Download Development of Management Plans for the Conservation

Development of Management Plans for the Conservation & Management of Offshore Islets for the
Republic of Mauritius: Phase II
DEVELOPMENT OF MANAGEMENT PLANS FOR THE CONSERVATION AND MANAGEMENT OF
OFFSHORE ISLETS FOR THE REPUBLIC OF MAURITIUS – PHASE II
EXECUTIVE SUMMARY
1. The offshore islets are the last refuges of the biodiversity once found on Mauritius mainland,
which has been much more affected by the introduction of exotic species and predation. Today
less than 2% of Mauritius is under native forest, much of this has been degraded by the impact of
human activities and invasive alien species, and in most areas this degradation is continuing.
There is consensus that many of the islets have also undergone some form of degradation. Some
of the islets have been exploited variously under lease agreements with the State of Mauritius.
2. Conservation management and protection of the islets has suitable legal support and is
consistent with the national policy framework and the aims and purposes of International
Conventions signed by the State of Mauritius. If adequately enforced and implemented, these
legal and policy tools provide the basis for the protection, conservation, and restoration of the
islets. A full discussion of the legal and institutional issues can be found in the Strategic Plan
2004 of the Islets National Park.
3. In the past, the Government of Mauritius has commissioned various studies to consider the
potential for ecological restoration on the islets. The main examples include the following:
(i) the Wildlife Management International of New Zealand, whose report (1994) entitled “Mauritius
Offshore Island Survey Report and Management Plan” recommended the eradication of the
invasive alien animals and plants on some of the islets having high conservation potential,
(ii) the Islets National Park Task Force 2001, whose report highlighted that “many of the islets are
biologically very important and have great conservation potential due to their unique native flora
and fauna. Some still contain endemic species of flora and fauna, and others that have
undergone some degradation by human and animal interference still have the potential for
rehabilitation for preservation of native plant diversity”. The creation of the Islets National Park
consisting of 16 islets and a marine area up to 1 km around them under the aegis of the National
Parks and Conservation Service (NPCS) were also recommended,
(iii) In 2003-2004, under Phase I of the project the NPCS developed a strategic plan (the Islets
National Park Strategic Plan, 2004) for the following 16 islets: Flat Island, Gabriel Island, Pigeon
Rock, Gunner’s Quoin, Serpent Island, Ile d’Ambre, Round Island, Ile aux Fouquets, Ile aux
Mariannes, Vacoas Island, Ile de la Passe, Rocher des Oiseaux, Ile aux Fous, Ile aux
Flammants, Ile aux Oiseaux and Ile aux Aigrettes, with the assistance of AGRER, a consultant
company based in Belgium. Islet-specific biodiversity and conservation management schemes
were also drawn for only nine of the 16 islets.
4. This Phase II project was set out to develop management plans for the conservation of five
islets of the Islets National Park i.e. Flat Island and Gabriel island (north), Ile Mariannes, Rocher
des Oiseaux, and Ile aux Fous (south east), as well as two other islets in the south west which
had been recommended in the Task Force Report (2001) for recreation and tourism development
i.e. Ilot Fourneau and Ile aux Benitiers which in fact do not form part of the Islets National Park.
The immediate objective of this Phase II project was to prepare detailed five-year management
plans for the islets and associated lagoons based on biotope studies, covering the period (20092013) which would restore, conserve and sustain (including ecotourism) the natural biodiversity of
the flora and fauna of these islets. Such management plans would have to be in line with the
recommendations of the Islets National Park Strategic Plan (2004).
5. To address the issue of different parts of an islet having different conservation value, the
spatial zonation scheme (see below) based on biotope maps, important native species and fragile
habitats recommended in the Islets National Park Strategic Plan (2004) was used in this Phase II
study undertaken by a University of Mauritius consultant team.
