SOME CONSIDERATIONS FOR THE
MANAGEMENT OF COASTAL LAGOON AND ESTUARINE FISHERIES
Relative to marine and inland waters, the fisheries of coastal lagoons and estuaries in developing countries have received little attention up to the present. A number of factors have contributed to this situation. One is that coastal lagoons and estuaries do not easily fit into the usual “Marine” and “Inland” categories under which most national fishery departments are presently organized. Secondly, the fisheries of coastal lagoons and estuaries are often based on multi-species resources which vary widely in availability in time and space -- marine “visitors”, euryhaline “permanent residents”, freshwater “visitors”, and migratory catadromous and anadromous “transients”. This stock complexity contributes to the difficulty of resource evaluation, and hence to the formulation of management programmes. An additional reason for the relative neglect of lagoon and estuarine fisheries in developing countries is that they are in the main small-scale and of an artisanal or subsistence character. The fisheries are usually operated by individuals or family groups using traditional labour-intensive fishing methods from small craft. Fishermen and fishing communities may be widely dispersed, and much of the catch may be sold informally through local channels with only the most valuable fishery products entering national statistical tables, and then usually without mention of the lagoon or estuarine origin of the product.
Some of the same characteristics which make coastal lagoon and estuarine fisheries difficult to manage also make them relatively valuable in their own right, or important for their potential or actual effect on other fisheries. Among these are that some of the same stocks which are fished at varying levels of intensity in lagoons and estuaries also support offshore marine industrial fisheries or nearshore coastal artisanal fisheries, for example, for shrimp. Biologically, estuaries and lagoons provide nursery areas for fishes and crustaceans which spend the remainder of their life cycles at sea, or in fresh waters. Further, lagoons and estuaries provide avenues of entry and exit for migration of anadromous and catadromous fishes. From the socio-economic viewpoint the small-scale, labour -intensive character of the fisheries provides income, employment, and protein self-sufficiency for coastal fishing peoples while the surplus catch contributes to the food supply at nearby urban centres. In some situations where high-value resources are exploited for export, such as shrimps, crabs, and oysters, the lagoon and estuarine fisheries also contribute to the national economy by providing a source of foreign exchange. Finally, estuaries and lagoons of developing countries increasingly provide opportunities for a rapidly developing aquaculture industry and for recreational fisheries. Clearly, the importance and complexity of coastal lagoon and estuarine fisheries demand that they should be well-managed if their fishery resources are to be exploited in an optimum manner and if the maximum of social and economic benefits are to be realized from their resources.
In this context, this report is aimed at filling a need for information on the management of coastal lagoon and estuarine capture fisheries in developing countries. In part, the report serves to indicate the status of fishery management activities in coastal lagoons and estuaries. At the same time, using examples drawn from a number of fisheries in differing technological, economic and social situations, it provides an overview of the scope of management activities available. An additional feature is that an attempt has been made to anticipate fishery interactions and conflicts which may become important management considerations in the near future.
The present report confines itself rather rigidly to the management of fisheries per se; however, a subsequent report is planned which will deal with the broader aspects of fishery management in coastal lagoons and estuaries -- management of fisheries in relation to environmental alterations and pertubations, and fisheries within the multiple-use context of lagoons and estuaries. Likewise, another report now in preparation, will be a compilation of information on fishery yields and yield prediction in coastal lagoon and estuaries.
The general approach used in this report is to illustrate management problems, and to examine management solutions which have been applied or proposed by using examples taken from a number of lagoon and estuarine fisheries. In this manner considered first are the classical approaches to the management of lagoon and estuarine fisheries -- regulation of entry, restrictions on fishing gears, on locations, and on fishing seasons. Also included is the possibility of revitalizing traditional fishery management methods. Then, the focus turns to various possibilities for the management of lagoon and estuarine fisheries through non-regulatory methods, those which increase fishery productivity -- hydraulic engineering, predator control, stocking, and brush-park fisheries. Finally, from a different perspective, management of lagoon and estuarine fisheries is considered from the viewpoint of actual or potential interactions, competition or conflicts, with other kinds of fisheries -- ethnic and socioeconomic interactions, potential conflicts with aquaculture, and interactions with marine nearshore and offshore fisheries.
