Fish capture is imperfect. In the course of trying to harvest fish from the sea for which there is sufficient demand to make the effort worthwhile, fish are also caught which either are not in demand on the markets or should not be caught because their capture is against the goals of the administration responsible for management of the fish stocks. Much of this fish is discarded at sea. Efforts have and are being made to reduce the capture of this fish in the first place, through technical changes to fishing operations and through management measures to make their capture less likely. However, it is recognised that these measures are unlikely to ever eliminate discarding at sea altogether and another line of attack is to look at utilisation of these discards; in the words of the FAO Code of Conduct for Responsible Fisheries -
11.1.8.b) improve the use of by-catch to the extent that this is consistent with responsible fisheries management practices;
This paper firstly looks at what causes discards, their impacts at various levels and quantities and types of discards which have been documented. It then looks at measures that have and are being taken to use presently discarded fish with a view to assisting in identifying options for better use of fish resources throughout the world.
It became obvious, whilst reading and extracting information from the numerous reference materials consulted, that the way in which estimates of bycatch and discards has been conducted in many instances make it virtually impossible to draw firm conclusions that x tonnes of y species are caught as bycatch, discarded or utilised in a particular fishery or from a particular stock. The references generally either estimate the amount of bycatch caught in a particular fishery without endeavouring to quantify the amounts of various species in the bycatch or list the various species in the bycatch without estimating with any precision the amount of each species encountered. In most cases the species composition of the bycatch is merely quantified by referring to some species as dominant or most important rather than giving actual figures. Although there are some studies cited in this paper that endeavour to qualify AND quantify the occurrence of bycatch which is discarded and that which is retained for use, this information is such that, other than extract the raw data from the original source and present it here, no attempt is made to analyse the data further. The need for standardised methods for estimating bycatch and discards has been highlighted in a number of fora and until this is done information will generally remain fragmented and non comparable between fishing activities and make the estimation of bycatch in both terms of quantity and species extremely difficult and unreliable.
The study concludes that solutions are being found for the problems of discarding fish at sea and that in shrimp trawl fisheries in tropical regions particularly there are definite trends towards greater utilisation. The way and speed with which this evolution occurs depends very much on local conditions but can be stimulated by new utilisation opportunities identified through research and development in the areas of fish technology, market intelligence and exchange of information between different groups and regions.
In other fisheries where there is pressure on resources and threats to sustainable fishing activities the main thrust of development must continue to be the reduction of capture of potential discards.
The fact that fishing activities can lead to the capture of unsellable, unwanted and inedible products which are subsequently discarded dead or debilitated and not used for any useful purpose by man, has been long established. This can, not only constitute a loss of valuable food, but also have consequences for the environment, biodiversity and the living resources of the worlds seas. The capture of dolphin in tuna nets and turtles in shrimp trawls brought the problem to the foreground of public debate in the early years of this decade, but fisheries scientists, technologists and managers have been aware of problems in various forms and been looking at potential solutions for very much longer.
The main debate, however, over the security of food supplies and the sustainability of the world fishing operations is concerned, not with the capture of endangered species or those that capture the public imagination, but with the capture and discarding of species which could be used to feed people. This is linked to the biological effects that this fishing mortality might have on the sustainability of fish supplies from capture fisheries.
In 1994 FAO published Fisheries Technical Paper No 339 "A Global Assessment of Fisheries Bycatch and Discards" (Alverson et al 1994). The authors attempted to bring together the wealth of information from around the world on the magnitude of bycatch and discards, referring to over 800 papers containing quantitative and qualitative information on bycatch and discards in trying to characterise the nature and scope of the problem on a global and regional basis.
This technical paper and a number of international agreements recognise that there is a large amount of fish wasted for a number of reasons and call on those who exploit and manage marine fish resources to take a responsible attitude towards alleviating the problems that seem to be apparent.
The FAO Code of Conduct for Responsible Fisheries (FAO 1995) encourages nations to "establish principles and criteria for the elaboration and implementation of national policies for responsible conservation of fisheries resources and fisheries management and development".
In even clearer terms the Code of Conduct states the following:
8.4.5 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.
8.4.6 States should co-operate to develop and apply technologies, materials and operational methods that minimise the loss of fishing gear and the ghost fishing effects of lost and abandoned fishing gear.
8.4.8 Research on the environmental and social impacts of fishing gear and, in particular, on the impact of such gear on biodiversity and coastal fishing communities should be promoted.
11.1.8 States should encourage those involved in fish processing, distribution and marketing to:
a) reduce post-harvest losses and waste;
b) improve the use of by-catch to the extent that this is consistent with responsible fisheries management practices;
12.4 States should collect reliable and accurate data which are required to assess the status of fisheries and ecosystems, including data on bycatch, discards and waste. Where appropriate, this data should be provided, at an appropriate time and level of aggregation, to relevant States and sub-regional, regional and global fisheries organisations.
12.10 States should carry out studies on selectivity of fishing gear, the environmental impact of fishing gear on target species and on the behaviour of target and non-target species in relation to such fishing gear as an aid for management decisions and with a view to minimising non-utilised catches as well as safeguarding the biodiversity of ecosystems and the aquatic habitat.
The 95 states that met in Kyoto for the International Conference on the Sustainable Contribution of Fisheries to Food Security in December 1995 (Japanese Fisheries Agency 1995) endorsed the provisions of the FAO Code of Conduct and in Declaration 15 stated that, inter alia, they would "Promote fisheries through research and development aiming at : ........(iii) reduction of discard mortality; (iv) development and use of selective, environmentally safe and cost effective fishing gear and techniques;" This resulted in the following being included in the plan of action agreed at the Kyoto conference:
7. To increase efforts to estimate the quantity of fish, marine mammals, sea birds, sea turtles and other sea life which are incidentally caught and discarded in fishing operations; assess the effect on the populations or species; take action to minimise waste and discards through measures including, to the extent practicable, the development and use of selective, environmentally safe and cost effective fishing gear and techniques; and exchange information on methods and technologies to minimise waste and discards.
These documents reinforce the need to make sustainable and optimal use of the marine fish resources and agree that there are a number of lines of attack which are appropriate if the world is to continue to harvest and benefit from fish in the diet of human beings.
The expert consultations leading up to the adoption of the Code of Conduct for Responsible Fisheries and as recognised in the final document and the Kyoto Declaration, gave definite priority status to the avoidance of fish that might be subsequently discarded and only as a last resort to marketing and utilisation issues. The rationale behind this was that very often little is known about the effects of removal of the discards on the ecosystem and if a market for presently discarded fish is generated it is going to be difficult to reverse the situation.