Item Details

Title: Fishing gear selectivity of Lates niloticus L.(Nile perch), Oreochromis niloticus L. (Nile tilapia) and Rastrineobola argentea Pellegrin (Mukene) in lakes Victoria, Kyoga and I Nabugabo.

Date Published: 2000
Author/s: Ogutu-Ohwayo, R., S.B. Wandera and 1. R. Kamanyi
Data publication:
Funding Agency :
Copyright/patents/trade marks:
Journal Publisher:
Affiliation: National Agricultural Research Organisation,
Fisheries Research Institute,
P. O. Box 343, Jinja, Uganda


Catch effort data on which fisheries management regulations are sometimes based are not I 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 I seining, by use of gill nets of mesh size which crop immature fish and by introduction of
mechanised fishing. Selectivity of the gears used to crop Lates niloticus 1. (Nile perch),
Oreochromis niloticus 1. (Nile tilapia) and Rastrineobola argentea (Mukene) which are I 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 . Gill nets of less than 127 mm mainly cropped immature Nile ti1apia and Nile perch. I To protect these fisheries, the minimum mesh size of gill nets should be set at 127 mm.
Seine nets of 5 mm do catch high proportions of immature Mukene while those of 10 mm
catch mainly mature Mukene. When operated inshore, both sizes catch immature Nile perch
and Nile ti1apia as by-catch. To protect the Mukene fishery and avoid catching immature byecatch,
a minimum mesh size of the Mukene net should have been 10 mm operated as Lampara
type net offshore but since most fishennen have been using the 5 mm seine for over five years I
the minimum size should not be allowed to drop below 5 mm pending further thorough investigations.