011. Biology and conservation status of the endemic Maltese top-shell
Gibbula nivosa (A. Adams, 1851) (Trochidae). Tentacle 19
Evans, J.; Borg, J.A. & Schembri, P.J. 2011 Distribution, habitat preferences and behaviour of the critically
endangered Maltese top-shell Gibbula nivosa (Gastropoda: Trochidae). Mar Biol 158:603–611
Evans, J.; Borg, J.A. & Schembri, P.J. 2011 Distribution, habitat preferences and behaviour of the critically
endangered Maltese top-shell Gibbula nivosa (Gastropoda: Trochidae). Mar Biol 158:603–611
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
41
Figure 9: Presence of fine and coarse sediments (excluding Posidonia oceanica meadows)
in shallow waters as identified through a side-scan sonar survey carried out in 2002138.
138
G.A.S. [Geological Assistance & Services] 2003. Baseline survey of the extent and character of Posidonia
oceanica (L.) Delile meadows in the territorial waters of the Maltese Islands. Final Report. Geological
Assistance & Services s.r.l. (G.A.S.) Bologna, Italy, iii + 176pp
42
Figure 10: Distribution of communities associated with Shallow Sublittoral Sediment in
Malta (Sources: Borg & Schembri, 2002139, Borg et al. 2004140; ADI Associates & Scott
Wilson, 2008141)
1.3.5 Shelf sublittoral rock and biogenic reef
Benthic communities associated with shelf sublittoral rock are poorly known in
Malta. Some data originates from localised surveys including a description of an
expanse of barren rock at a depth of circa 120m in the marine area of the islet of
Filfla, off the southwestern coast of Malta (Figure 11). This stretch of seabed
supports tall hydroids possibly of the species Nemertesia ramosa. However, there
are relatively few studies which describe this type of habitat and such data scenario
precludes the possibility for assessing the extent of the communities associated with
shelf sublittoral rock.
139
140
141
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
Borg, J.A.; Dimech, M. & Schembri, P.J. 2004. Report on a survey of the marine infralittoral benthic habitats in
the Dwejra/Qawra area (Gozo, Maltese Islands) made in August – September 2004. Survey commissioned by
Nature Trust and the Malta Environment and Planning Authority
ADI Associates & Scott Wilson. 2008. Detailed investigation and feasibility studies on Land Reclamation at two
indicated search areas, Malta. Technical Report 1; Volume 1. Report prepared for Malta Environment and
Planning Authority.
43
This substrate type in the Mediterranean is known to support coralligenous
biocoenosis described as two main types of assemblages: Lithophyllo-Halimedetum
tunae and Rodriguezelletum straforelloi142. The presence of these assemblages has
not been specifically reported for Malta, although they are known to occur at depths
between 90-120m in the Siculo-Tunisian region143. The depth at which such
assemblages occur depend on the light intensity. The closest description of a benthic
habitat which may fit within the definition of coralligenous communities originates
from localised marine surveys within shallow caves and on shaded vertical rock faces
at relatively shallow depths not exceeding 42m. These communities were briefly
described in previous sections.
Records of the occurrence of species which are typical of such communities in Malta
do exist, albeit the data available is very scant. Corallium rubrum is one such species
which has been identified in Malta and has been recently observed at depths
between 585m and 819m144. Very little is known about the distribution and status of
Corallium rubrum at intermediate depths (60-300m)145. Corallium rubrum has been
commercially harvested since ancient times for its red axial calcitic skeleton146.
Historical data indicates that this species was fished between the period 1984-1987
at around depths of 170 – 200m147, however such exploitation has now ceased. This
species is strictly protected and trade of this species is illegal 148.
Pressures:
Although the pressures on this habitat type have not been documented, it is not
expected to be subject to any significant pressure.
Some species associated with shelf sublittoral rock, such as Corallium rubrum may
also be subject to exploitation, however this activity does not take place any longer
and presumably the population of such species should be recovering from past
overexploitation.
142
143
144
145
146
147
148
Ballesteros, E. 2006. Mediterranean Coralligenous Assemblages: A synthesis of present knowledge.
Oceanography and Marine Biology: An Annual Review, 2006, 44, 123-195
Ballesteros, E. 2006. Mediterranean Coralligenous Assemblages: A synthesis of present knowledge.
Oceanography and Marine Biology: An Annual Review, 2006, 44, 123-195
Taviani, M.; Freiwald, A.; Beuck, L.; Angeletti, L.; Remia, A.; Vertino, A.; Dimech, M. & Schembri, P.J. (2010):
The deepest known occurrence of the precious red coral Corallium rubrum (L. 1758) in the Mediterranean Sea
in Bussoletti, E., D. Cottingham, A. Bruckner, G. Roberts, and R. Sandulli (editors). 2010. Proceedings of the
International Workshop on Red Coral Science, Management, and Trade: Lessons from the Mediterranean.
NOAA Technical Memorandum CRCP-13, Silver Spring, MD 233 pp.
Costantini, F.; Taviani, M.; Remia, A.; Pintus, E.; Schembri, P.J. & Abbiati, M. 2010. Deep-water Corallium
rubrum from the Mediterranean Sea: preliminary genetic characterisation. Marine Ecology 31: 261-269
ditto
Deidun, A.; Tsounis, G.; Balzan, F. & Micallef, A. 2010. Records of black coral (Antipatharia) and red coral
(Corallium rubrum) fishing activities in the Maltese Islands. Marine Biodiversity Records, Marine Biological
Association of the United Kingdom doi:10.1017/S1755267210000709; Vol. 3; e90; 2010 Published online
The species is protected in the Maltese Islands since 1999, and is currently listed in Schedule VI (Animal and
Plant species of National Interest in need of Strict Protection), and consequently covered by Regulation 25 of
the Flora, Fauna and Natural Habitats Protection Regulations, 2006 (Legal Notice 311 of 2006 as amended).
44
Figure 11: Distribution of known assemblages belonging to the Shelf Sublittoral Rock & Biogenic Reef
category (Sources: AIS Environmental Ltd. & MEPA, 2006149; Dimech et al., 2004150)
149
150
AIS Environmental Ltd. & Malta Environment and Planning Authority. 2006. Marine Scientific Surveys around
Filfla for its conservation. Acoustic and Video Report, September 2006. Structural Funds Programme Malta
2004 – 2006.
Dimech, M.; Borg J.A. & Schembri P.J. (2004) Report on a video survey of an offshore area off Zonqor Point
(south-eastern coast of Malta), made in April 2004 as part of baseline ecological surveys in connection with
the establishment of an ‘aquaculture zone’. Report I - Preliminary video characterization. [Survey
commissioned by the Malta Environment and Planning Authority]. Msida, Malta: Malta University Services
Ltd; pp 14 + Figs 1–4+video[2DVDs]
45
1.3.6 Shelf sublittoral sediment
Shelf sublittoral sediments occupy a substantial extent of the seabed. Data collected
by the Fisheries trawl surveys carried out annually on soft sediments between
depths of 45 – 800m may shed light on the communities associated with shelf
sublittoral sediment which are otherwise poorly documented in Malta. This analysis
is currently being undertaken through collaboration between the University of Malta
and the Fisheries Department, however it has not been finalised at the time of
writing this document. Figure 12 provides an indication of the distribution of known
benthic habitats which form part of the Shelf Sublittoral Sediment habitat category.
In general, shelf sublittoral sediments within the 50-100m depth zone are
characterised by sandy substrata, while at depths greater than 100m, muds would
prevail.
Published analysis of Fisheries data indicate that at depths between 100–250 m the
demersal fauna associated with shelf sublittoral sediment was dominated by
commercial species of fish and cephalopods (in particular Mullus barbatus and Ilex
coindetti) and non-commercial species in particular the crinoids Leptometra
phalangium and Antedon mediterranea as well as juveniles of Parapaneus
longirostris151. High densities of Leptometra phalangium recorded through the trawl
surveys is possibly also due to the aggregation of such species on the sides of
trawling lanes to feed on the suspended sediments152.
Studies on sublittoral muds in open areas at depths between 90-103m indicate the
absence of macroalgae and the presence of megafauna mainly represented by the
echinoderms Stylocidaris affinis, Astropecten species, Spatangus purpureus and
Antedon mediterranea as well as the occasional hermit crabs Pagurus sp. These
sediments are also known to support a rich infauna as indicated by the observed
burrows possibly belonging to polychaetes and crustaceans153.
Associations of coarse sediments with rhodoliths and maerl beds constitute better
known benthic communities of the shelf sublittoral. These associations are
characterised by accumulations of unattached coralline algae or rhodoliths
(Corallinales, Rhodophyta) and occasionally calcified peysonneliacean algae154. The
term ‘maerl beds’ is used when rhodoliths constitute a dominant proportion of the
151
152
153
154
Dimech, M.; Camilleri, M.; Gristina, M.; Kaiser, M.J. & Schembri, P.J. 2005., Commercial and non-target
species of deep-water trawled muddy habitats on the Maltese continental shelf. Xjenza 10; p. 18-23
ditto
Dimech M., Borg J.A., Schembri P.J. (2004) Report on a video survey of an offshore area off Zonqor Point
(south-eastern coast of Malta), made in April 2004 as part of baseline ecological surveys in connection with
the establishment of an ‘aquaculture zone’. Report I - Preliminary video characterization. [Survey
commissioned by the Malta Environment and Planning Authority]. Msida, Malta: Malta University Services
Ltd; pp 14 + Figs 1–4+video[2DVDs]
Bordehore, C., Borg, J.A., Lanfranco, E., Ramos-Espla, A.; Rizzo, M.; Schembri, P.J. (2000): Trawling as a major
threat to Mediterranean Maerl beds. Proceedings of the first Mediterranean Symposium on Marine
Vegetation (Ajaccio, 3-4 October 2000)
46
sediment layer (P.J. Schembri, personal communication). All grades ranging from
sparse rhodoliths to full maerl beds occur in Malta.
