30. The Secretariat introduced document CIFA/83/Inf.5. Reservoir fisheries in Africa are important by virtue of the area they occupy, some 30 000 km2 for reservoirs exceeding 10 km2, and for their contribution to overall inland fishery yield in Africa, which amounts to about 10 percent or 150 000 t.
31. Despite their present importance (and future potential as more reservoirs come into being) the full biological and economic potentials of reservoir fisheries have rarely been realized. There are a number of reasons for this. Firstly, reservoirs have been established for purposes other than for fisheries. Secondly, even when substantial fishery benefits were expected from reservoir projects, the participation of fishery experts came much too late in the planning process. Thus, fisheries problems were not considered in the engineering design, nor provided for in basin development plans. On the other side, fisheries specialists have not always been able to provide appropriate or timely advice.
32. However, much experience has been accumulated in Africa which is relevant to the above needs. Further, there are now many workers who have gained experience in the half dozen large man-made lakes in Africa as well as a number of smaller ones. Many specialized papers and reports have been published. Yet little has been done to synthesize this experience and to make it more readily available for the fishery workers and planners of Africa. Although this need has been recognized for quite a number of years, the first concrete steps towards producing such a synthesis have only recently been taken.
33. During its fourth session in 1980, the Committee recommended to the Secretariat that an activity should be undertaken to increase benefits from African reservoir fisheries. The following paragraphs report progress on this activity.
34. Action by CIFA on the execution of this activity during the last intersessional period - In 1981, as the first step of this activity, FAO obtained the services of Mr E.O. Ita, of the Kainji Lake Fisheries Research Institute, Nigeria, to frame the “synthesis”. His work included the assembly of a working bibliography on African reservoir fisheries, the preparation of a “model” national reservoir fishery synthesis based on experience at Kainji, and a common operational framework for the organization of national syntheses. With the output of Mr. Ita's work in hand, invitations to prepare national reservoir fishery syntheses were sent to prospective authors in a number of CIFA countries. Contributors of national syntheses were invited to participate in a 3-day Roundtable discussion to be held under the auspices of the CIFA Working Party on Stock Assessment. The Roundtable met in Cairo, Egypt, on 11, 12 and 13 January 1983. Syntheses of information were presented on reservoirs in Egypt, Ghana, Madagascar, Mozambique, Sudan and Zimbabwe.
35. The Roundtable emphasized planning at the early pre-impoundment stages of reservoir development as one of the means for increasing benefits from African reservoir fisheries. Discussions focused on improving capabilities for fishery yield prediction in reservoirs as a planning tool fundamental to estimating the kinds and magnitudes of fishery management and development inputs which would be required in the future reservoir. The summary of the Roundtable discussion on increasing benefits from African reservoir fisheries is given in Appendix D.
36. Planned CIFA activities on African reservoirs during the coming intersessional period
Immediate (1983) activities are:
Compilation of national syntheses together with the report of the Roundtable as a CIFA Technical Paper;
Final compilation and publication of “A Bibliography on African Reservoir Fisheries” in the CIFA publication series.
37. The Roundtable recommended a number of high priority activities to be completed in the form of concise studies and reviews, each of which might require one to two man/months to complete. These are the following:
A review of small pelagic fishes in African natural lakes and reservoirs and critical evaluation of their present contribution to yield and potentials for exploitation;
Formulation of a reservoir-specific yield prediction relationship based on updated catch data and morpho-edaphic indices from African reservoirs, and a search for other non-MEI parameters which can be used to increase the accuracy of reservoir fishery yield prediction;
A review of pre-impoundment studies to determine the most essential kinds of information required to adequately predict ecological and other conditions important to the management and development of reservoir fisheries;
Study of the feasibility of the enhancement of reservoir fisheries through dam design and reservoir operation;
A review of the experience from flooding totally uncleared areas, partially cleared ones, or those without vegetation, and its implications for fisheries;
Aquatic macrophyte development implications for reservoir fisheries.
38. Comments by delegates and discussions which followed focused on the applicability of the MEI yield relationship to small reservoirs and to the early post-impoundment phase. It was noted that the proposed intersessional activity on yield prediction implicity considered these problems (Recommendation (ii), above). Also, there was some debate on the pros and cons of brush and tree clearing in savannah versus tropically forested reservoirs. This should be explicitly taken up in the review on the implications of the inundation of cleared and uncleared areas (Recommendation (v), above). The importance for fisheries of small versus large impoundments was brought to the floor. This subject was discused at the Roundtable which noted that the number and cumulative area of such impoundments were large and therefore the potential for fisheries correspondingly important. As an additional activity during the intersessional period the Secretariat will undertake to begin to compile physical, chemical, biological and fishery information on such impoundments, as outlined in CIFA/83/Inf.5 (Addendum) and page 4, paragraph C of Appendix D.
