The discarding of bycatch has long been recognized as wasteful, although inevitable by virtue of the nature of fishing. It constitutes a loss of valuable food, has negative consequences for the environment and biodiversity and can be aesthetically offensive. Bycatch was propelled to the forefront of public debate in reaction to the incidental capture of dolphins in tuna purse seine nets, turtles in shrimp trawls and marine mammals, birds, turtles and fish in high seas squid driftnets. The outcome for all the fisheries concerned was dramatic, and not always perceived as rational from the viewpoint of fisheries interests.
An order of magnitude for the quantities of fish discarded was provided for the first time in an assessment published by FAO in 1994.1 Annual discards from the world's fisheries were estimated to range from 17.9 million to 39.5 million tonnes. A subsequent re-evaluation of these estimates, together with adjustments allowing for subsequent reductions in discarding, indicates that current levels are at the lower end of the range. The most recent FAO estimate of 20 million tonnes, if correct, is equivalent to 25 percent of the reported annual production from marine capture fisheries, which are those from which most of the discards derive.
In most respects, the decision by fishers to discard components of their catch is driven by economic factors. In an unregulated fishery, fishers have an incentive to discard if the expected net price, i.e. the real price less landing costs, is negative and if the resultant costs incurred in landing are greater than those incurred by discarding. Furthermore, there is an incentive to discard if the boat has a limited holding capacity. In such cases, fishers tend to discard the low-value components and retain those of higher value, a practice that is often referred to as "high grading".
Management involving the use of catch quotas commonly increases the incentive to discard. This is particularly so in mixed species fisheries where several of the species are subject to a quota. Three forms of discarding can be associated with quota management: the discarding of catch taken in excess of the quota, high grading and price dumping. The latter occurs where all or part of the catch of a species is discarded if a low price is expected. This could occur on the return journey to port, for example, when a fisher may decide to discard the day's catch so as to save the quota for a day when the price is higher.
Discarding is a feature of any management system that does provide for its specific and effective prohibition. In this event, there remains the issue of whether or not the added cost of enforcement is justified in lieu of the benefits and who should pay. In fact, most of the measures aimed at reducing the quantities being discarded carry substantial implementation costs. The rational argument that is gaining general acceptance is that the costs of implementation should be a cost against the fisheries and should therefore be borne - directly or indirectly - by those who clearly benefit directly from those fisheries.
The incentives to discard do not change with the introduction of licence limitation. Nevertheless, if the number of vessels is reduced as a result of licensing, there is likely to be at least a short-term increase in the stock of the bycatch species. Minimum size requirements would normally increase the discarding, particularly if enforcement is carried out at the point of landing. The benefit from enforcement at the point of capture - which is not always practical - is to "encourage" fishers to operate on grounds where there are fewer undersized fish and to employ more selective gears and practices.
Restrictions applied to the number of days at sea can lead to less discarding. This may occur simply as a consequence of reducing the fishing effort, in which case the effects are the same as those brought about by reducing the number of vessels. Additionally, there may be insufficient fishing time to enable the space to be filled with only the higher-value components of the catch, a situation that arises if storage space is limited. In such cases, more of the less valuable components could be retained and hence discarding could be reduced.
At the fishery level, the management measures that seek to reduce discarding fall into two broad categories. The first achieves lower quantities of bycatch through the use of more selective gears and practices, area and seasonal closures and increased bycatch utilization. The second category includes measures aimed at reducing the discarding of bycatch. These may be direct - such as when discarding is prohibited - or take the form of economic incentives to alter discarding behaviour.
The measures to reduce discarding in fisheries under quota management have gained increased prominence, as progressively more fisheries have been placed under ITQ management regimes. They include allowing above-quota catch to be traded - i.e. sold to those with unfilled quotas - as an alternative to discarding. Permissible levels of quota overrun allow fishers to exceed quotas in one year in return for a reduction in quotas for the following year. In New Zealand, permitted quota overruns are limited to 10 percent of the original quota for all species. Also in New Zealand, fishers can land species for which they do not hold a quota and record it against the quota held by other fishers. The voluntary surrender of above-quota catch without penalty is another option. In this event, the fisher may sell the catch in the normal manner, but must pay the "deemed" value (the value realized in excess of the cost of landing) to the management authority.