In the Mediterranean, maerl beds occur in the transition zone between the lower
infralittoral and upper circalittoral, although sparse rhodoliths occur at other
depths155,156. The depth limit depends primarily on the degree of light penetration
and the high degree of light penetration in the Mediterranean can explain the
common occurrence of live coralline algae at a water depth of 51-90m, which far
exceeds most other maerl beds in the NE Atlantic157.
The major maerl bed in Malta covers an extent of circa 20km2 of the seabed off the
North-eastern coast of Malta at 30-100m depth158. However accumulations of
rhodoliths or unattached coralline algae were recorded from other areas:
off the Southeastern coast of Malta up to a maximum depth of 85m recorded
through a video survey as part of the Environmental Impact Assessment process.
This study area was characterised by a sparse maerl bed in association with
different types of substrata such as sand, cobbles and pebbles. Rhodoliths were
mainly restricted to the relatively shallower areas (ca. 56-69m) on a submarine
plateau. In deeper areas (ca. 90-103m), rhodolith associations were replaced by
muddy sand without rhodoliths159.
Off the North-eastern coast of Malta at depths 45-50m recorded through a
survey of two marine areas along the coast aimed at assessing the feasibility for
land reclamation projects within these areas. This area was characterised by both
maerl beds and associations with rhodoliths, with the former supporting the
gorgonian Eunicella singularis in some places160;
Off the Southwestern coast of Malta on a raised bank between mainland Malta
and the islet of Filfla161.
A recent study on the seafloor from offshore North Gozo to Southeastern Malta
delineates a wide expanse of the seabed characterised by ‘Maerl, sand and gravel’162
155
156
157
158
159
160
161
Bordehore, C., Borg, J.A., Lanfranco, E., Ramos-Espla, A.; Rizzo, M.; Schembri, P.J. (2000): Trawling as a major
threat to Mediterranean Maerl beds. Proceedings of the first Mediterranean Symposium on Marine
Vegetation (Ajaccio, 3-4 October 2000)
ADI Associates & Scott Wilson. 2008. Detailed investigation and feasibility studies on Land Reclamation at two
indicated search areas, Malta. Technical Report 1; Volume 1. Report prepared for Malta Environment and
Planning Authority
Sciberras, M.; Rizzo, M.; Mifsud, J.R; Camilleri, K.; Borg, J.A.; Lanfranco, E.; & Schembri, P.J. 2009.Habitat
structure and biological characteristics of a maerl bed off the north-eastern coast of the Maltese Islands
(central Mediterranean); Marine Biodiversity: 31: 251-264 DOI 10.1007/s12526-009-0017-4
ditto
Dimech, M.; Borg J.A. & Schembri PJ (2004) Report on a video survey of an offshore area off Zonqor Point
(south-eastern coast of Malta), made in April 2004 as part of baseline ecological surveys in connection with
the establishment of an ‘aquaculture zone’. Report I - Preliminary video characterization. [Survey
commissioned by the Malta Environment and Planning Authority]. Msida, Malta: Malta University Services
Ltd; pp 14 + Figs 1–4+video[2DVDs]
ADI Associates & Scott Wilson. 2008. Detailed investigation and feasibility studies on Land Reclamation at two
indicated search areas, Malta. Technical Report 1; Volume 1. Report prepared for Malta Environment and
Planning Authority
AIS Environmental Ltd. & Malta Environment and Planning Authority. 2006. Marine Scientific Surveys around
Filfla for its conservation. Acoustic and Video Report, September 2006. Structural Funds Programme Malta
2004 – 2006.
47
(Figure 13). Experts are of the opinion that the area indicated as ‘maerl, sand and
gravel’ through this study reflects the actual extent of shelf sublittoral coarse
sediment with rhodoliths along the North-eastern and Southeastern coast of Malta,
possibly representing all grades of coarse sediment with rhodoliths ranging from
sediment with sparse rhodoliths to full maerl beds (J.A. Borg & P.J. Schembri,
personal communication).
In Malta maerl beds are characterised by five species of maerl forming algae:
Lithothamnion minervae, Phymatolithon calcareum, Lithothamnion corallioides,
Lithophyllum racemus and Mesophyllum alternans163. Lithothamnion minervae was
the most abundant rhodolith-forming species present at the maerl bed off the
Northeastern coast of Malta. Neogoniolithon brassica-florida and Peysonnelia
species may also occur at lower quantities164. Maerl beds provide a substratum
which is exploited by a wide variety of species typical of both hard and soft
substrata. Faunal assemblages associated with maerl beds include165:
burrowing and interstitial forms that utilize the sediment underlying the
rhodoliths and the interstices between the rhodolith thalli;
sessile epifaunal organisms that utilise the rhodoliths and the stabilised upper
layer of sediment and
vagile epifauna.
The dominant faunal groups associated with maerl beds are annelids, crustaceans
and molluscs, however most animal species within these taxonomic groups occur in
other infralittoral and circalittoral habitats and are not restricted to maerl beds166.
Megafauna associated with maerl beds or associations with rhodoliths are generally
characterised by the echinoderm Stylocidaris affinis and Astropecten species.
162
163
164
165
166
Micallef, A.; Foglini, F.; LeBas, T.; Angeletti, L.; Maselli, V.; Pasuto, A. & Taviani, M. 2013. The submerged
paleolandscape of the Maltese Islands: Morphology, evolution and relation to Quaternary environmental
change. Marine Geology. 335: 129-147
Lanfranco, E.; Rizzo, M.; Hall-Spencer, J.; Borg, J.A. & Schembri, P.J. 1999. Maerl-forming coralline algae and
associated phytobenthos from the Maltese Islands. The Central Mediterranean Naturalist 3(1): 1-6.
Lanfranco, E.; Rizzo, M.; Hall-Spencer, J.; Borg, J.A. & Schembri, P.J. 1999. Maerl-forming coralline algae and
associated phytobenthos from the Maltese Islands. The Central Mediterranean Naturalist 3(1): 1-6.
Sciberras, M.; Rizzo, M.; Mifsud, J.R; Camilleri, K.; Borg, J.A.; Lanfranco, E.; & Schembri, P.J. 2009.Habitat
structure and biological characteristics of a maerl bed off the north-eastern coast of the Maltese Islands
(central Mediterranean); Marine Biodiversity: 31: 251-264 DOI 10.1007/s12526-009-0017-4
ditto
48
Figure 12: Distribution of known assemblages belonging to the Shelf Sublittoral Sediment category
(Sources: Borg & Schembri, 2002167; AIS Environmental Ltd. & MEPA, 2006168; Dimech et al., 2004169)
167
168
169
Borg, J.A. & Schembri, P.J. (2002) Alignment of marine habitat data of the Maltese Islands to conform to the
requirements of the EU habitats directive (Council Directive 92/43/EEC). [Report Commissioned by the Malta
Environment and Planning Authority]. Malta: Independent Consultants; 136pp + Figs 1-23
AIS Environmental Ltd. & Malta Environment and Planning Authority. 2006. Marine Scientific Surveys around
Filfla for its conservation. Acoustic and Video Report, September 2006. Structural Funds Programme Malta
2004 – 2006.
Dimech, M.; Borg J.A. & Schembri P.J. (2004) Report on a video survey of an offshore area off Zonqor Point
(south-eastern coast of Malta), made in April 2004 as part of baseline ecological surveys in connection with
the establishment of an ‘aquaculture zone’. Report I - Preliminary video characterization. [Survey
commissioned by the Malta Environment and Planning Authority]. Msida, Malta: Malta University Services
Ltd; pp 14 + Figs 1–4+video[2DVDs]
49
Figure 13: Area characterised by ‘Maerl, Sand and Gravel’ as indicated in Micallef et al.;
2013170
Pressures
The major pressure on Shelf sublittoral sediment is caused by trawling or other
fishing activity. Fishing disturbance may cause shifts in the benthic community
structure that particularly affect mobile scavenging species, which are probably the
most food-limited trophic group on muddy seabeds. However, it must be pointed
out that trawling within the Fisheries Management Zone is controlled as per EC
Regulation 1967 of 2006171.
Maerl beds are fragile habitats occurring in localised areas within coastal areas and
supporting many rare, unusual and scientifically interesting species172. This coupled
to the slow growth of rhodoliths implying slow recovery from perturbations, renders
maerl beds highly susceptible to anthropogenic disruptions. Maerl beds are
threatened by fishing activities, particularly trawling which can lead to physical and
biological degradation of this benthic habitat173.
