Site selection and carrying capacity in Mediterranean ... - FAO Sipam

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2.3 Effects on ecosystems, habitats and species
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GFCM:XXXV/2011/Dma.9
The European Environmental Agency (EEA) has defined (http://glossary.eea.europa.eu/);
different types of sensitive areas such as:
o Environmentally sensitive areas: areas of a country where special measures may be
given to protect the natural habitats which present a high level of vulnerability;
o Ecologically sensitive area: an area where it is likely that a change in some parts of
the system will produce a recognizable response, and
o Sensitive natural area: Terrestrial or aquatic area or other fragile natural setting
with unique or highly-valued environmental features.
These terms characterize various geographical sites, habitat types and ecosystems which may
be subject to a wide range of anthropogenic pressures and could also be protected by various
specific international conventions and agreements or by general management measures that
promote sustainable management of natural resources.
Huntington et al. (2006) have reviewed the potential effects of aquaculture on nature
conservation, focusing on a series of designations, i.e. Biogenetic reserves, Biosphere
reserves, Marine Protected Areas, Ramsar Sites, World /Heritage Sites, Natura 2000 sites
(Special Protected Areas (SPA) and Special Areas of Conservation (SAC), and Specially
Protected Areas of Mediterranean Importance (SPAMI). Based on an initial screening,
habitats included under the EU habitat Directive that are likely to be affected by aquaculture
were selected and assessed for sensitivity. A modified version of the Huntington et al. (2006)
analysis of the sensitivity of key habitats and species to various pressures from aquaculture
operations, but which is only focussed on ones that are of relevance to the Mediterranean
region are given in Table 2.
Of the habitats and species listed in Table 2, there is adequate documentation on the effects of
fish farming on seagrass meadows (Posidonia oceanica) and maerl beds in the Mediterranean.
Seagrass habitat
Posidonia oceanica is a slow-growing endemic seagrass species in the Mediterranean that
thrives in clear oligotrophic waters with high transparency (Holmer et al. 2003), provides
important ecosystem services such as shelter to juvenile stages of various marine species,
protects the coast against sediment erosion, and carried out carbon sequestration, thereby
helping to reduce CO2 levels in the atmosphere. Posidonia oceanica are known to be
considerably affected by fish farming (Diaz-Almela et al. 2008; Holmer et al. 2008,
Apostolaki et al. 2009, 2010), when the fish cages are sited close to the farm (