Environmental Engineering Reference
In-Depth Information
advantages over capture fisheries. The global fishing industry has reacted slowly to
environmental imperatives - chief among these being the near-destruction of some
of the fish stocks that the industry depends on. This is because fishing typically
takes place in open-access or poorly policed waters where individual players have
an incentive to over-exploit a common resource with little regard to sustainability.
In contrast, most aquaculture operates in a setting where stock ownership and
farm sites are clearly defined. In economic terms this makes aquaculture a much
more efficient activity than fishing because farm owners have an incentive to invest
in the long-term viability of their operations, knowing that the benefits of good
management will not be dissipated by outsiders.
The Norwegian salmon industry provides some good examples of how aquacul-
ture can respond to environmental pressures. Furthermore, and somewhat counter-
intuitively, the evidence from Norway supports the idea that industry growth actually
has a positive relationship with environmental quality. Detrimental environmental
effects of aquaculture that are not accounted for in market prices are by defini-
tion externalities, and it is the internalisation of these externalities that explains
why some major environmental issues in aquaculture have been resolved. Data
from the early 1980s to the early 2000s show that, as their industry has expanded,
Norwegian salmon farmers have increased the degree of internalisation because of
negative feedback effects from pollutants (Asche & Tveteras 2006). The develop-
ment of more efficient feeds, largely attributable to feed makers, and the relocation
of cages away from protected inshore areas to areas with more suitable hydrology,
have cut pollution and associated disease problems. In 1980 it took almost 3 kg of
feed to produce 1 kg of salmon but by 2000 this amount had fallen to just over 1
kg. Over the same period, the use of chemicals and antibiotics in the Norwegian
salmon industry fell in absolute terms. Total antibiotic use peaked at nearly 50
tonnes in 1987 but, following the development of vaccines and the relocation of
farms, disease problems declined and antibiotic use dropped to around 1-2 tonnes
per year in the 2000s. These improvements came against a background of rising
annual output.
Not all parts of the world are as well regulated as Norway is, but the lessons there
show that the greatest environmental improvements do not rely on regulation, but on
the self-interested behaviour of individual operators and their suppliers in a broadly
coordinated industry. Negative environmental feedback will, particularly in a large
and expanding industry, prompt innovation and it should be the aim of voluntary
certification schemes to encourage the spread of innovation and best management
practices (BMPs) to accelerate positive change. Beyond BMP, where problems
may not be efficiently internalised because of weak feedback effects, certification
schemes provide a means to promote coordinated action and to reinforce existing
legislation aimed at addressing these more recalcitrant externalities. In the salmon
industry, problems associated with sea-lice and escaped salmon fall into this second
category.
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