Zones
Purpose
a
Protection Only
- Monitoring, protection and enforcement only
b
Restoration Only
- Conservation management only
c
Limited Public Access 1
d
Limited Public Access 2
e
Recreation
-
Eco-tourism and scientific research, conservation
management
-
Education and public awareness, conservation
management
-
Mainly recreation
6. Terrestrial ecological surveys were carried out by the consultants to determine the existing
environmental conditions and to document the native and alien flora and fauna present at the
study sites. The following were surveyed: habitat/vegetation types, flora (angiosperms and
pteridophytes), vertebrate fauna (mammals, birds and reptiles) and indicator groups of
invertebrate fauna (butterflies and non-marine mollusc). Sampling for identification and
assessment was undertaken along radial transects using GPS to enable transitions to be
identified for biotope demarcation and mapping. (Note: the radial transect sampling takes into
account the effect of windward/leeward aspects of biodiversity distribution). Biotope mapping
was undertaken using aerial photography and GPS positioning incorporated in GIS.
7. Resulting outputs of the terrestrial ecological surveys included (a) GPS based biotope maps
characterizing the native/endemic content, (b) distribution maps of threatened species, (c) GIS
overlay biotope maps with coverages generated for islet feature evaluations, (d) identification of
distance to restoration target (expressed in terms of time, finance and native to invasive alien
abundance ratio, (e) zonation map of each islet, and (f) environmental impact assessments
(EIAs) and identification of management constraints/risks.
8. Marine surveys for natural biodiversity utilized the ‘Quick Site Survey’ (QSS) method to collect
data on the spatial distribution and variability of the sub-tidal benthic biotope types within the one
kilometre buffer zones adjacent to the target islets. The QSS method has been successfully used
for habitat mapping as well as for collecting data for calibrating satellite images and validating
biotope maps (e.g. accuracy assessment). The marine areas surrounding the islets were
surveyed with respect to the effects of prevailing winds and water currents on the benthos. A
system of radial transects extending to 1 km offshore from each islet or group thereof was
adopted. A Global Positioning System was used to record each point. Observations were
standardized (i.e. the key biota and habitat structure were grouped into common types for ease of
applicability at all study sites). Photographs were taken to provide a visual record and descriptor
of the habitat type being described and for reference in future surveys. Such technique allows the
maps of biotic cover to be more easily interpreted. The data collected from the QSS were loaded
onto MapInfo software for creating a GIS file and used for identifying the different biotopes and
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their distribution within the survey areas. These data were then compiled to create the habitat
maps for each islet or islet grouping.
9. For management purposes, the biotope classifications were examined to generate “zonations”
of the islets or islet groupings, using the scheme presented at (5) above.
10. In this study, the Ecosystem Approach was adopted for proposing islet management.
Ecosystem approaches to management involve a holistic, ecological view of natural resources and
the environment. They recognize that human activity takes place within, and not outside of,
ecosystems. More justification for this approach lies in the principles of biodiversity conservation
agreed at the September 2002 Johannesburg WSSD (namely the application of ecosystem based
biodiversity and natural resource management), in the recommendation of the Islets National Park
Strategic Plan 2004 (namely on the need to integrate the Islet National Park into a broad-based
integrated coastal zone development strategy), and in the terms of reference of this project.
11. The islets under study are considered as belonging to the following systems, and broadly their
management plans are proposed accordingly in this report:
(1) Flat and Gabriel Islands, the lagoon and offshore waters including Pigeon Rock - in this
study referred to as the Flat -Gabriel Island System/Complex)
(2) Ile Mariannes, Rocher des Oiseaux and Ile aux Fous (Mahebourg Bay) - in this study
referred to as the Ile Mariannes-Rocher-Fous System/Complex)
(3) Ile aux Benitiers and Ilot Fourneau (south west) - in this study referred to as the Ile aux
Benitiers – Fourneau System/Complex.
12. Differences in species-specific conservation opportunities between the islets, however, are
notable and these are accommodated to the maximum feasible extent through zonation and
island-specific management prescriptions. However, it is important to recognise that speciesspecific approaches to conservation often create unforeseen outcomes as ecological space is filled
and vacated as a consequence of management actions, urging careful consideration in how
simple, but fragile, systems are managed. A long history of native species demise in the face of
alien predators that were introduced as a means of regulating alien pests attests to the risks
attached in ‘over-manipulating’ ecosystems with the sole task of regulating single species
populations.
13. A stakeholder questionnaire and subsequent workshop provided considerable guidance in
identifying the most critical issues weighing on the future management of the islet complexes and
these have been given every consideration in the final drafting of this plan. A number of these cut
across the planning framework and garnered broad support among groups with staggered
interests. These have been flagged for consideration, as a matter of priority by the conservation
management consultants.
