There have been schemes in various shrimp fisheries in tropical less developed countries to encourage fishermen to land more of the bycatch. The reasoning in these cases has normally been to make available animal protein, which was being dumped at sea, to a protein deficient population.
One of the earliest examples documented was a scheme started in the 1970s by the government of Guyana which required all trawlers to land one tonne of bycatch for each fishing trip, in return for an exemption from export taxation and a nominal payment from the government (Gordon 1981). The rationale behind this initiative was to make use of locally available raw material, reduce dependence on imports of fishery products and increase availability of fish on the local markets. The simple act of requiring some bycatch to be landed did not mean that fish was being utilised and recognising that the species and the types of fish landed as bycatch would not necessarily be immediately acceptable, an extensive government initiative aimed at the expansion of processing and marketing opportunities for the fish was begun. This involved investment in an integrated fish processing facility with a capacity of up to 50 tonnes per day which amongst other options included the ability to produce individually quick frozen fish, frozen blocks of fish, minced fish products canned products, smoked fish, salted and dried fish and a means of producing fish meal from offal and waste. (Petersen 1981) The investment was made following the successful marketing of products from bycatch on the Guyanese markets, and specifically for fish products already known on the market, through a preliminary phase of experimentation and market testing.
The Guyanese experience has been followed by a number of examples outlined above of use of bycatch from shrimp fisheries showing that there are possibilities for fuller use of the resource, but that each location and each set of circumstances require different solutions. Experience has shown that similarities in raw material supply in different parts of the world, does not necessarily mean similarity of solution. The feasibility of producing commercially acceptable product from shrimp bycatch depends more on market forces and socio-economic conditions than the ability to make products from the raw material. The general trends by region seem to be as follows:
East Asia (China) - Animal and aquaculture feeds
S E Asia - Value addition, novel foods
S Asia - Fresh fish, traditional products and animal feeds
E Africa - Production of traditional products (dried fish)
W Africa - Sold on beaches as fresh fish to various traders into normal fish trade
Latin America - Fresh fish, novel products and animal feeds
One of the main factors which governs the amount of fish from the bycatch which is used is the length of fishing trips. The shorter the trip the more likely that bycatch will be landed. The development of at sea collection systems has and is overcoming this constraint to utilisation in a number of instances in different parts of the world.
In China production of fresh water fish such as carps and tilapia, crabs and shrimp have increased very much in recent years (FAO 1996d) adding to the demand for cheap sources of animal/fish protein. It is suggested that because of this huge demand for animal protein little of any of the bycatch from the nations fishing operations is now discarded at sea. (Zhou Y and Yimin Y 1996)
In South East Asia there has been a trend towards the use of particular species selected from the catch for the production of value added and specialised (sometimes innovative) products. In South Asia the trend as been towards the selection of specimens that would already have a market either as fresh fish or into traditional products such as dried fish with the remainder of the catch being used for the production of animal feeds of fertilisers.
FAO (1996) estimate that in Sub Saharan African shrimp fisheries "only 10 to 15 percent of an estimated bycatch of about 1 million tonnes is landed" It is noted however that there is a trend towards better utilisation of bycatch through the introduction of specific regulations and the development of collection at sea systems.
An FAO workshop held in Cuba in 1997 brought together representatives from a number of Central and South American countries to review the bycatch utilisation systems in the respective countries. The meeting concluded that the amount of non shrimp caught was still high (between 90 and 97% of the total catch) but that utilisation of the bycatch has increased. On the Pacific coast of Central American it was estimated that between 40 and 60% of the bycatch is used and a similar situation exists on the Atlantic seaboard except in Nicaragua, Honduras and Suriname where small lack of demand and infrastructure mean that only between 20 and 30% of the bycatch is used. The workshop concluded that generally the bycatch consisted of 30% commercial species (which were generally being used), 50% trash fish with little direct human consumption use, and the remaining 20% is trash (e.g. jellyfish, starfish and empty shells) which are dumped directly into the sea. (F Teutscher - Pers comm.)
Assuming that technical measures for bycatch reduction in shrimp trawling are never going to be perfect and the production of shrimp will continue to be a lucrative business and earner of foreign exchange there will always be quantities of fish which are presently discarded which could be used for inclusion in the human food cycle. Past experience has shown that although technically it is possible to produce human food stuffs from the mixture of small fish, that make up the bycatch, in most situations the economic and financial incentives and marketing opportunities for such products precludes their wide-scale adoption. The identification of the species involved and the likely quantities of particular species as well as the exchange of information and experiences between different regions would assist in the development of more complete discard utilisation and direct the research and development activities required.
As the pressure on traditional fish stocks has increased and the demand for fish products has continued to grow the resultant shortage seems to have had a positive impact on the amount of fish from the incidental catch which is used. This has been a natural progression and seems to be most successful where fishery products made from the bycatch can be assimilated into existing processing and marketing systems.