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

54 GFCM:XXXV/2011/Dma.9
5. Environmental criteria for site selection
by Pablo Sanchez Jerez
5.1 Main environmental challenges and bottlenecks for site selection and carrying capacity
Olsen et al (2008) have described the most important bottlenecks for further development of
aquaculture during the next decades. These may be categorized into three main clusters:
1. resource cluster (availability for resources such as space, feed and energy;
2. attitudinal cluster (public and consumer attitudes, legislation etc);
3. innovation cluster (new technology and market developments).
In the Mediterranean these clusters may also be regarded as the main bottlenecks for future
aquaculture development in general, although presently there are some Mediterranean peculiarities
affecting the significance of various components of these clusters. For instance, Mediterranean
mariculture is largely an exporting industry and therefore consumers tend to become interested in the
quality of product rather than in the impacts of the production system as, for example, is often the
case with salmon. Legislation is also quite variable among countries or even regions and there is,
therefore, no uniform effect of the state on aquaculture production, when making comparison. In
many countries there is lack of specific and well defined environmental quality standards related to
aquaculture. This deficiency has occasionally an effect on the environment but, more often, on
aquaculture since it leaves the industry vulnerable to sudden political decisions (e.g. orders to move
offshore at very short notice), not because standards are exceeded but because other uses of the
coastal zone have more political power than that of the relatively recently developed aquaculture.
Aquaculture is exposed to accusation of being a polluter of the coastal zone because it does produce a
certain amount of waste and it will probably continue to do so regardless of any progress in feed
technology, genetic improvement of the stocks, or farming practices. However, the release of wastes
(and particularly carbon, nitrogen and phosphorous compounds) does not necessarily cause pollution.
According to the GESAMP definition, pollution is the “Introduction of man, directly or indirectly, of
substances or energy into the marine environment (including estuaries) resulting in such deleterious
effects as harm to living resources, hazard to human health, hindrance to marine activities including
fishing, impairment of quality for use of sea-water, and reduction of amenities”. Therefore, pollution
needs to be defined in relation to agreed environmental standards beyond which action should be
taken. Although some fish farmers may think that postponing the adoption of such standards may
reduce pressures on the industry, it is probably to their benefit to have such an agreement with the
society.
Innovation is, of course, an important issue for all types of production, but so far Mediterranean
aquaculture has mainly followed the technological advances achieved in the salmon industry.
Therefore, issues like fish meal and fish oil replacement will probably follow the general solutions
that will become available for fish farming globally. It has been estimated (Bell & Waarbo 2008) that
by 2010, more than 85% of the fish oil and >50% of the fish meal will be consumed by aquaculture.
This is not an ecologically sound situation, and certainly it will not be sustainable in an overpopulated
world where food from the sea will be more and more costly. The problem becomes more serious
with the increased levels of polycyclic biphenyl compounds (PCBs) and other persistent organic
pollutants (POPs) found in European farmed salmon (Hites et al 1994), but also with Mediterranean
aquaculture species (Carubelli et al 2007). The bioaccumulation/biomagnification is more visible in
farmed carnivorous fish; this is because general contamination of the marine environment has
increased the levels of POPs, including in wild fish (Bayarri et al 2001; Cirillov et al 2009). In this
context, future strategies for aquaculture production must aim to reduce the current dependence on
fish oil and fish meal while taking all possible steps to reduce contaminant levels in fish and at the
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