170
171
172
173
Micallef, A.; Foglini, F.; LeBas, T.; Angeletti, L.; Maselli, V.; Pasuto, A. & Taviani, M. 2013. The submerged
paleolandscape of the Maltese Islands: Morphology, evolution and relation to Quaternary environmental
change. Marine Geology. 335: 129-147
Dimech, M.; Camilleri, M.; Hiddink, J.G.; Kaiser, M.J.; Ragonese, S. & Schembri, P.J. 2008. Differences in
demersal community structure and biomass size spectra within and outside the Maltese Fishery Management
Zone (FMZ) Scientia Marina 72(4) December 2008, 669-682
BIOMAERL Team 2001; Conservation and Management of NE Atlantic and Mediterranean maerl beds;
International Workshop/Conference on ‘The Scientific Basis for Conservation Management of Maerl Grounds’
ditto
50
Maerl is considered to be very sensitive to suspended sediment, hence trawling and
other activities such as aquaculture174 and dredging are expected to impact on maerl
beds through physical damage175. On the other hand, given that the extent of maerl
beds may actually be wider than presently known, level of impacts cannot be
assessed at this stage
Furthermore, it was clearly shown that fishing with set trammel nets on maerl beds
leads to selective removal and mortality of large rhodoliths as they become
entangled within the nets. The removal of the largest rhodoliths might lead to longterm shifts in maerl community structure in Malta, given their slow growth rate.
Bunkering areas, some of which overlap with the presence of maerl beds are also
considered to be a source of pressure since anchoring of large vessels would lead to
physical damage of this habitat type (J.A. Borg & P.J. Schembri, personal
communication).
174
175
In Malta, one of the tuna farms is located on the sparse maerl bed recorded off the Southeastern coast of
Malta.
AIS Environmental Ltd. & Malta Environment and Planning Authority. 2006. Marine Scientific Surveys around
Filfla for its conservation. Acoustic and Video Report, September 2006. Structural Funds Programme Malta
2004 – 2006.
51
1.3.7 Upper bathyal rock and biogenic reef
Marine habitats on rock at this depth stratum are not well-known in Malta.
Furthermore, detailed topographic data which could channel biological
investigations to particular sites potentially supporting biotic assemblages on upper
bathyal rock is limited. This depth stratum is surveyed as part of the fisheries trawl
surveys, generally carried out on soft substrata.
The information which is currently available was in fact generated by accidental
collection of deep-water corals during fishery trawl surveys, which occurrence was
subsequently corroborated through ROV surveys176,177. During the 2003 MEDITS and
GRUND cruises, a limited number of exploratory hauls were made on hard grounds
off the southern to south-western coast of Malta. Live reef-building corals Lophelia
pertusa and Madrepora oculata and the solitary coral Desmophyllum dianthus were
collected from depths between 395m-617m. An ROV survey of an escarpment in the
vicinity of the area from which corals were collected revealed the presence of M.
oculata at depths 453-612m and to a lesser degree L. pertusa at depths 453-576m178.
The white coral community is associated with Corallium rubrum and other
gorgonians. The presence of live Corallium rubrum colonies was also documented
during a 2007 cruise (R⁄V Urania MARCOS) in a depth range between 585m and
819m179,180.
Species associated with the white corals, which were either collected by the
exploratory hauls or observed by the ROV surveys, include the solitary coral
Desmophyllum dianthus, the symbiotic polychaete Eunice norvegica, and the bivalve
species Spondylus gussonii and Asperarca nodulosa. Other species recorded include
the echinoid Cidaris cidaris, the gastropod Coralliophilia richardi, and the crab
Anamanthia rissoana, all of which seem to associate with living deep-water coral
banks181. In particular Coralliophilia richardi is strictly associated with Lophelia and
very likely with Madrepora species182.
176
177
178
179
180
181
182
Schembri, P.J.; Dimech, M.; Camilleri, M. & Page, R. (2007) Living deep-water Lophelia and Madrepora corals
in Maltese waters (Strait of Sicily, Mediterranean Sea). Cahiers de Biologie Marine 48: 77-83.
Freiwald, A.; Beuck, L.A.; Ruggeberg, A.; Taviani, M.; Hebbeln, D. & R/V Meteor cruise M70-1 participants.
2009. The white coral community in the central Mediterranean sea revealed by ROV surveys. Oceanography;
22 (1); 58-74.
ditto
Taviani, M.; Freiwald, A.; Beuck, L.; Angeletti, L.; Remia, A.; Vertino, A.; Dimech, M. & Schembri, P.J. (2010):
The deepest known occurrence of the precious red coral Corallium rubrum (L. 1758) in the Mediterranean
Sea in Bussoletti, E., D. Cottingham, A. Bruckner, G. Roberts, and R. Sandulli (editors). 2010. Proceedings of
the International Workshop on Red Coral Science, Management, and Trade: Lessons from the Mediterranean.
NOAA Technical Memorandum CRCP-13, Silver Spring, MD 233 pp.
Costantini, F.; Taviani, M.; Remia, A.; Pintus, E.; Schembri, P.J. & Abbiati, M. 2010. Deep-water Corallium
rubrum from the Mediterranean Sea: preliminary genetic characterisation. Marine Ecology 31: 261-269
Schembri, P.J.; Dimech, M.; Camilleri, M. & Page, R. (2007) Living deep-water Lophelia and Madrepora corals
in Maltese waters (Strait of Sicily, Mediterranean Sea). Cahiers de Biologie Marine 48: 77-83.
Taviani, M., Angeletti, L., Dimech, M., Mifsud, C., Freiwald, A., Harasewych, M.G., Oliverio, M. 2009.
Coralliophilinae (Gastropoda: Muricidae) associated with deepwater coral banks in the Mediterranean.
Nautilus 123 (3), 106-112.
52
Two other research cruises have been carried out in the area: MEDCOR 2009 and
DECORS 2011 (P.J. Schembri, personal communication). The results of these cruises
have not been published as yet, however Taviani et al. (2011)183 indicate that a
complete swath bathymetric mapping of the area covered by active coral growth on
the escarpment has been completed through MARCOS 2007 and MEDCOR 2009. The
same authors indicate that this escarpment is located within a critical sector of the
Mediterranean Sea, under the influx of two major water masses, the superficial
inflow of Modified Atlantic Water and the deep counterflow of the Levantine
Intermediate Water.
Historical records indicate the presence of black coral (Antipatharia) in the upper
bathyal (500-600m), the distribution of which is however unknown to date184. Black
corals used to be exploited in Malta and according to Deidun et al. (2010)185 fishing
for black coral ceased for two main reasons: the great depths involved, making the
use of coral dredging or netting necessary in order to access the coral populations,
and the fact that coral dredges have been prohibited in the EU since 1994.
Pressures:
The coral communities described above are located on a near vertical escarpment
which is not trawlable. Therefore, based on the current data available, these
assemblages are not considered to be subject to significant anthropogenic pressures,
since they are naturally protected by the benthic topography (P.J. Schembri,
personal communication).
1.3.8 Upper bathyal sediment
The benthic assemblages associated with the upper bathyal are not well known in
Malta and the only information which is available originates from Fisheries surveys.
As stated previously, data generated through the Fisheries surveys is currently being
analysed, however this analysis has not been finalised at the time of writing this
document.
Muddy sediments between 200-350m, within the 25 nautical mile Fisheries
Management Zone are reported to support commercial species typical of deep
183
184
185
Taviani, M., Angeletti, B., Antolini, A., Ceregato, A., Froglia, C., Lopez Correa, M., Montagna, P., Remia, A.,
Trincardi, F. & Vertino, A. 2011. Geo-biology of Mediterranean Deep-water coral ecosystems. Marine
Research at CNR, National Research Council of Italy, Department of Earth and Environment, Volume DTA/062011.
Deidun, A.; Tsounis, G.; Balzan, F. & Micallef, A. 2010. Records of black coral (Antipatharia) and red coral
(Corallium rubrum) fishing activities in the Maltese Islands. Marine Biodiversity Records, Marine Biological
Association of the United Kingdom doi:10.1017/S1755267210000709; Vol. 3; e90; 2010 Published online
Deidun, A.; Tsounis, G.; Balzan, F. & Micallef, A. 2010. Records of black coral (Antipatharia) and red coral
(Corallium rubrum) fishing activities in the Maltese Islands. Marine Biodiversity Records, Marine Biological
Association of the United Kingdom doi:10.1017/S1755267210000709; Vol. 3; e90; 2010 Published online
53
waters including the giant red shrimp (Aristeomorpha foliacea), the Norway Lobster
(Nephrops norvegicus) and Blackmouth Catshark (Galeus melastomus). These
commercial species are accompanied by other species which are not exploited in
Malta such as decapod crustaceans Plesionika heterocarpus, Pasiphaea sivado and
Sergestes corniculum186. However the species composition varies with depth and
these species are not necessarily representative of this habitat type187.
The ROV survey of an escarpment off the Southwestern coast of Malta indicated the
presence of bathyal muds along the seabed adjacent to the near-vertical wall, on
which sessile octocorals Isidella elongata and Funiculina quadrangularis were
observed. These muds have been bioturbated by crustacean burrows and by grazing
tracks of holothuroids and cidaroid echinoids188. These species are typical of bathyal
muds and the ROV survey confirmed the presence of these assemblages in deep
waters.
However at this stage, there is no further data which allows the characterisation of
the benthic assemblages associated with this type of habitat type and although the
sampling sites used for Fisheries surveys may provide an indication of the occurrence
of such habitat type within Malta, the current data scenario is not deemed adequate
to allow the determination of the extent and distribution of this habitat type and
assessment of status.
