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

56 GFCM:XXXV/2011/Dma.9
• fish farming infrastructure analysis: brood stock and fry suppliers, feed suppliers, fish
farming equipment suppliers and processing options that exist within the region
• market analysis: local and regional markets assessment and exporting opportunities to
foreign markets.
• government regulation and economic assessment: local and regional administrative,
political and socio economic conditions and regulations.
Because the complexity of coastal areas and marine ecosystems, site selection is one of the bottle
necks for sustainable and enduring progress. In coastal areas, the site selection analysis usually
requires data which are more complex to obtain; some of them also require complex collection
procedures. Therefore, for coastal farms, other considerations should be also taken into account:
• marine habitat mapping: distribution of marine habitats and information about their level of
legal protection and sensitivity to increase of organic pollution;
• oceanographic conditions and carrying capacity: current and wave analysis, profiles of
temperature and salinity, nutrients and chlorophyll levels;
• interaction with fisheries: fishery grounds and interactions with wild fish;
• negative impact from other users: sources of organic and chemical pollution and other risks
such as maritime transport activities and oil spills.
Site selection is closely related to carrying and holding capacity. Both these terms are usually used
indistinctively. However, carrying capacity of a defined area refers to the potential maximum
production of a species or population that can be maintained in relation to the available food and
environmental resources. Carrying capacity may be estimated for site selection in the case of filter
feeding organisms, such as mussels or clams. On the other hand, holding capacity is the potential
maximum production that is limited by a non-trophic resource, for example, the capacity of an
ecosystem to hold a determined biomass of fish. Holding capacity is closely related to other terms
such as assimilative capacity, production capacity or environmental capacity (Halide et al. 2009).
Site selection for aquaculture should take into account a series of basic requirements which are related
to the interests of the farmer but also to those of the society. These may be economic nature but also
of environmental economic or political (see Table 6).
Table 6 - Basic requirements for site selection and levels of compatibility with different site
characteristics
Type of
interest
Envir. / Econ
Requirements
Site Coastal Offshore Sheltered Exposed
High water quality for the farm
(dissolved oxygen levels) N Y N Y
Environmental Low effects on benthos N Y N Y
Environmental Low effects on the water column N Y N Y
Political Low competition level with other users N Y N Y
Economic Low investment cost Y N Y N
Social High safety for personnel Y N Y N
Economic Low risk of physical damage Y N Y N
Economic Low transport cost sites Y N Y/N Y/N
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