14 The management plans for all the islet systems have adopted the structure established during
Phase I of islet management planning in order to maintain continuity and ease future integration of
individual management as outlined in the Islets National Park Strategic Plan 2004. Zonation and
biotope maps follow schemes established in the Strategic Plan and build upon recommendations
made by the Islets Task Force Report (2001) and stakeholder consultations.
15. Flat-Gabriel Island Terrestrial System: Very brief plans drafted for Pigeon (House) Rock
under the previous phase (2004) are also rolled up into the management plan of the Flat- Gabriel
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Island system. These three islands clearly have a shared terrestrial and marine history due to
their spatial proximity. Modern trends in resource use and the shared pressures, threats and
vulnerabilities continue to point to the area as a single ecosystem complex. Implementation and
coordination of management activities, including enforcement, through a single management plan
(and authority) will improve cost-effectiveness of deployed measures. Consequently, a single
management plan has been developed for both Flat and Gabriel islands (with full protection
assigned to Pigeon Rock).
The 296 ha Flat and Gabriel Island Complex, including Pigeon House Rock, contains a diverse
assemblage of more than 125 plant and 19 vertebrate taxa, including important populations of
three endemic skink, two gecko and four vascular plant species that are known from only a few
other locations worldwide. Flat and Gabriel Islands have a long history of land use dating back to
the 18th century. Successive use of the island since then, particularly Flat Island, has led to
significant changes to the natural ecosystem, most notably in the establishment and spread of
woody plants, grasses and colonization by a number of alien mammal and reptile species. Alien
plants, which account for nearly 60% of the known flora, cover 70% of Flat Island, represented by
five of ten biotopes. This dominance is reversed on Gabriel Island where native plants account
for 45% of the cover and are represented by six of eight biotopes. Successful bait trap
campaigns in 1995 and 1998 have led to the eradication of rodent mammals from both islands,
opening up opportunities for ecosystem restoration.
Lease of the islets in 2007 with a view to privatising and expanding existing use of the area as a
day-trip tourist destination presents a number of opportunities and challenges in management
over the five-year period. Careful and appropriately-designed restoration of select historical
buildings and infrastructure and tourist facilities could increase visitor experience while avoiding
significant ecosystem degradation. Opportunities for expanding use to allow greater education
and nature-based activities exist with careful investment in management infrastructure and
establishing a cap on daily visitor numbers. A daily cap should be based on estimated carrying
capacity of the lagoon-strand system. Sustainable use of the islands rests with overcoming
challenges through (1) effective management of solid waste, (2) installation of quarantine
protocols and facilities on the islands to prevent further invasion by alien plant and animals, (3)
management of the strand-beach-lagoon system to minimize visitor impact and maintain safety
and (4) implementation of ecosystem restoration activities. A number of specific management
activities have been prescribed for implementation over the cycle to both further advance
opportunities and meet existing management challenges.
Management of the Flat-Gabriel Island Complex is framed as a continuous process consisting of
consecutive cycles of implementation, review and planning.
Administration of management
cycles now under the remit of the National Parks and Conservation Service (NPCS) should fall
under the responsibility of a specialized authority on biodiversity (i.e. a National Biodiversity
Institute – NBI). Implementation of activities should be undertaken by staff of the lessee/s and
the NBI.
Monitoring of management success is structured through an oversight committee
consisting of relevant public and private sector representatives. Operational management
activities are to be reported to this committee quarterly with a strategic review submitted annually.
Both quarterly and annual meetings should afford opportunity to adapt management priorities and
timeframes where monitoring of prescribed activities suggests undesirable outcomes, or new
challenges present themselves and require alternate actions. An end-of-cycle review should be
undertaken with participation by the broader public and private communities in order to adapt
each subsequent management plan to changing challenges and opportunities brought about
through the prior cycle outcomes and extrinsic influences shaping management direction, such as
climate change, natural catastrophes or strong public sentiment.