Pressures:
In terms of pressures, this habitat type is subject to fishing activities, namely trawling
for commercial species and possibly bottom long-lining. However, it should be
pointed out that trawling within the Fisheries Management Zone is regulated in line
with EC Regulation 1967 of 2006 hence the fishing pressure on this type of habitat
within the Fisheries Management Zone would be less than that on the same habitats
outside which are known to be characterised by lower abundances and biomass of
commercial species189. Furthermore, the effects of trawling are generally more
pronounced on non-target species, with the commercial catches being less sensitive
to a moderate level of trawling effort190.
186
187
188
189
190
Dimech, M. Camilleri, M.;. Kaiser, M.J., Schembri, P.J. 2007. Demersal Assemblages on deep water trawling
grounds off the Maltese Islands: Management Implications; Comm. int. Mer Médit., 38
Dimech, M.; Camilleri, M.; Hiddink, J.G.; Kaiser, M.J.; Ragonese, S. & Schembri, P.J. 2008. Differences in
demersal community structure and biomass size spectra within and outside the Maltese Fisheries
Management Zone (FMZ). Scientia Marina, 72 (4): 669-682.
Freiwald, A.; Beuck, L.A.; Ruggeberg, A.; Taviani, M.; Hebbeln, D. & R/V Meteor cruise M70-1 participants.
2009. The white coral community in the central Mediterranean sea revealed by ROV surveys. Oceanography;
22 (1); 58-74.
Dimech, M.; Camilleri, M.; Hiddink, J.G.; Kaiser, M.J.; Ragonese, S. & Schembri, P.J. 2008. Differences in
demersal community structure and biomass size spectra within and outside the Maltese Fisheries
Management Zone (FMZ). Scientia Marina, 72 (4): 669-682.
Dimech, M.; Camilleri, M.; Gristina, M.; Kaiser, M.J. & Schembri, P.J. 2005., Commercial and non-target
species of deep-water trawled muddy habitats on the Maltese continental shelf. Xjenza 10; p. 18-23
54
The mooring blocks of Fish Aggregating Devices may also be a source of impact on
this habitat type191.
191
Pace, R.; Dimech, M. & Schembri, P.J. (2007) Distribution and density of discarded limestone slabs used in the
traditional Maltese lampuki fishery. Rapport du Congrès de la Commission Internationale pour l'Exploration
Scientifique de la Mer Méditerranée 38: 568.
55
1.4
Pressures and Impacts
The first Water Catchment Management Plan192 for the Maltese Islands identifies
and discusses pressures on coastal waters, namely point sources of pollution from
urban and industrial sources, diffuse sources from industrial sources and urban
runoff, and hydromorphological alterations. The information provided in the Water
Catchment Management Plan (WCMP) is applicable for the purposes of the MSFD.
However it is worth noting that since the publication of the first WCMP, all municipal
wastewater is being treated and only second class treated wastewater is now
discharged into coastal waters.
The assessment of pressures on benthic habitats for the purposes of the MSFD,
builds on the pressure analysis carried out as part of the Water Framework Directive,
but covers a wider range of maritime activities and associated pressures in line with
Annex III of the Directive.
Table 5 provides an indication of the maritime activities which can potentially give
rise to pressures and impacts on benthic habitats. The extent of benthic habitats
affected by the various maritime activities was derived through superimposition of
the activities or the pressures themselves (such as occurrence of non-indigenous
species) on the benthic habitats. The significance or importance of such effects was
assessed through a combination of a semi-quantitative assessment of the extent of
affected benthic habitats, an evaluation of the reversibility or otherwise of the effect
and expert judgement. The latter contributed significantly to the assessment of
pressures, especially in view of the current data scenario with respect to benthic
habitats. Table 6 reflects the outcome of the assessment of pressures on each MSFD
habitat type.
The assessment of pressures and impacts on benthic habitats was used to inform the
overall assessment of status of the MSFD benthic habitat types. In particular, the
assessment of pressures sheds light on the ‘future prospects’ of the habitat type in
line with the recommendations put forward through the Habitats Directive guidance
document193. Within this context, future trends of habitats is dependant on threats
which will have a negative influence and on conservation measures and other
provisions which will have a positive influence.
192
193
http://www.mepa.org.mt/topic-wcmp
Assessment and reporting under Article 17 of the Habitats Directive: Explanatory Notes & Guidelines for the
period 2007-2012. Final Draft. April 2011.
56
Table 5: List of activities and associated pressures on benthic habitats under consideration
for the purposes of the MSFD
Sector
Activity
Annex III Pressure
Fisheries
Trawling
Aquaculture
N/A
Man-made
structures
Land reclamation or Coastal
Defence
Physical Loss
Physical Damage
Physical Damage
Contamination by hazardous substances
Nutrient and Organic Enrichment
Physical Loss
Physical Damage
Interference with Hydrological Processes
Physical Loss
Physical Damage
Interference with Hydrological Processes
Submarine cables and pipelines
Extraction of
resources
Energy
Desalination/water abstraction
Marine-based renewable
energy generation
Physical Loss
Physical Damage
Interference with Hydrological Processes
Physical Loss
Physical Damage
Contamination by hazardous substances
Physical Loss
Physical Damage
Interference with Hydrological Processes
Contamination by hazardous substances
Physical Loss
Physical Damage
Interference with Hydrological Processes
Contamination by hazardous substances
Physical Damage (through anchoring)
Contamination by hazardous substances
Non-indigenous species
Physical Damage (through anchoring)
Physical Loss
Physical Damage
Interference with Hydrological Processes
Contamination by hazardous substances
Non-indigenous species
Physical Damage
Physical Damage
Physical Loss
Physical Damage
Physical Damage
Contamination by hazardous substances
Interference with Hydrological Processes
Contamination by hazardous substances
Contamination by hazardous substances
Nutrient and Organic Enrichment
Contamination by hazardous substances
Nutrient and Organic Enrichment
Marine hydrocarbon extraction
Shipping
(including Port
Operations)
Coastal Defence
Fuel terminals/Bunkering
Dredging
Maritime Traffic
Tourism and
Recreation
(including
yachting)
Boating
Yachting/Marinas
Waste
Diving
Sinking of vessels
Disposal of solid waste
Defence
Dumping of munition
Land-based
activities
Industry
Agriculture
Municipal waste water
discharge
57
Table 6: Assessment of Pressures on MSFD benthic habitat types. +++ = effect is of high significance; ++ = effect is of moderate significance; + = effect is
of low significance; N/A = Pressure is not applicable for the specific MSFD Habitat type; Reference to ‘Potential pressure’ implies that current data
scenario does not allow assessment of pressure on habitat type; Symbols in red indicate potential effect from planned activities currently under
assessment.
Habitats Pressures Sectors Physical Loss
Fisheries
Land/sea physical
interactions; coastal
defence (include
structures related to
harbours and marinas)
Submarine cables and
pipelines
Dredging
Marine-based
renewable energy
generation
Marine hydrocarbon
extraction
Solid waste disposal
Physical
Damage
Fisheries
Littoral Rock
and
Biogenic
Reefs
Littoral
Sediment
Shallow
sublittoral
rock and
biogenic
reefs
Shallow
sublittoral
sediment
(including
Posidonia
oceanica
meadows)
Shelf
sublittoral
rock and
biogenic
reefs
Shelf
sublittoral
sediment
Upper
bathyal rock
and biogenic
reefs
Upper
Bathyal
sediment
N/A
N/A
N/A
N/A
N/A
++
N/A
++
N/A
N/A
+
+
N/A
N/A
N/A
N/A
N/A
N/A
+
+
+
+
+
+
N/A
N/A
N/A
++
N/A
N/A
N/A
N/A
N/A
N/A
N/A
+
Potential
Potential
N/A
N/A
N/A
N/A
N/A
N/A
Potential
Potential
N/A
Potential
N/A
N/A
N/A
+
N/A
+
N/A
N/A
N/A
N/A
N/A
+
N/A
++
N/A
++
58
Habitats Pressures Sectors Aquaculture
Land/sea physical
interactions; coastal
defence (including
structures related to
harbours and marinas)
Submarine cables and
pipelines
Dredging
Marine-based
renewable energy
generation
Marine hydrocarbon
extraction
Shipping (anchoring
and bunkering)
Solid Waste disposal
Tourism and
recreation including
boating, yachting,
diving, sinking of
vessels
Defence: Dumping of
unwanted munitions
Littoral Rock
and
Biogenic
Reefs
Littoral
Sediment
Shallow
sublittoral
rock and
biogenic
reefs
Shallow
sublittoral
sediment
(including
Posidonia
oceanica
meadows)
Shelf
sublittoral
rock and
biogenic
reefs
Shelf
sublittoral
sediment
Upper
bathyal rock
and biogenic
reefs
Upper
Bathyal
sediment
N/A
N/A
N/A
++
+
+
N/A
N/A
N/A
N/A
+
+
N/A
N/A
N/A
N/A
+
N/A
+
+
+
+
N/A
Potential
+
N/A
N/A
++
N/A
N/A
N/A
N/A
N/A
N/A
N/A
+
Potential
Potential
N/A
N/A
N/A
N/A
N/A
N/A
Potential
Potential
N/A
Potential
N/A
N/A
N/A
++
Potential
++
N/A
N/A
N/A
N/A
N/A
+
N/A
+
N/A
N/A
+
++
+
++
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Potential
Potential
N/A
N/A
59
Habitats Pressures Sectors Interference
with
hydrological
processes
Land/sea physical
interactions; coastal
defence
Dredging
Contaminatio
n by
hazardous
substances
Desalination/water
abstraction
Marine-based
renewable energy
generation
Land-based activities:
industrial discharges
and emissions
Aquaculture
Dredging
Marine hydrocarbon
extraction
Shipping (including
port operations &
bunkering)
Defence: dumping of
unwanted munitions
Tourism and
recreation including
Littoral Rock
and
Biogenic
Reefs
Littoral
Sediment
Shallow
sublittoral
rock and
biogenic
reefs
Shallow
sublittoral
sediment
(including
Posidonia
oceanica
meadows)
Shelf
sublittoral
rock and
biogenic
