Abstract:

In July 2005, Catch Assessment Surveys (CASs) were conducted at 54 pre-selected fish landing sites in the Ugandan part of Lake Victoria. These constituted 10% of all landing sites in the 11 districts sharing the Ugandan waters. Data recording was by enumerators who were selected from the fishing communities and trained centrally in CAS procedures following the approved CAS Standard Operating Procedures (SOPs). Immediate supervision of enumerators was by the sub-county and district Fisheries Officers also trained together with the enumerators. The Officers from the Fisheries Resources Research Institute (FIRRI) and the Department of Fisheries Resources (DFR) carried out the training, distributed funds and materials to the districts, and made targeted supervision checks of field data. Raw data sheets were returned to FIRRI, analysed and prepared and this report prepared.

The data were captured using regionally harmonised field sheets. These data included the details of fishing effort, i.e. vessel and gear characteristics and fish catches. The data were analysed using Microsoft Excel to estimate CAS-based indicators for different effort group. The CAS indicators were estimated by vessel-gear combinations which constituted effort groups. The vessels were categorised into four groups, (i) Parachute, (ii) Sesse Paddle, (iii) Sesse motorized/Sail, and (iv) Other crafts. The different combinations of gears with the four vessel types constituted the effort groups.

Among parachute boats, the mean Nile perch catch rates by effort group were highest (22.7kg boat-1 day) among boats using unclassified gears that included beach seines followed by long lining boats (21.9 kg boat-1day-1). The highest Tilapia catch rates of parachute boats were from boats using monofilaments gillnets (25.0kg boat-1 day-1). The paddled sesse boats using beach seines and long lines had similar Nlie perch catch rates (24.5kg boat-1 day-1) which were also the highest in this boat category. Paddle sesse boats using monofilament gillnets, landed 23.5kg boat-1day-1. Boats operating in the Mukene/dagaa fishery using small seines landed 205.3kg boat-1day-1. The highest catch rates among the boats using motor or sail were in the long line fishery where they landed 45.1 kg boat-1 day-1 of Nile perch compared with 25.6 kg boat-1 day-1 of Nile perch landed by those using multifilament gillnets.

The total catch in the Ugandan waters of Lake Victoria for the month of July 2005 was estimated at 15,047.5 t contributed by Nile perch (4,977.7 t); Tilapiines (2,555.8 t); Mukene/Dagaa (5,944.1 t); Haplochromines (1391.6 t) and other fish species (178.3 t). Overall, Mukene/Dagaa contributed 39.5% of the fish landed, followed by Nile perch (33.1%), Tilapiines 17.0% and Haplochromines 9.2%. All other fish species contributed 1.2% of the total fish catches.

The catch rates of illegal destructive fishing gears were much higher than those of the legal gears, a possible reason for their persistence in the fishery. The Nile perch catch rates of the long lines were relatively better than gillnets which shows that this is a viable option for development of the Nile perch fishery but requires addressing the issues of scarcity of bait and capture of juvenile fish. Specific efforts are need in the Ugandan part of the lake to promote the taping of wind power using sails to improve access of Nile perch fishing grounds and development of the Mukene/Dagaa fishery that is still limited to inshore waters.