9.1 Studies in lagoons and rivers
9.2 Studies at sea
9.3 Important remarks
These directly follow the priorities defined in terms of management. Studies have been undertaken in various laboratories since 1966. The most complete ones have been made in the Ivory Coast and their synthesis has been published recently (Garcia, 1977). The results obtained on the distribution, ecology, behaviour, reproduction and migration of larvae and juveniles, etc., can possibly be generalized, with few exceptions, to the major part of the Gulf of Guinea and more particularly from Sierra Leone to Cameroon. The minimum programme to be executed in order to manage and use the stocks properly includes studies in the lagoons and at sea.
- surveys and delimitation of nursery grounds;- collection of statistics from the artisanal fishery: catches and effort;
- systematic programme of measurement of shrimps caught, if possible by area of capture;
- assessment of the duration of the lagoon phase of shrimps and the annual cycle of recruitment.
- Accurate delimitation of fishing grounds;- collection of statistics of catch and effort, per month and per fishing grounds;
- routine measurements and determination of the population structure of catches per year and per month (growth, cohort analysis).
Scientific research on Penaeus duorarum stocks are very advanced in the Ivory Coast and the simulated reactions of the stocks to the combined exploitation of adults at sea and of juveniles in lagoons have very often been referred to in this report. We are however not sure about the direct application of the model used for the Ivorian situation to other stocks of the region. It is therefore highly desirable that similar research be undertaken in other countries to be able to confirm or dismiss the Ivorian results. These studies should be undertaken preferably in areas with high potential (Benin, Nigeria, Cameroon).