reefs
Shelf
sublittoral
sediment
Upper
bathyal rock
and biogenic
reefs
Upper
Bathyal
sediment
+
++
N/A
+
N/A
N/A
N/A
N/A
N/A
N/A
N/A
+
N/A
N/A
N/A
N/A
+
N/A
+
+
N/A
N/A
N/A
N/A
N/A
N/A
N/A
+
N/A
+
N/A
N/A
+
N/A
+
+
N/A
N/A
N/A
N/A
N/A
N/A
+
+
+
+
N/A
N/A
N/A
N/A
N/A
+
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Potential
Potential
N/A
Potential
N/A
N/A
++
++
++
++
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
+
+
N/A
N/A
N/A
N/A
60
Habitats Pressures Nutrient and
organic
enrichment
Biological
Disturbance
Sectors boating, yachting,
diving, sinking of
vessels
Coastal, riverine and
atmospheric inputs
from land – industrial
discharges and
emissions
Coastal, riverine and
atmospheric inputs
from land – municipal
waste water discharge
Aquaculture
Coastal, riverine and
atmospheric inputs
from land – agriculture
and forestry run-off
and emissions
Coastal, riverine and
atmospheric inputs
from land – municipal
waste water discharge
Shipping (including
port operations)
Tourism and
recreation including
Littoral Rock
and
Biogenic
Reefs
Littoral
Sediment
Shallow
sublittoral
rock and
biogenic
reefs
Shallow
sublittoral
sediment
(including
Posidonia
oceanica
meadows)
Shelf
sublittoral
rock and
biogenic
reefs
Shelf
sublittoral
sediment
Upper
bathyal rock
and biogenic
reefs
Upper
Bathyal
sediment
N/A
N/A
+
+
N/A
N/A
N/A
N/A
N/A
N/A
+
+
N/A
N/A
N/A
N/A
N/A
N/A
+
++
N/A
N/A
N/A
N/A
++
N/A
++
+
N/A
N/A
N/A
N/A
++
N/A
++
N/A
N/A
N/A
N/A
N/A
+
N/A
+
+
N/A
N/A
N/A
N/A
+
N/A
+
+
N/A
N/A
N/A
N/A
61
Habitats Pressures Sectors Littoral Rock
and
Biogenic
Reefs
Littoral
Sediment
Shallow
sublittoral
rock and
biogenic
reefs
boating, yachting,
diving, sinking of
vessels
62
Shallow
sublittoral
sediment
(including
Posidonia
oceanica
meadows)
Shelf
sublittoral
rock and
biogenic
reefs
Shelf
sublittoral
sediment
Upper
bathyal rock
and biogenic
reefs
Upper
Bathyal
sediment
1.5
Assessment of Status
1.5.1 Assessment areas
On the basis of the above description of benthic habitats, the current data
availability and the distribution of marine activities, two major assessment areas
were delineated to represent the different habitat types within each MSFD
predominant habitat type category. These assessment areas incorporate the marine
area off the North-eastern coast of the Maltese Islands up to and an area off the
Southwestern coast of mainland Malta as indicated in Figure 14. Once new data
becomes available, the assessment areas may be adjusted accordingly. The Northeastern assessment area is targeted at the assessment of littoral, shallow sublittoral
and shelf sublittoral benthic habitats, while the Southwestern assessment area is
targeted at the assessment of bathyal habitats. It should be noted that the extent of
these assessment areas was delineated with the boundaries of the protected areas
as designated through Government Notice 851 of 2010 and with the coastal water
bodies as identified in Malta’s Water Catchment Management Plan, as much as
possible.
As a result of the current data scenario, in which data is mainly available for the
habitat types associated with the shallower depths, the assessment of status for the
first reporting cycle was focused on the North-eastern assessment area. The
Southwestern assessment area will be used in future reporting cycles specifically for
bathyal habitat types, since to date, these have only been recorded from this area.
It should also be noted that the Grand Harbour area designated as a Heavily
Modified Water Body through the implementation of the Water Framework
Directive for coastal water bodies, has been excluded from this assessment area. The
reason is that the habitats within this area are highly modified as a result of port
operations. Therefore such habitats will not be representative of the habitat types
under consideration. Nevertheless, pressures associated with port operations were
still taken into consideration in the assessment process and the achievement of good
status within these areas will still be sought, also taking into consideration the
existing commitments of the EU Water Framework Directive.
63
Figure 14: Proposed Assessment Areas for the assessment of benthic habitats
The North-eastern assessment area incorporates most of the activities which are
associated with pressures on the marine environment including:
Aquaculture
Bunkering areas
Historical munition dumping
ground
Land-based discharges
Marinas
Mooring and anchoring areas;
Pipelines
Planned windfarms
Power and telecommunication
cables
Spoil ground
Swimming areas
Trawling
This assessment area also covers most of the past monitoring stations for
contaminants and the most extensive Marine Protected Area designated within the
framework of the Habitats Directive (Government Notice 851 of 2010).
For most habitat types, assessment of status was restricted to these assessment
areas unless it was deemed more adequate to assess particular habitats at other
geographic scales.
64
1.5.2 Methodologies
Assessment of status of benthic habitats is based on the criteria and indicators
established by Commission Decision 477/2010/EU, also building on existing
methodologies which are currently applied for the Habitats Directive and Water
Framework Directive. The criteria and indicators for Descriptors 1, 4 and 6
reproduced hereunder are deemed to be relevant in terms of benthic habitats:
Descriptor 1: Biological Diversity is maintained. The quality and occurrence
of habitats and the distribution and abundance of species are in line with
prevailing physiographic, geographic and climatic conditions
Descriptor 4: All elements of marine food webs, to the extent that they are
known, occur at normal abundance and diversity and levels capable of
ensuring the long-term abundance of the species and the retention of their
full reproductive capacity
Descriptor 6: Sea-floor integrity is at a level that ensures that the structure
and functions of the ecosystems are safeguarded and benthic ecosystems, in
particular, are not adversely affected.
The current status of data and information on benthic habitats in Malta precludes
the possibility to apply all relevant criteria and indicators for MSFD Descriptors 1, 4
and 6. Further data would need to be collected to allow the application of all
relevant criteria and indicators.
65
Table 7 lists the criteria and indicators which were used for determination of status
for particular habitat types. However, it should be noted that assessment of status
on the basis of these selected criteria was still not possible for all habitat types, also
in view of data limitations. In such circumstances efforts have been made to
determine status through expert judgement.
66
Table 7: Criteria and indicators on which assessment of status of benthic habitats for the
first reporting cycle of the MSFD is based.
Criteria
Indicators
Methodologies (Sources)
Habitat Distribution (1.4)
Distributional range (1.4.1)
Habitat extent (1.5)
Habitat area (1.5.1)
Physical Damage, having
regard to substrate
characteristic (6.1)
Type, abundance, biomass
and areal extent of biogenic
substrate (6.1.1)
Condition of the typical
species and communities
(1.6.1); Relative abundance
and/or biomass as
appropriate (1.6.2)
Presence of particularly
sensitive and/or tolerant
species (6.2.1)
Habitat Condition (1.6)
Condition of benthic
community (6.2)
Assessment and reporting
under Article 17 of the
Habitats Directive:
Explanatory Notes &
Guidelines for the period
2007-2012. Final Draft. April
2011.
CARLIT, PREI and AMBI index
as applied for the WFD
monitoring programme
The application of habitat distribution and extent (criteria 1.4 and 1.5) criteria for
determination of status builds on the requirements of the Habitats Directive in
determining ‘Conservation Status’. According to Habitats Directive’s Article 17
guidance document, the evaluation of status based on range should consider the size
of the range in relation to the size of the favourable range and trends. Given the
current status of available data, particularly the fact that most of the data
constitutes snapshot data, the possibility to use trends to assess status through this
methodology was ruled out. The calculation of Favourable Reference Range and
Favourable Reference Areas, based on the guidance provided in Article 17 guidance
document, was possible only for habitat types of which ecological requirements are
relatively well known. Reference ranges and areas could not be determined for each
habitat also in view of the dearth of information which is available with respect to
substrate types and other physical aspects of the marine environment which would
establish the conditions for the different habitat types.
With respect to condition of benthic habitats (criteria 1.6 and 6.2), the
methodologies used in determining status are based on those currently utilised for
assessing ecological status of the Biological Quality Elements under consideration
through the Water Framework Directive. This is due to the fact that the Habitats
Directive does not specify how ‘structure and functions’ can be evaluated. As per
WFD methodologies, the ecological status is expressed as a ratio between the values
of the biological elements observed by a given body of surface water and the value
for these elements in reference conditions. However these methodologies were only
applied for habitat types which are currently being monitored as part of the
implementation of the Water Framework Directive.
67
The overall assessment of status on the basis of the above-mentioned criteria and
indicators was supplemented by information on the extent and location of pressures
in the marine environment (refer to section 1.4 of this document) and was subject to
expert judgement throughout the whole process.