16. Ile Mariannes Terrestrial System: Ile Mariannes is designated as a Nature Reserve under
the Forests and Reserves Act 1983. Its associates, Ile aux Fous and Rocher des Oiseaux are
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designated as Islet National Parks (Government Gazette 50 of 29 May 2004, Proclamations 20
and 15) and are recommended in the Islets National Park Strategic Plan (2004) to be managed
as Closed Reserves just as for Ile Mariannes. These islets are in close proximity and were once a
single island. Consequently, they are treated here as a single entity and Ile aux Fous and Rocher
des Oiseaux should certainly have the access status currently enjoyed by Ile Mariannes.
The 2 ha Mariannes Islet Complex in Mahebourg Bay consists of a main islet (Ile Mariannes) and
two smaller bare rock formations, Rocher des Oiseaux and Ile aux Fous. Their small size and
proximity to the fringing reef limit the number and type of plant and animals found on the islets.
The plant community consists of twenty nine vascular plants bundled into eight biotopes.
Biotopes are strongly stratified in relation to windward/leeward position, but most consist of native
species. Native plants account for more than 90% of plant cover that also account for nearly 60%
of the taxa recorded, principally from the largest islet, Ile Mariannes. The islet complex fauna is
largely invertebrate, with only a few seabirds known to use the area as a roosting site. Both
mammals and reptiles are absent. Levels of standing herbivory on the islet combined with
observations of invertebrate populations of phytophagous insects ancecdotally indicate that the
trophic structure may be missing a top predator.
All three islets fall under the stewardship of the Ministry of Agro-Industry, Food Production &
Security. Ile Mariannes is a declared Nature Reserve and is administrated by the Forestry
Service. Rocher des Oiseaux and Ile aux Fous have recently been proclaimed National Parks
and fall under the responsibility of the NPCS. While the de jure status of the islets separates
administrative responsibility, there is a need to align de facto operational management under the
umbrella of a single authority. One option is to outsource operations to a third-party capable and
willing to manage the islets towards the management objective of ecosystem protection and
conservation. However, administration of management cycles should fall under the remit of the
National Biodiversity Institute.
Operational management of the Mariannes Islet Complex consists primarily of protective
measures, such as signage and improved monitoring and enforcement, with some additional
conservation activities aimed at eliminating a small community of alien plants from Ile Mariannes
and exploring prospects for (re-)introduction of a skink population.
Monitoring of management success is structured through a broader Mahebourg Islets oversight
committee consisting of relevant public and private sector representatives. Operational
management activities are to be reported to this committee quarterly with a strategic review
submitted annually. Both quarterly and annual meetings should afford opportunity to adapt
management priorities and timeframes where monitoring of prescribed activities suggests
undesirable outcomes, or new challenges present themselves and require alternate actions. An
end-of-cycle review should be undertaken with participation by the broader public and private
communities in order to adapt each subsequent management plan to changing challenges and
opportunities brought about through the prior cycle outcomes and extrinsic influences shaping
management direction, such as climate change, natural catastrophes or strong public sentiment.
17. IIle aux Benitiers-Fourneau Terrestrial System: Separate terrestrial management plans
are presented for Îlot Fourneau and Ile aux Benitiers. Ilot Fourneau is an undesignated islet
currently under the stewardship of the Ministry of Housing & Lands following an expired lease
agreement (1962-1992) for agriculture. The islet is in close proximity to the mainland and the
small fishing hamlet of Le Morne. It is currently under frequent use for local fishing and sea
cucumber collecting, as well as wood collecting, intermittent farming and shellfish processing.
Ile aux Bénitiers is under the responsibility of the Ministry of Housing & Lands but currently under
a lease agreement for industrial/ecotourism development potentially until 2050. The islet is in
close proximity to the mainland village of La Gaulette and several highly rated, luxury hotel
complexes located on the Le Morne Brabant peninsula. It is currently under frequent use by local
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tour operators bringing overseas and domestic day-visitors to the western beach line. It is also
regularly used as a base for local fishing and sea cucumber collecting, as well as wood collecting,
intermittent farming and shellfish processing.
Ilot Fourneau: Located less than 500m from the mainland, the steep topography of the 12.6 ha
Ilot Fourneau yields a variety of edaphic conditions under a relatively uniform vegetative cover.
With 109 recorded vascular plant species, the islet contains one of the most speciose floras
among the offshore islets.