Norway has imposed a system where the discarding of quota species - including sizes that might otherwise have been discarded - is prohibited and all the catch is deducted from the quota. Individual fishers are responsible for ensuring that they have sufficient unfilled quotas to allow for any bycatch of quota species when targeting other quota species. They are also required to leave a fishing ground if there is a perceived risk of exceeding quotas or if there are abundant juveniles. This aspect of the Norwegian approach has provided a strong incentive to develop and apply more selective gears. In the United States, the North Pacific Fishery Management Council has resolved to prohibit the discarding of walleye pollock, Pacific cod, yellowfin sole and rock sole. This has commenced for the first two species and is to be phased in for the others over a five-year period.
The 1995 UN Agreement for the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks seeks to minimize pollution, waste, discards, catch by lost or abandoned gear and catch of non-target fish and non-fish species. This should be achieved, inter alia, through measures such as the development and use of selective, environmentally safe and cost-effective fishing gear and techniques. These obligations were reiterated with reference to all fisheries in the Plan of Action produced by the International Conference on the Sustainable Contribution of Fisheries to Food Security, held in Kyoto, Japan, in 1995.
The Code specifically states that: "States, with relevant groups from industry, should encourage the development and implementation of technologies and operational methods that reduce discards. The use of fishing gear and practices that lead to the discarding of catch should be discouraged and the use of fishing gear and practices that increase survival rates of escaping fish should be promoted." Where selective and environmentally safe fishing gear and practices are used, they should be recognized and accorded priority in establishing conservation and management measures for fisheries.
The Technical Consultation on the Reduction of Wastage in Fisheries2, held in Japan in October 1996, provided an important forum for a discussion of this issue by international specialists. The participants concluded that there had been significant reductions in discarding worldwide during the past decade. This had come about as a result of less fishing effort, time and area closures of fishing grounds, the use of more selective gears, the utilization of previously discarded bycatch, enforced prohibitions on discarding, and consumer-led actions. There were recommendations made with regard to information gathering, the future estimation of discards, options for fisheries management, the impacts on small-scale and recreational fisheries, gear selectivity and the utilization of bycatch.
The Inter-American Tropical Tuna Commission (IATTC) is continuing its substantial involvement in research on dolphin bycatches. The International Commission for the Conservation of Atlantic Tunas (ICCAT) is increasingly active with respect to the bycatch of sharks.
The process of resolving the bycatch and discards issue will be driven by forces at several levels. The community at large will continue to take offence, particularly where the problem is widely publicized and includes species with a high "aesthetic" value. The continued large-scale use of drift gillnets, for example, whether on the high seas or elsewhere, can be expected to remain a target of dissent. The substantial challenge for fisheries governance is to achieve balanced outcomes that are sensitive to community values but avoid unnecessary losses of benefit from the fisheries themselves. This will require the public to be correctly informed and those responsible for fisheries - including fisheries participants themselves - to establish credibility through continued efforts to reduce bycatch and discarding.
In the highly populous countries, particularly in Asia, where fisheries are characterized by many gears and several species in catches, relatively little of what is caught is not consumed or used as feed in aquaculture. Where wastage does occur, it is not so much the consequence of discarding but rather of some species - possibly many - generating more economic benefit when captured at a larger size. Where this can be established, the best management approaches are likely to include area and time closures and more selective gears. Nevertheless, this situation generally arises in countries where management is intrinsically difficult because fisheries often act as the employer of last resort. Improving the well-being of the fishers in one community would be a short-lived solution if there were a consequential inward movement of fishers from the surrounding communities.
1 FAO. 1994. A global assessment of fisheries bycatch and discards. FAO Fisheries Technical Paper No. 339. Rome.
2 I.J. Clucas and Dxc.G. James, eds. 1997. Papers presented at the Technical Consultation on Reduction of Wastage in Fisheries. Tokyo, 28 October-1 November 1996. FAO Fisheries Report No. 547, Suppl. Rome, FAO. 338 pp.