With respect to the boundaries between ‘Good’ status and ‘Not Good’, the
thresholds for such boundaries were determined on a case by case basis through
expert advice. However a general indication of the basis of such thresholds is
provided in
Table 8.
Table 8: General indication for determination of thresholds between Good and Not good
status.
Moderate
Criteria
Indicators
Good Status
Poor Status
Status
Habitat
Distribution (1.4)
Distributional
range (1.4.1)
Habitat extent
(1.5)
Habitat area
(1.5.1)
Physical Damage,
having regard to
substrate
characteristic
(6.1)
Type, abundance,
biomass and
areal extent of
biogenic
substrate (6.1.1)
Habitat Condition
(1.6)
Condition of
benthic
community (6.2)
194
Condition of the
typical species
and communities
(1.6.1); Relative
abundance
and/or biomass
as appropriate
(1.6.2)
Presence of
particularly
sensitive and/or
tolerant species
(6.2.1)
The range and
extent of the
habitat type,
when compared
to favourable
reference values
and/or based on
expert
judgement, are
not significantly
altered by
anthropogenic
activities. Future
prospects secure
the long-term
viability of the
habitat type.
The range and
extent of the
habitat type,
when compared
to favourable
reference values
and/or based on
expert
judgement, have
been altered or
are likely to be
affected by
anthropogenic
factors. Future
prospects for
maintenance of
the range and
extent are good.
The range and
extent of the
habitat type,
when compared
to favourable
reference values
and/or based on
expert
judgement, have
been significantly
affected by
anthropogenic
factors in a
manner which
puts the long
term viability of
the habitat type
at risk.
The structural
194
aspects of the
benthic habitat or
the composition
and abundance of
species
associated with
the habitat type
corresponds to
undisturbed
conditions or is
only slightly
altered relative to
undisturbed
195
conditions
The structural
aspects of the
benthic habitat or
the composition
and abundance of
species
associated with
the habitat type
are indicative of
moderate
changes relative
to undisturbed
196
conditions .
The structural
aspects of the
benthic habitat or
the composition
and abundance of
species
associated with
the habitat type
are indicative of
significant
changes relative
to undisturbed
conditions
The structural aspects for marine habitats listed in the EU Habitats Directive (1110, 1120 and 1170) are
defined in Assessment and reporting under Article 17 of the Habitats Directive: Explanatory Notes &
Guidelines for the period 2007-2012. Final Draft. April 2011.
68
1.5.3 Assessment of Status
The following outlines the assessment of status for the MSFD predominant habitat
types, and where necessary, for specific habitat types (Table 10).
Littoral Rock and Biogenic Reef:
Communities of mediolittoral macroalgae characterised by Cystoseira species were
used as the indicator species of ‘Littoral Rock and Biogenic Reefs’. The status of such
communities was assessed on the basis of the range and extent covered by
Cystoseira species (in terms of length of coastline) within the north-eastern
assessment area.
In accordance with the Habitats Directive Article 17 guidance, the natural range
constitutes the spatial limits across the north-eastern assessment area within which
this habitat type occurs. The range should exclude major discontinuities due to
natural factors, which for Cystoseira on littoral rock would be mainly represented by
sandy or shingle beaches. However due to the limited extent of sandy or shingle
beaches on the Maltese Islands (total length of c.3km), they were not considered to
be major discontinuities in the range of the habitat type in question. Within this
context, the Favourable Reference Range of Cystoseira communities was considered
to be the extent of rocky coast within the north-eastern assessment area. The
Favourable Reference area on the other hand was considered to be the extent of
rocky shoreline within the north-eastern assessment excluding sandy or shingle
beaches. However this reference area is not taking into consideration the presence
of particular geomorphological features along the coastline, which would not be
colonised by Cystoseira communities. Therefore in reality, the Favourable Reference
Area of this type of community could be much less than that determined for this
reporting cycle. Such issues should be tackled in future reporting cycles.
The current range of Cystoseira communities is considered to occupy the whole
range of littoral rock (excluding harbours) along the north-eastern coast, while the
extent of coastline occupied by Cystoseira communities constitutes c. 66% of the
rocky coastline excluding sandy or shingle beaches. This percentage however does
not take into consideration the influence of geomorphological factors on the
distribution of Cystoseira communities, therefore the absence of Cystoseira from the
remaining coastline could be due to both natural and anthropogenic factors. Based
on expert judgement and the extent of coastline for which absence of Cystoseira can
be attributed with certainty to anthropogenic disturbance (approximately 3% of the
current extent of Cystoseira communities), the status of this community is
considered to be overall good in terms of habitat distribution and extent.
195
196
Based on the definition of ‘high’ and ‘good’ status as defined for the various biological quality elements as per
Water Framework Directive.
Based on the definition of ‘moderate’ status for the various biological quality elements of the Water
Framework Directive
69
Assessment of the habitat condition was extrapolated from the outcome of the
baseline monitoring, which at the time of writing this document, is being undertaken
for the purposes of the EU Water Framework Directive197. Monitoring and
assessment of status of macroalgae, as one of the Biological Quality Elements under
consideration by the WFD, was based on the CARLIT methodology as defined by
Ballesteros et al. (2007)198.
Five out of eleven stations analysed by application of the CARLIT index through the
WFD baseline monitoring are located in the north-eastern assessment area.
Calculation of the ratio between the CARLIT index and reference values (or maximum
values of the CARLIT index) calculated for Maltese coast typologies, resulted in three
of these sampled sites qualifying as ‘High’ Ecological Status and two as ‘Good’
ecological status (Figure 15). This result corroborates with the findings of the 2008
survey, which survey applied the CARLIT methodology to the whole extent of the
Maltese coast. According to this survey, most of the communities in the northeastern assessment area resulted in ‘high’ good status, with a ‘good’ status being
attributed to the water body along the coastline which until recently was subject to
effluent of untreated wastewater.
The overall status of this habitat type is considered to be good.
197
198
CIBM & Ambiente SC. 2012. Development of Environmental Monitoring Strategy and Environmental
Monitoring Baseline Surveys – Water Lot 3 – Surveys of Coastal Water – August 2012. ERDF156 - Developing
national environmental monitoring infrastructure and capacity
Ballesteros, E.; Torras, X; Pinedo, S.; Garcia, M.; Mangialajo, L. & deTorres, M. 2007. A new methodology
based on littoral community cartography dominated by macroalgae for the implementation of the European
Water Framework Directive. Marine Pollution Bulletin 55: 172-180.
70
Figure 15: Stations assessed through the CARLIT methodology as part of the WFD
monitoring regime
Littoral sediment
This predominant habitat type is represented by sandy and shingle beaches along
the Maltese coastline. Given the localised nature of such beaches, assessment of
status is based on a selection of beaches made in accordance with the following
criteria:
Beaches of which extent does not vary seasonally and are thus considered to
be permanent beaches;
Beaches of relatively significant length which can potentially support beach
ecosystems;
Natural beaches, thus excluding any beaches which have been subject to
beach replenishment projects.
The beaches which will be used in assessing status are the following (Figure 16):
Ir-Ramla and il-Bajja ta’ San Blas, on Gozo
Il-Qala ta’ Santa Marija, on Comino
Il-Bajja tal-Ġnejna, Ir-Ramla tal-Mixquqa, Ir-Ramla ta’ Għajn Tuffieħa and the
shingle beach at Fomm ir-Riħ on the southwestern coast of mainland Malta;
Ir-Ramla tat-Torri, Ir-Ramla tal-Qortin, Ir-Ramla tal-Armier, Little Armier and
il-Bajja tal-Mellieħa on the north-eastern coast of mainland Malta.
71
Figure 16: Selected sandy beaches and shingle beach for MSFD assessment purposes
In accordance with Habitats Directive Article 17 guidance document, the
distributional range of such localised habitat types would be equivalent to their
extent. Within this context, these two parameters were calculated as length of
shoreline occupied by each beach, measured on the basis of 2008 aerial
photographs. These beaches cover a total length of 2419m (Table 9:
Table 9: Estimates of lengths of selected beaches based on the 2008 aerial photographs
Beach
Length (m) calculated on the basis of the
2008 aerial photographs
Ramla (Gozo)
410.3
San Blas (Gozo)
91.4
Santa Marija (Comino)
101.2
Ramla tal-Mixquqa
215.6
Għajn Tuffieħa
275
Ġnejna
228.2
Bajja tal-Mellieħa
579.5
Ramla tal-Qortin
97.8
Armier
128.5
Little Armier
73.4
Ramla tat-Torri
136.1
Fomm ir-Riħ
82.1
72
Trends in the extent of beaches are based on expert judgement. In general, experts
deem that the extent of beaches has decreased199 as a result of development on the
coast and on land, affecting coastal erosion processes and sediment supply
respectively. These effects take place gradually over a long period of time and effects
of past developments are still being observed to date and are expected to continue
in the future. Given current environmental assessment processes, the expected
decrease in range/extent is more related to the long term effects of past
developments rather than future development, which effects cannot be addressed
at this stage. For this reason, sandy and shingle beaches are currently considered to
be of moderate status in terms of distribution/extent.
Assessment of habitat condition is based on records of species, of which presence is
indicative of a functioning beach ecosystem. Such species include Ophelia bicornis,
Tylos europaeus on sandy beaches, Tylos ponticus on gravel, pebble and cobble
beaches and talitrid amphipods. Expert judgement based on the presence/absence
of such indicator species indicates that four out of the selected beaches are
considered to be in good status; seven of moderate status and one of poor status.