Four of the nine biotopes on the islet are characterized by invasive
species, and these account for 80-90% of plant cover. The dominance of alien plants on the islet
belie the relative richness of native plants that account for half of the total plants recorded,
including eight species endemic to Mauritius. The vertebrate fauna is largely alien in origin, apart
from a healthy population of ornate day geckos. In contrast, the islet contains one of the richest
native gastropod and lepidopteran communities known from offshore islets.
The islet is undesignated State Land under the administrative stewardship of the Ministry of
Housing & Lands. The area was leased for agricultural use until 1992 and is currently unleased.
The islet also falls within the recently designated Le Morne Cultural Landscape (LMCL) and
would form part of the larger management buffer zone surrounding the Le Morne Mountain under
the World Heritage Site classification. The large number of endemic plants and invertebrates,
juxtaposition to Le Morne and general management provisions under the LMCL plan argue in
favour of inclusion of Ilot Fourneau under the management framework afforded through the
broader LMCL.
The status of Open Lease State Land is recommended for the islet as it can prospectively be
utilized for a range of purposes. Management activities identified for Ilot Fourneau are however
largely consistent with those established for the broader LMCL, including restoration and
conservation of native communities, biological and anthropo-archaeological research and lagoon
fisheries management. Monitoring of management success should be coincident with that
established for broader monitoring structures established for the LMCL, but with specific reporting
structure concomitantly in line with that established for other offshore islets.
Ile aux Benitiers: Located north of Le Morne Brabant, the 65 ha area of Ile aux Benetiers is
distributed over a very restricted elevational range consistent with its sedimentary substrate.
With 90 known vascular plant species, the islet has a diverse flora largely dominated by alien
plants (61% of known taxa) but with large populations of a number of notable native and endemic
species. The largest Mauritian/Mascarene populations of three of these species are situated on
the islet. While fewer native plants contribute to the total species richness on the islet, they
account for the lion’s share of plant cover, estimated at 50-60%. This cover is largely attached to
the four of seven biotopes characterized by relatively high abundances of native plants. The islet
is home to an important population of the endemic Pic-Pic and a number of migratory birds
seasonally forage the northern sandy shoals and beaches. Two endemic day gecko populations
are known from the islet, but the vertebrate fauna is otherwise dominated by alien mammals and
reptiles. Lepidopteran fauna is notably rich in native species.
The islet is undesignated State Land under the administrative stewardship of the Ministry of
Housing & Lands. The area has been continuously leased for agricultural use since 1933. The
current lease is due to expire in 2010 (renewable at the Lessee`s option until 2050).
Unmanaged day-trip tourism is the largest and most active use of the islet. Lease of the islet as
State Land places de jure managerial responsibility in the hands of the lessee on the basis of an
approved industrial use of the islet. However, management of recreational activities on the islet is
currently non-existent. Consequently, the impacts of increasing day visits continue unabated with
no investment made in facility development, and management that is needed to mitigate impacts
of increased visitor use and to promote effective habitat restoration.
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Plans by the lessee for further development of the islet as a hotel complex require careful
integration of prescribed protection and conservation measures attached to north and south
zones with appropriately designed, engineered and managed facilities that will not lead to notable
degradation of terrestrial and surrounding lagoonal environments. Opportunities to develop a
successful public-private partnership that can deliver both environmental and economic benefits
are significant, assuming genuine effort to mitigate impacts and investment in islet management.
A number of these investments would improve conservation zone quality through selective
actions aimed at increasing native to alien species abundance ratios and protecting important
lagoonal seagrass beds. The islet is particularly vulnerable to sea level rise and erosion by the
nature of its sedimentary substrate.
Monitoring of management success is essential to ensure any conservation-recreation outcome
remains balanced and progressive. A Technical Advisory Committee (TAC) consisting of public
sector agencies and NGOS should provide half-yearly review of on-going site management with
the lessee acting as the coordinating body for convening of TAC meetings and production of
required reports and records.
