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

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same time ensure that we preserve current levels of n-3 highly unsaturated fatty acids (n-3 HUFA) in
farmed fish (Bell & Waarbo 2008).
Marine aquaculture requires a clean and unpolluted environment because it produces food for a
concerned and critical market, since the issues of food safety has, for the past decade, been on the
political agenda, particularly in industrialized countries (Olsen et al 2008). In this context, mariculture
production is completely incompatible with industrial pollution and also with pollution that originates
from mariculture activity itself. In several aspects, water quality is adversely affected by aerial
deposition of persistent pollutants, with little hope of recovery as can be seen with the example of
PCBs and other POPs.
Considering the above, site selection, therefore, is a central issue for the development of aquaculture.
Aquaculture, as any other human activity, influences and impacts the environment. Planning activities
for the development of aquaculture at a selected site inherently require some spatial analysis because
of the specific environmental and socio-economic aspects that would characterise the area. Therefore,
preliminary studies made beforehand to define a location as an optimal one for aquaculture must be
carried out. Such studies, dealing with site selection, can be developed at different spatial scales; at
the national level (hundreds of km), down to the regional level (tens of km) or even further down to
the local (km) level.
Site selection for aquaculture development has been worked out for several production systems such
as fish (Benetti et al., 2001), oysters (Chenon et al., 1992), mussels (Scout et al., 1998), clams (Arnold
et al., 2000), scallop (Halvorson, 1997), shrimp (Alarcon & Villanueva 2001) and seaweed (Brown et
al., 1999). The appropriate location of an aquaculture facility is one the most effective environmental
management tools available. Mistakes regarding to allocation of sites for aquaculture facilities can
produce conflict with marine environmental conservation and other user competing for space or water
quality.
Additionally, it is important to differentiate between site selection procedures for defining new sites in
pristine areas (development of aquaculture in pristine localities) and site selection within an area
already under production (new facilities within a region with aquaculture facilities). Also, because of
the lack of planning during the last decades for developing aquaculture, it may be necessary to
reallocate farms already under production to avoid environmental problems and/or social tensions. In
such a case, additional consideration should be taking into account, such as the capacity of recovery
of the ecosystem, the cost of reallocation and social cost for local population.
A spatial analysis for proper site selection should include the following aspects that are usually
considered for land facilities (Pillay, 1990; Kövári, 1984):
• land analysis: a general topographic appraisal and an assessment of drainage characteristics
and flood risks present at the site), and soil analysis;
• soil type: texture analysis and chemical analysis of major and minor nutrients;
• water analysis: water source characteristics, investigation of access to source water, chemical
analysis of major and minor elements plus heavy metals, dissolved oxygen, pH, temperature
and salinity.
• meteorological analysis: analysis of meteorological data from the region, with data on
seasonal patterns of rainfall and temperature, including disaster risk assessment
• traditional infrastructure analysis: analysis of site access, transportation networks,
logistics, export channels, communications networks, energy sources, labour pools and other
relevant infrastructure needs.
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