Abstract:

This study was undertaken in Napoleon gulf, Lake Victoria Uganda from July -
December 2009. It was conducted in four landing sites; Bukaya (0.41103N, 33.19133E),
Bugungu (0.40216N, 33.2028E), Busana (0.39062N, 33.25228E) and Kikondo (0.3995N,
33.2I848E) all from Buikwe district (Formerly part of Mukono district). The main aim
was to determine the effect of both hook size and bait type on the catch rate (mean
weight) and size composition of Nile perch (Lates niloticus) (LINNE) fishery in the
Napoleon Gulf, Lake Victoria.. The main hook sizes investigated during the experiment
were 7, 8, 9, 10, 11 and 12 that were dominantly used in harvesting Nile perch in
Napoleon Gulf, Lake Victoria. In this study length, weight and bait type data were
collected on site from each boat at that particular fishing spot; since most fishermen in
the Napoleon Gulf could sell their fish immediately the catch is caught there and then.
The results indicated a total of 873 Nile perch fish samples collected during the study.
Statistical tests, descriptive statistics, regression and correlation were all carried out using
the Statistical Package for the Social Sciences (SPSS) in addition to Microsoft excel. The
bait types in the Gulf ranged from 5-10 cm Total length (TL) haplochromine, 24.5-27 cm
TL Mormyrus kannume and 9-24 cm TL Clarias species. The bait types had a significant
effect on the catch rate and also on the size composition the fish harvested measured as
Total length (ANCOVA F=8.231; P<0.05) despite the fact that bait type had no influence
on mean weight of fish captured (ANCOVA F=2.898; P>0.05). Hook sizes used by the
fishers had a significant effect on the both the size (TL) composition (ANCOVA
F=3.847; P<0.05) and the mean weight (ANCOVA F=4.599; P<0.005) of the Nile perch
captured. Investigations indicated hook sizes seven (7) and eight (8) were the ones that
harvested the Nile perch above the slot size of 50 cm total length. In general hook sizes
indicated to be the main drive in the harvesting of the Nile perch though bait type also
contributed toward that. Generally there is need for management to put a law in place on
the minimum hook size to be used on the harvesting of the Nile perch and also monitored
by the Fisheries Management as a regulatory measure. In addition to that aquaculture
should be encouraged to farm the fish for bait at a higher scale in the region in order to
avoid depleting the wild stocks already in danger of extinction. Through this kind of
venture, both biodiversity conservation and environmental sustainability will be observed
in the Lake Victoria basin.