Overall status in terms of habitat condition is also deemed to be moderate.
Shallow sublittoral rock and biogenic reef:
Assessment of status for shallow sublittoral rock focuses on photophilic algal
communities associated with bedrock within the 0-5m depth zone. This assessment
excludes specific geomorphological features forming part of the ‘shallow sublittoral
rock’ category, namely boulder shores, caves and overhangs, all of which generally
support sciaphilic algae as enclaves of deeper water communities. This is due to the
fact that data pertaining to the distribution of these geomorphological features is
limited, thus precluding the possibility to use such communities for assessment
purposes. Posidonia oceanica meadows growing on outcropping bedrock within the
6-45m depth zone are also being excluded from this assessment of status, since such
meadows are assessed separately as a ‘special’ habitat type listed in Annex I of the
Habitats Directive.
The currently available data pertaining to photophilic algae within the 0-5m depth
zone constitutes patchy snapshot data which presented difficulties in applying
current methodologies for assessment of status. Assessment was thus strongly based
on extrapolation of current data and expert judgement. Data was extrapolated on
the basis of the location of the 5m bathymetric contour, the presence of shallow
sublittoral sediment (hence absence of sublittoral rock), indication of the presence of
bedrock by Admiralty charts and habitat condition assessed for ‘Littoral Rock and
Biogenic Reefs’ (Figure 17).
199
This is a general statement and it should be noted that such decrease is not associated with all the selected
sandy beaches, some of which might have actually increased in extent – specifically Ramla (D.T. Stevens,
personal communication).
73
The use of data on littoral rock and biogenic reefs for extrapolation purposes is
justified in view of the similarities between the two habitat categories. Algal
communities within the 0-5m depth zone are also dominated by Cystoseira, albeit
belonging to different species than those characterising the littoral zone, and are
generally considered to be a continuation of the communities occupying the littoral
zone. Cystoseira species on both littoral and sublittoral rock are considered to be
indicators of good environmental quality, which in the 0-5m depth zone are replaced
by other algal species such as Pterocladia capillacea and Ulva laetevirens in disturbed
areas.
Based on actual and extrapolated data this habitat type covers circa 5km2 within the
0-5m depth zone (3.078km2 from available data and 1.921km2 from extrapolated
data). The only extent of this bedrock which is known to be altered due to
anthropogenic activities (also extrapolated from data on Littoral Rock) constitutes
less than 10% of the calculated extent. Status in terms of habitat condition is based
on the presence of Cystoseira species in the 0-5m depth zone as extrapolated from
the data on ‘Littoral Rock and biogenic reefs’, also coupled to expert judgement.
Overall, the status of shallow sublittoral rock based on the extrapolated data on
photophilic algae and expert judgement, is considered to be good.
Figure 17: Actual and extrapolated data on which assessment of shallow sublittoral rock was
based.
74
Shallow sublittoral sediment:
Assessment of status for shallow sublittoral sediment excludes Posidonia oceanica
meadows settled on sand or matte, since this habitat type is being assessed
separately as a special habitat type listed in Annex I of the Habitats Directive.
Shallow sublittoral sediment is characterised by different benthic communities, the
distribution of which depends on the varying sediment characteristics. The current
data scenario does not allow distinction amongst these communities, implying that
assessment of status for this predominant habitat type would reflect status of a
composite of benthic communities associated with different grades of sediment
ranging from mud to gravel. This composite also includes seagrass meadows
dominated by Cymodocea nodosa. This habitat type is considered to be very dynamic
in nature and determination of its distributional range and extent based on the
currently available snapshot data will not necessarily reflect its status.
Indeed, the information available for shallow sublittoral sediment in general is based
on localised and snapshot data. As for ‘Shallow sublittoral rock and biogenic reefs’
the current data was extrapolated on the basis of the presence of P. oceanica
meadows and bedrock, and the location of the 50m bathymetric contour.
Determination of the range and extent of shallow sublittoral sediment was thus
based on actual (12.3km2) and extrapolated data (38.1km2) (Figure 18). Based on
expert judgement, and in the knowledge of the fact that this habitat type is only
affected by localised pressures (such as aquaculture and recreational activities within
the innermost parts of bays), the extent of this habitat type is deemed to be in line
with the natural physiographic, and is thus considered to be of good status.
75
Figure 18: Actual and extrapolated data on which assessment of shallow sublittoral sediment
was based.
The determination of status for shallow sublittoral sediment in terms of habitat
condition (criterion 6.2) was based on the data generated on benthic invertebrates
as part of the current baseline monitoring of the EU Water Framework Directive200.
Through this monitoring, shallow sediments (mud, sand and gravel) were sampled
for the analysis of benthic invertebrates with a view to apply the AMBI index for softbottom macrofauna in accordance with Borja et al. (2000)201. This index is designed
to establish the ecological quality of coastal waters based on the response of softbottom communities to natural and anthropogenic induced changes in water quality.
The degree of impact is reflected by changes in the qualitative and quantitative
community composition.
The interim results of such monitoring indicate that all sampled stations can be
assigned to the ‘slightly disturbed’ category with the exception of one sampling
station along the coast of Gozo which can be assigned to the category ‘undisturbed’
and is used as a reference station. Only this station was assigned a ‘high’ ecological
status, while the rest of the stations are deemed to be in a ‘good ecological status’.
Four sampling stations which are currently being monitored are located in the Northeastern assessment area (Figure 19).
200
201
CIBM & Ambiente SC. 2012. Development of Environmental Monitoring Strategy and Environmental
Monitoring Baseline Surveys – Water Lot 3 – Surveys of Coastal Water – August 2012. ERDF156 - Developing
national environmental monitoring infrastructure and capacity
Borja, A.; Franco, J. & Pérez, V. 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-bottom
benthos within European Estuarine and Coastal Environments. Marine Pollution Bulletin 40 (12): 1100-1114.
76
The status of this habitat type is thus deemed to be overall good.
Figure 19: Stations assessed through the AMBI index as part of the WFD monitoring regime
Posidonia oceanica meadows:
The status of P. oceanica meadows has been assessed on different occasions in the
past twelve years. In 1995, a preliminary assessment based on the spatial and
bathymetric distribution, general health and plant morphological characteristics,
indicated that dense and healthy meadows cover large areas in inshore waters
although some regression was reported in areas subject to anthropogenic
pressures202. The 2007 Habitats Directive reporting assigns a favourable status to P.
oceanica (code 1120)203, which status was mainly based on expert judgement of the
benthic surveys carried out mostly in 2002. In 2009, a study which focused on
assessment of status of P. oceanica at four locations also indicated that the overall
state of health of Posidonia oceanica was good204.
202
203
204
Borg, J.A. & Schembri P.J. (1995): The state of Posidonia oceanica (L.) Delile meadows in the Maltese Islands
(Central Mediterranean); Rapp Comm Int Mer Medit 34 p123
http://cdr.eionet.europa.eu/mt/eu/n2000
Borg, J.A.; Rowden, A.A.; Attrill, M.J.; Schembri, P.J. and Jones, M.B. 2009 Occurrence and distribution of
different bed types of seagrass Posidonia oceanica around the Maltese Islands; Mediterranean Marine
Science 10(2); 45-61
77
Experts confirm that with the exception of localised areas in which Posidonia
oceanica meadows are known to have regressed as a result of anthropogenic
disturbance (mainly harbour areas), the current range and extent of P. oceanica are
in line with the physiographic and climatic conditions of the seabed. Within this
context, experts have confirmed that even when P. oceanica colonises areas outside
the current range and extent, such colonisation would not be viable, presumably
since natural conditions within such areas do not represent the required conditions
by the seagrass (J.A. Borg & P.J. Schembri, personal communication).
Posidonia oceanica constitutes a ‘Biological Quality Element’ which needs to be
assessed within the framework of the Water Framework Directive. The baseline
monitoring which is currently in progress for the purposes of the Water Framework
Directive205 is assessing the status of Posidonia oceanica meadows through the
application of the Rapid Easy Index (or PREI index) which was the method selected
through the intercalibration exercise for the Mediterranean region. This index is
based on the following attributes:
Shoot density
Shoot surface
Ratio between epiphytic biomass and leaf biomass;
Depth of the lower limit
Type of this limit (regressive, progressive or stable).
Reference conditions in this case referred to a ‘theoretical optimal site’ determined
on the basis of the second and third highest values for shoot density and shoot
surface area. The surveys were carried out in May and June 2012 in 10 sampling
stations, seven of which are interspersed within the north-eastern assessment area.
Based on the data collected and the methodologies outlined above the ecological
status of P. oceanica qualified as being of ‘high ecological status’ for three sites
within the north-eastern assessment areas and of ‘good ecological status’ for the
remaining two sites (Figure 20). These two sites are located off Sliema coast and
between Valletta and Marsaxlokk and are probably influenced by anthropogenic
activities206. This indicates that Posidonia meadows within this area can be
considered healthy and that habitat condition as per criteria is of good status.
It should be noted that the attributes used for assessment of status, are very similar
to the structural aspects defined for Posidonia oceanica by the Explanatory Notes
and Guidelines for assessment and reporting under Article 17 of the Habitats
Directive207. Therefore assessment of the habitat condition based on the PREI index
would also reflect the status of the ‘structure and functions’ as defined by the
Habitats Directive.
