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Mediterranean Sea
case studies
VECTORS Fact sheet series
Vectors of change in European Marine
Ecosystems and their Environmental
and Socio-Economic Impacts
The VECTORS project seeks to develop
integrated, multidisciplinary research - based
understanding of changes taking place in our
marine environment, the mechanisms for
them and the ecological impacts expected
from them. VECTORS will examine how
these changes may affect the range of goods
and services provided by the oceans, the
ensuing socio - economic impacts and some
of the measures that could be developed to
reduce or adapt to these changes.
Western Mediterranean Sea
Sardinia case study: the Oristano gulf-lagoon
The main activities carried out along the coastal area of Sardinia, and in the
Oristano Gulf in particular, are maritime tourism and coastal fisheries. This
VECTORS case study is addressing a number of issues that tend to
generate conflicts in Mediterranean coastal areas. The San Marco
Peninsula, with the
Gulf of Oristano
on the right, the
Marine Protected
Area of Penisola
del Sinis – Isola di
Mal di Ventre (Sinis
MPA) on the left, and
the lagoon system
in the background.
Photograph: Sinis
MPA-Aeronike.
Regional Seas Case Studies
VECTORS studies three regional seas, the
North Sea, Baltic and Western Mediterranean,
as research areas for investigating the impacts
of human activities and how multiple pressures
can have combined and interacting effects
for the marine environment, society and
economy. Within each of the regional seas
several case studies are taking place to allow
more targeted investigation of the causes
and impacts of these pressures in particular
environments. This series of fact sheets
provides an overview of each case study and
the varying scientific approaches used.
In recent years, local fisheries have been subject to recurrent anoxic events
due to eutrophication caused by land-based discharges. This has lead
to mass fish mortalities with major financial consequences. The Oristano
gulf system is considered as being very sensitive to the effects of climate
change because of its shallow water and land discharges. Furthermore,
aquaculture practice, ballast water and global change together have
caused the spread of invasive benthic species which have found a suitable
environment in the area, thereby modifying the function of local benthic
assemblages. In addition, local MPAs are increasingly becoming a matter
of conflict between fisheries and tourism.
The western Sardinian Sea has also recently become the focus for potential
development of wind generating plans, generating a further potential
conflict of use between energy provision and tourism. This case study aims at addressing a number of environmental questions
related to evaluating the effect of predicted global changes on the
biogeochemistry and the biodiversity of the coastal zone, as well as
modelling the effect of climate change on coastal fish populations. In
terms of conservation strategies, the outcomes of this case study have
also provided scientific-based recommendations to the local authorities
in order to reinforce the management and conservation of biological
resources and habitats in the Gulf of Oristano.
Mediterranean Sea case studies
Drivers of change in the Mediterranean Sea
include eutrophication, fishing, tourism,
pollution, shipping and renewable energy
generation.
These activities can result in changes in
species distribution, impacts on biodiversity
and ecosystem function and a decrease in
fishing revenue, resources and tourism.
The fan mussel Pinna nobilis, exceeding one metre
in length, is the largest bivalve of the Mediterranean
Sea. This species is endemic to the Mediterranean
Sea, mainly living on soft sediments colonised
by seagrass meadows. In the past few decades,
P. nobilis populations have declined drastically
due to increasing anthropogenic pressure. Thus,
it was declared a protected species in 1992
(Barcelona Convention, Habitat Directive). The
recent enlargement of the Sinis MPA in the
area colonised by P. nobilis should contribute
to preserve both P. nobilis and the seagrass
meadows (P. oceanica and Cymodocea nodosa)
which constitute a refuge area for a large number
of species, increasing the local biodiversity.
Contact
Project coordinator: Mel Austen
Project manager: Jenny Lockett
VECTORS Project Office
VECTORS
V1: Feb 2013
Coordinated by Plymouth Marine Laboratory
[email protected], www.marine-vectors.eu
Why
The Oristano Gulf (OG) system represents a typical coastal area of the Mediterranean, with
its coastal lagoon system and shallow water bay. The OG system provides a test case
for addressing a number of issues that generate conflicts in Mediterranean coastal areas,
including:
The agricultural practice which is a direct cause of eutrophication of coastal areas and
lagoons because of the increased nutrient source and discharges that are in conflict
with fisheries and tourism.
