Paffen P., C. Lukwesa and L. Mwape, 1996, Frame survey results for the Zambian coast of lake Tanganyika, March 1995, and comparison with past surveys. FAO/FINNIDA Research for the Management of the Fisheries on Lake Tanganyika. GCP/RAF/271/FIN-TD/52 (En): 90 p.
ABSTRACT
In March 1995, 2 teams of 3 enumerators from the Department of Fisheries at Mpulungu, Ministry of Agriculture, Food and Fisheries, conducted a fishing village Frame Survey (FS) at the Zambian coast of Lake Tanganyika with help of LTR. The results were compared with past data.
In 1995 the Zambian fleet consisted of 1,677 vessels, 250 of which were broken or damaged and out of use. Active vessels included fishing boats (54%), lamp carriers (32%), auxiliary boats (4%) and transport vessels (4%). Fishing boats comprised wooden, planked canoes (82%), metal canoes (5%), dugout canoes (3%), catamarans (2%), fiber-glass canoes (2%) and industrial units (1%). The number of landing sites (107) and vessels have been almost equally distributed among the five areas into which the Zambian coast was divided for the purpose of statistical surveys by the Department of Fisheries in 1964. Most fishing was on the south and east coasts which had the highest number of landing sites per km (0.7 and 1.0) and vessels per landing site (19 and 18), particularly in and near Mpulungu. Area V (10 km), at the border with Zaire, was not monitored but had some landing sites.
The number of traditional and artisanal vessels doubled in 30 years, from 755 in 1964 to 1,560 in 1995 while the number of dugout canoes remained similar. This is thought to be due to the introduction of large, artisanal gears in the 1960s-70s, which could not be operated with dugout canoes. In 1995 the traditional fishery employed 731 hand lines, 24 long lines and 2,950 gill nets. Gill net numbers have increased from 2,088 in 1970. In 1995 the artisanal gear used comprised 154 kapenta (night) beach seines, 30 traditional (day) beach seines, 27 lift nets and 16 chiromila seines. The largest increase was in the use of kapenta beach seines (from 23 in 1970) to make up 68% of the total artisanal gear. The number of liftnets increased in the 1990s, from 3 in 1990 to 27 in 1995.
Gill netting appears to have been the only traditional fishing method that has withstood the introduction of the artisanal fishing methods in the 1960-70s and remains popular. The use of long lines declined drastically after the 1960s. Lusenga nets were not used after the 1980s. This fishery was most popular in the early 1960s and used nets constructed entirely from mosquito nets (stretched mesh size < 2 mm). It was replaced during the 1970s and 1980s by the artisanal light, kapenta seine fishery which operates nets without a codend and a stretched mesh size of 6 mm. Thus the use of small meshes continued to characterize the local fisheries with the difference that kapenta seines were operated closer to shore and were larger than lusenga nets. As a result, the main species targeted may have shifted from both clupeids to juvenile Limnothrissa miodon.
Past catch data does not distinguish between traditional and artisanal fishing. The combined landings increased from 1,000-5,000 MT/year in the 1950s to 8,000-10,000 MT/yr in the early 1990s. Records for the industrial fishery started in 1962. In 1995, the industrial fishing fleet comprised 7% of the total fleet. The number of industrial units in Mpulungu increased from 1 in 1983 to 22 in 1995. The number of similar units based in Nsumbu (area IV) declined from 4 in 1983 to 1-2 in 1990. The CPUE of industrial units in Mpulungu decreased from 3,536 kg/trip in 1963 to 880 kg/trip in 1994. The contribution of the industrial catch to the total catch was approximately 19%/yr up to 1971 increasing to 36% during 1989-1992. After 1992 it decreased from 4,000-7,000 MT/year to less than 4,000 MT/yr. This suggests that the industrial fishing effort reached a maximum in the late 1980s and early 1990s and that the pelagic stocks targeted have been overfished.
The following recommendations are made:
(1) To increase the total production, the artisanal kapenta seines should be modified to allow juvenile L. miodon to escape or should be forbidden. Effective adaptations would be the use of meshes > 8 mm and the construction of a codend.
(2) The use of artisanal lift nets and chiromila seines should be encouraged as they are generally less destructive for the sustainable exploitation of clupeids than kapenta seines.
(3) To assure continuous high yields for the industrial fishery, it is advisable to reduce the number of industrial units to 16, the number employed in the late 1980s.
(4) DOF/Chilanga should publish past, statistical data from CAS, SFS and FS on Lake Tanganyika including collection methods and fishing effort. These data should be made available at DOF/Mpulungu.
(5) Detailed reports which include suitable measures of fishing effort, like those which have been collected during SFS since 1992, should be provided annually by DOF/Mpulungu. The type of fishing vessels employed (dugout canoe, canoe, catamaran) and the number of fishing nights per type of gear should be recorded.
(6) In order to ensure a consistent methodology, statistical surveys on Lake Tanganyika should be carried out by DOF/Mpulungu rather than a team of enumerators from Chilanga.
(7) An adequate budget is required for DOF/Mpulungu to perform seasonal CAS and SFS surveys or (bi)annual FS surveys if the SFS are not conducted properly.