205
CIBM & Ambiente SC. 2012. Development of Environmental Monitoring Strategy and Environmental
Monitoring Baseline Surveys – Water Lot 3 – Surveys of Coastal Water – August 2012. ERDF156 - Developing
national environmental monitoring infrastructure and capacity
206
ditto
207
Assessment and reporting under Article 17 of the Habitats Directive: Explanatory Notes & Guidelines for the
period 2007-2012. Final Draft. April 2011.
78
Figure 20: Stations assessed through the PREI index as part of the WFD monitoring regime
Shelf sublittoral rock and biogenic reefs
The data available on shelf sublittoral rock and biogenic reefs is too limited to allow
any type of assessment of status. In general, it is presumed that waters at depths
greater than 50m are mainly characterised by sediment rather than rock, with the
latter only occupying localised areas within this depth zone (J.A. Borg & P.J.
Schembri, personal communication). However the location of such areas is not
known.
On the other hand, this type of habitat is probably not subject to significant
pressures from anthropogenic activities, hence even if the status cannot be
determined at this stage, such habitat type is expected to be in good status.
Shelf sublittoral sediment:
Assessment of shelf sublittoral sediment focuses on coarse sediments with
rhodoliths and maerl beds, the distinction between which depends on the
predominance of rhodoliths in the sediment. In maerl beds, rhodoliths constitute a
dominant component of the sediment, however there is no quantitative estimate of
79
rhodoliths which would distinguish between ‘sediment with rhodoliths’ and maerl
beds.
Localised data for this habitat type verifies the presence of a maerl bed off the
North-eastern coast of mainland Malta, covering an extent of the seabed of about
30km2 (this value is calculated from the extent of maerl bed as plotted in MEPA’s
data repository – published data indicates that the extent of this maerl bed is circa
20km2). Another 8.5km2 of seabed off the Southeastern coast of Malta is
characterised by both ‘sediment with rhodoliths’ and maerl. Based on this localised
data, coarse sediments with rhodoliths and maerl beds cover an area of about 40km2
within the North-eastern assessment area.
However, a recent survey of the seabed by Micallef et al. (2013)208 indicates a much
larger expanse of the seabed characterised by ‘maerl, sand and gravel’. Assuming
that this area constitutes an expanse of the seabed supporting various grades of
coarse sediments with rhodoliths ranging from sparse rhodoliths to maerl beds, this
habitat type would cover at least 77km2 of the north-eastern assessment area
(Figure 21). It should be acknowledged however that this value may also include
coarse sediments without rhodoliths. The distribution and extent of this habitat type
within the north-eastern assessment area needs further analysis, particularly to
verify the presence or otherwise of such habitat to the East of mainland Malta.
Assessment of status is completely based on expert judgement since the currently
available data does not lend itself to the application of standard methodologies for
determination of status on the basis of distributional range, extent and condition. On
the other hand, it should be noted that the experts involved in this assessment have
been studying the 30km2 maerl bed off the north-eastern coast of Malta, located
within the area of ‘Maerl, sand and gravel’ indicated by Micallef et al (2013)209, since
1996. Within this context, assessment of status focuses on the major maerl bed off
the north-eastern coast of the Maltese Islands, which is deemed to be in good status
in terms of range and extent. Such status can be extrapolated to cover the whole
extent of ‘Maerl, sand and gravel’ as indicated by Micallef et al. (2013).
Habitat condition has not been assessed at this stage. However given the low
pressures to which the major maerl bed off the north-eastern coast of the island is
subject to, status in terms of habitat condition is deemed to be good (in terms of the
extent of the seabed significantly affected by human activities)
208
209
Micallef, A.; Foglini, F.; LeBas, T.; Angeletti, L.; Maselli, V.; Pasuto, A. & Taviani, M. 2013. The submerged
paleolandscape of the Maltese Islands: Morphology, evolution and relation to Quaternary environmental
change. Marine Geology. 335: 129-147
ditto
80
Figure 21: Distribution of sediment with rhodoliths and maerl beds based on localised data
superimposed on the extent of ‘Maerl, Sand and Gravel’ as extracted from Micallef et al.
(2013)210
Upper Bathyal Rock and Biogenic Reefs:
Given the current data limitations with respect to upper bathyal rock and biogenic
reefs, it was not possible to assess status of this predominant habitat type for this
MSFD reporting cycle.
Upper Bathyal Sediment:
Given the current data limitations with respect to upper bathyal sediments, it was
not possible to assess status of this predominant habitat type for this MSFD
reporting cycle.
210
Micallef, A.; Foglini, F.; LeBas, T.; Angeletti, L.; Maselli, V.; Pasuto, A. & Taviani, M. 2013. The submerged
paleolandscape of the Maltese Islands: Morphology, evolution and relation to Quaternary environmental
change. Marine Geology. 335: 129-147
81
Table 10: Outcome of MSFD Initial Assessment of status for each predominant habitat type
Benthic Habitat
Littoral Rock
and Biogenic
Reef
Littoral
Sediment
Type of habitat
Cystoseira
communities
Assessment
Area
Criteria
North-eastern
Assessment
Area
Habitat
Distribution
(1.4)
Sandy and
Selected sandy
shingle beaches and shingle
beaches
Indicators
Distributional
Range (1.4.1)
Status
Good
Habitat Extent Habitat Area
(1.5)
(1.5.1)
Good
Habitat
Condition (1.6)
Good
Relative
abundance
and/or
biomass, as
appropriate
(1.6.2)
Overall Status
Habitat
Distribution
(1.4)
Habitat Extent
(1.5)
Habitat
Length of
coastline
Length of
coastline
Condition of
82
Good
Moderate
Moderate
Moderate
Assessment
Methodologies
Article 17
Guidance
document
(Habitats
Directive)
Article 17
Guidance
document
(Habitats
Directive)
CARLIT
Confidence Level
High
Low
High
Expertjudgement
Low
Expertjudgement
Expert-
Low
Low
Condition (1.6)
Shallow
sublittoral Rock
and Biogenic
Reef
Shallow
sublittoral
Sediment
Photophilic
Macroalgae
Shallow
sublittoral
sediment
North-eastern
Assessment
Area
North-eastern
Assessment
Area
judgement
the typical
species and
communities
(1.6.1)
Overall Status
Habitat
Distribution
(1.4)
Habitat Extent
(1.5)
Habitat
Condition (1.6)
Distributional
Range (1.4.2)
Habitat Area
(1.5.1)
Relative
abundance
and/or
biomass, as
appropriate
(1.6.2)
Overall Status
Habitat
Distribution
(1.4)
Habitat Extent
(1.5)
Condition
of
benthic
community
(6.2)
Distributional
Range (1.4.2)
Moderate
Good
Good
Good
Good
Good
Habitat Area
Good
(1.5.1)
Presence
of Good
particularly
sensitive
and/or tolerant
species (6.2.1)
83
Expert
judgement
Low
Expert
judgement
Extrapolated
from Littoral
Rock (CARLIT)
Low
Expert
judgement
Low
Expert
judgement
AMBI index
Low
Low
High
Special Habitat
Type
Shelf sublittoral
rock and
biogenic reef
Shelf sublittoral
sediment
Posidonia
oceanica
meadows
Predominant
habitat type
Sediment with
rhodoliths and
maerl beds
North-eastern
Assessment
Area
Overall Status
Habitat
Distribution
(1.4)
Habitat Extent
(1.5)
Habitat
Condition (1.6)
Expert
judgement
Moderate
Habitat
Area Good
Expert
(1.5.1)
judgement
Condition of
Good
PREI index
the typical
species and
communities
(1.6.1); Relative
abundance
and/or
biomass, as
appropriate
(1.6.2)
Overall Status
Good
Assessment of status was not possible due to the current state of information.
Moderate
North-eastern
Assessment
Area
Distributional
Range (1.4.2)
Good
Good
Habitat
Distribution
(1.4)
Habitat Extent
(1.5)
Physical
Damage,
84
High
Distributional
Range (1.4.2)
Good
Expert
judgement
Low
Habitat Area
(1.5.1)
Type,
abundance,
Good
Expert
judgement
Expert
judgement
Low
Good
Low
Upper Bathyal
Rock and
Biogenic Reefs
Upper Bathyal
Sediment
Coral
communities
Predominant
habitat type
having regard biomass and
to
substrate areal extent of
characteristics
biogenic
substrate
(6.1.1); Extent
of seabed
significantly
affected by
human
activities for
the different
substrate types
(6.1.2)
Overall Status
Good
Assessment of status was not possible due to the current state of information.
Assessment of status was not possible due to the current state of information.
85
1.6
Data Gaps and Further Work
The MSFD Initial Assessment identified significant data gaps with respect to the
distribution, extent and condition of benthic habitats. These data gaps are more
pronounced for benthic habitats associated with deeper waters, which data gaps
precluded the possibility for assessment of shelf and upper bathyal habitats.
Data gaps for benthic habitats associated with shallower waters pertain mainly to
trend data and information on the species associated with the habitat types, the
latter required for assessment of habitat condition. Due to limitations in trend data,
the MSFD Initial Assessment was mainly based on an aggregation of snap-shot data
collected throughout the past years as well as extrapolated data. Data on reference
conditions, as well as extent and nature of impacts, is also limited, as a result of
which this assessment was strongly based on expert-judgement.
The identified data gaps should be mainly addressed through a combination of new
monitoring programmes targeted at the requirements of the MSFD, adaptation of
existing monitoring programmes as well as marine research projects.
86