Overfishing of lagoon areas which, together with anoxic events, have recurrently impacted
local resources putting them in conflict with preservation of natural resources and tourism.
Conflicts between tourism / Marine Protected Area (MPA) use and local fisheries in
relation to MPA management.
Other issues such as invasive species are starting to be of concern and will be
considered in this case study, in terms of fisheries and environmental quality.
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Top: traditional huts by the entrance of the lagoon. The inflow of fish is regulated by fishermen
through a system of screens. Bottom: Artisanal fishing of grey mullet in the diversion chamber.
Where
Sardinia is an autonomous region in Italy located in the NW Mediterranean sea dividing the
Algero-Provencal basin from the Tyrrhenian Sea. From an oceanographic standpoint, the
open ocean water circulation is strongly influenced by both the mesoscale eddies generated
along the northern edges of the Algerian currents and by the water exchange dynamics
occurring in the south along the Sicily Strait and Sardinian Channel. The Oristano gulf-lagoon
system (OG) is the widest shallow water area of the whole Sardinia island. More than six
lagoon systems are connected with the Gulf influencing the physical and trophic status of its
coastal waters. A wide variety of environments can be found, ranging from brackish water
coastal lakes, to choked lagoons, from hyperhaline shallow water areas to open sea areas.
Water circulation and temperature distribution in the Cabras lagoon and in the adjacent
Oristano Gulf coastal areas. Variations in water temperatures and hydrodynamic patterns
due to incoming climate changes will have strong consequences on the distribution
and abundances of the mullet, Mugil cephalus, in the Gulf – Lagoon systems.
How
VECTORS will address a number of relevant environmental questions are being addressed via a multidisciplinary approach
that involves experimental ecology, energetics, and numerical modelling. In particular, hydrodynamic and ecosystem
models as well as laboratory and experimental methods are being applied to the whole OG system in order to define the
main trends of changes of the coastal and lagoon ecosystems as a response to future climate change.
Specifically, focus has been directed towards investigating the following areas of study:
Evaluating the effect of predicted global changes on the main biogeochemical variables in coastal waters.
Estimating the impact of environmental variability on the distributional changes of biodiversity and food-web structure
with special reference to key species and invasive species.
Modelling the effect of environmental changes on coastal fish populations via a metabolic approach coupled with
oceanographic modelling.
Interacting with the main stakeholders and providing scientific-based recommendations to the local authorities and MPA
in order to reinforce the management and conservation of biological resources and habitats in the Gulf of Oristano.
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The future
The predicted IPCC climate scenarios foresee an increase of mean global temperature ranging between 2-3° to 4-5°in
the next 100 years with a consequent increase of the average seawater level. This potential scenario would have strong
consequences at both ecological and socio-economic scales for the coastal areas of Sardinia and the OG system in
particular. Because most of the southern part of the Gulf is characterised by low land areas, the risk of flooding will be high.
Furthermore, an increase of the sea water temperature and a change on seasonal sequences, could cause changes in
the abundance and distributions of benthic organisms in a warming scenario that would favour invasive species, and in
fish behaviour. In particular, those fish species which migrate from open sea to the lagoon’s systems following specific
temperature or salinity gradients could be forced to change their habits, with possible negative consequences for the
fisheries. Therefore, conservation measures will be particularly important for mitigating the negative effects of the climate
change on biodiversity and habitat sustainability for local species.
VECTORS
VECTORS is a European project (26455) supported within
Themes 2, 5, 6 and 7 of the European Commission
Seventh Framework Programme
Authors
The authors of this fact sheet are
Paolo Magni (CNR, Italy, [email protected]), Paolo
Domenici (CNR, Italy) and Andrea Cucco (CNR, Italy)