18. Flat-Gabriel Island Marine System: A single marine management plan is recommended
for the Flat-Gabriel Island System. A Marine Protected Area with the status of Marine Reserve is
recommended for the marine space adjacent to Flat and Gabriel Islands out to the 20 m isobath
including the lagoon between them. The lagoon has very rich biodiversity and is under
considerable pressure from recreation and tourism. A zonation scheme has been proposed,
which, if implemented, would both enable tourism activities to be regulated and the marine
environment to be protected. No additional operators` licences should be issued before a full
carrying capacity study of the Flat-Gabriel Island System is carried out. Currently it cannot be
ascertained whether the limit has already been exceeded, in which case the number of visitors
should be reduced or methods for better management of the visitors should be investigated.
19. Ile Mariannes Marine System: The marine environment of Ile Mariannes System is
recommended to remain undesignated and no MPA is proposed. This stand is based on the low
ecological value of the marine habitats around the islets and also due to the difficulties (financial
and otherwise) of policing such zone for conservation. On the other hand, given the proximity of
these islets to the coral reef, the area is a popular ground for artisanal fishing.
20. Ile aux Benitiers-Fourneau Marine System: The lagoon around Ile aux Benitiers is under
considerable pressure from tourism and that around Ilot Fourneau is starting to come under
pressure, primarily from sports activities such as wind and kite surfing. The seagrass beds around
both islets are of great ecological importance and significance but are under constant threat of
degradation. These habitats should therefore be protected. The zone extending from the north of
Ile aux Benitiers around Le Morne to the east of Ilot Fourneau and out to the 20 m isobath is
recommended for designation as a Marine Protected Area. Such designation will assume even
higher importance for ecosystem management when considered in the context of the designated
Le Morne World Heritage Site and the existing Black River Gorges National Park. The declaration
of the Le Morne World Heritage Site will no doubt increase tourism pressure in the lagoon space
around both Ilot Fourneau and Ile aux Benitiers. This calls for the immediate determination of
carrying capacity of these islets to safely support any tourism development, especially with the
designation of the proposed MPA.
21. To ensure effective protection, conservation and safeguard of biodiversity on and around the
islets, enforcement of existing law and consolidation of management of all protected areas, both
marine and terrestrial, under the aegis of one single institution (e.g. a National Biodiversity
Institute) would be necessary. The continued split responsibilities for biodiversity management by
several institutions can only be detrimental to the nation because this results in an ineffective and
deficient management, hence unsustainable.
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22. A dedicated enforcement service, such as an Islets National Park Ranger Service under the
National Biodiversity Institute would ensure accountability for performance (to be monitored
adequately by an annual evaluation process). The National Coast Guard is considered highly
inadequate for the tasks at hand because the duties of a National Coast Guard Officer are very
varied. The duties of an Islets National Park Ranger would be confined to the management areas
targeted i.e on and around the islets specifically. The endeavour of the proposed Islets
National Park Ranger Service would also be scientific rather than merely policing. Rangers
would require very specific training relevant to the management of the Islets National Park to
foster co-management of islet resources with relevant stakeholders. The proposed National
Biodiversity Institute would rather be under the responsibility/jurisdiction of the Prime Minister`s
Office for better efficacy of biodiversity conservation in the Republic of Mauritius.
23. The Islets National Park Strategic Plan (2004) recommended carrying capacities (maximum
allowable numbers of visitors at any one time, determined by the Delphi technique) for various
islets including Flat and Gabriel Islands. The estimates based on biodiversity and cultural values
as well as cultural integrity were 300 for Flat Island and 160 for Gabriel Island. This study
recommends that an estimate of the maximum Tourism Carrying Capacity (TCC) will have to be
determined by the limits of acceptable change (LAC) applied to the Flat-Gabriel Island System as
well as the Fourneau-Benitiers System, and maintenance of visitor experience. These in effect
will frame the sustainability of use and thus the prospects for indefinite use. Chronically
exceeding the maximum TCC invariably will degrade the natural environment, reducing visitor
experience and inter alia, their willingness-to-pay for the privilege of experiencing the natural
environment offered by these islets.
24. Resource Centres should be established on the Flat - Gabriel Island system and Ile aux
Benitiers to provide (a) visitors with ecological and historical/cultural information about the islets
and the surrounding areas, (b) a base for education, research and scientific monitoring and (c) a
base for activities of the Park Rangers and to police the targeted areas.
25. To foster effective biodiversity conservation will no doubt require societal change in attitudes
which can be initiated and best attained through the national educational curricula and aggressive
public sensitisation campaigns.
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