OPINION:Biological diversity can only be secured through an ecosystem-based approach to marine fisheries, writes Edward Fahy
REGULATING FISHERIES through catch quotas is, in theory, a simple exercise. The fish stock is assessed, its harvestable proportion (total allowable catch - TAC) is estimated and divided among those entitled to a share (quota). In practice, fish are valuable and there is an overwhelming temptation for fishermen to misreport what has been landed and where it has been caught.
Add to this the policy of EU ministers of fisheries to demand higher landings for their home industries than recommended by scientists and the casual enforcement of regulations, and you have the mess described by the European Commission in its 2009 statement of fishing opportunities: TACs are set too far above scientific advice to allow stocks to recover and, as a result, 88 per cent of EU fish stocks are overfished.
TAC/quota is not the only weapon in the arsenal of the Common Fisheries Policy (CFP), but it is the most important one. Its ambitions are, however, extremely limited: to regulate the harvest of a handful of "target" species in offshore waters.
The consequences of modern fishing are more extensive and damaging. The larger target fish are removed but the smaller ones are discarded, dead. Heavy modern trawling and dredging gears plough into the substratum and remove attached fauna and flora.
Discarding by-catch and fish waste alters the species composition of sea-bottom communities, which encourages the proliferation of scavenging species. Current fishing practice can create monocultures and it reduces biological diversity.
Leaving aside for a moment the unsustainability of a system which, in spite of considerable effort by scientists and managers continues to worsen, a lengthening list of international conventions relevant to the CFP are bringing pressure to bear on it. In addition, the Amsterdam Treaty makes sustainable development an explicit objective of the EU, while the Maastricht Treaty requires the integration of environmental protection into community policies.
The rationale and mechanism for an ecosystem-based approach by the CFP for a more sustainable and economically viable industry has been developed by, among others, David Symes and John G Pope in the UK.
The new policy would have a range of rules to protect habitats from damage by fishing gears; species additional to the target ones would be assessed for the effects of fishing; sea areas would be set aside as no-take zones, in which fishing would not take place and where the integrity of the marine community would be undisturbed; and an ecosystem impact assessment would be a necessary prelude to any harvesting activity.
The greatest obstacle to innovation is the inertia linked to the size of the fleet and the administrative infrastructure supporting it. The costly decommissioning of vessels and the removal of gear from existing fisheries had to precede more eco-friendly development.
However, the crisis provoked by the rising cost of fuel for an EU fishing fleet pursuing ever more depleted fish stocks will effectively put many vessels out of action, even if they have not been actually decommissioned.
Throughout the EU fishermen are despondent, and while there is sympathy for their plight, there is also a realisation that the inexorable and very rapid decline in the resource had to end in tears. What is required now, while the system continues to be managed along traditional lines, is to imaginatively introduce elements of an ecosystem-based approach in the space provided by the inevitable slowdown in fishing activity.
Dr Edward Fahy is a marine biologist. Prior to retirement, he worked for the Marine Institute as a team leader in the fishery science services division.