Abstract:

Catch effort data on which fisheries management regulations are sometimes based are not available for most lakes in
Uganda. However, failure to regulate fishing gears and methods has been a major cause of collapse of fisheries in the
country. Fisheries have been damaged by destructive and non-selective fishing gears and methods such as trawling and
beach seining, by use of gill nets of mesh size which crop immature fish and by introduction of mechanised fishing. Selectivity
of gears used to crop Lates niloticus L(Nile perch), Oreochrornis niloticus L. (Nile tilapia) and Rastrineobola argentea Pellegrin
(Mukene) which arc currently the most important commercial species in Uganda were examined in order to recommend the
most suitable types, sizes and methods that should be used in exploiting these fisheries. Gili nets of less than 127 mm mainly
cropped immature Nile tilapia and Nile perch. To protect these fisheries, the minimum mesh size of gill nets sliould be set at
127 mni. Seine nets of 5 nun caught high proportions in immature Mukene while those of 10 mm caught mainly mature
Mukene. When operated inshore, both sizes caught immature Nile perch and Nile tilapia as by-catch. To protect the
Mukene fishery and avoid catching immature bye-catch, a minimum mesh size of the Mukene net should be 10 mm operated
as Lam para type net offshore, but since most fishermen have been using 5 mm seine nets for over five years the minimum
size should not be allowed to drop below 5 mm pending further thorough investigations. Beach seining and trawling are
destructive to fisheries and should be prohibited until data that may justify their use is available.