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International Journal of Aquaculture, 2013, Vol.3, No.8, 35
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37
35
Research Report Open Access
A Snapshot of the Fish Fauna in Lake Sebakwe, Zimbabwe: A First Record
Beaven Utete , Taurai Bere , Christabel Sithabile Tsotsonga
Chinhoyi University of Technology, Department of Wildlife and Safari Management, P Bag 7724, off Chirundu Road, Chinhoyi, Zimbabwe
Corresponding author email: Beaven Utete:
;
Authors
International Journal of Aquaculture, 2013, Vol.3, No.8 doi: 10.5376/ija.2013.03.0008
Received: 26 Mar., 2013
Accepted: 7 Apr., 2013
Published: 24 Apr., 2013
Copyright © 2013
Beaven. This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Beaven, 2013, A Snapshot of the Fish Fauna in Lake Sebakwe, Zimbabwe: A First Record, International Journal of Aquaculture, Vol.3, No.8 35-37 (doi:
10.5376/
ija.2013. 03.0008)
Abstract
This research is a snapshot survey of the fish species fauna in a tropical lake, Lake Sebakwe, in Zimbabwe. This is the
first record of the fish species present in the lake which was built to provide irrigation water and for recreational purposes.
Continuous intensive gill and seine fishing was done over five days in the lake and 8 fish species were collected. The exotic Northern
largemouth bass (
Micropterus salmoides
Lacepede, 1802) dominates the system. It appears the fish we sampled favour clear still
waters which can act as a pointer to the water quality of the lake.
Keywords
Fish fauna; White waters; Potamodromous; Lake Sebakwe
Introduction
Lake Sebakwe was originally completed in 1957 on
the Sebakwe River, but it was raised by 7 m between
1982
and 1986. The dam was built as a buttress
section, with downstream face slabbed over the
spillway zone. It has a mean height of 47 m, a
maximum water depth of 40.2 m and an area of 2 320 Ha
and a maximum volume of 105 000 m
3
.
It was mainly
built for supplying water to the downstream city of
Kwekwe and irrigating surrounding commercial farms.
The lake has a huge potential for fisheries, but a few
subsistence small scale fisheries exist. There have
been no studies on the fish community assemblages
of the Lake. Hence this brief snapshot survey of the fish
species resident in the lake. We sampled continuously
in the lake for four days using a combination of gill
and seine nets. Gillnets of both cotton and monofilament
were set up overnight. At each site nylon survey nets
(10
metres with a mesh size 1.5 inches, 2 inches, 2.5 inches,
3
inches, 3.5 inches, 4 inches, 4.5 inches, 5 inches,
5.5
inches and 6 inches) were set. Gillnets were set at
a distance of 30 metres apart to cover as much of the
lake as possible (King, 1995). Gillnets were also
described as the most effective in still water by
Bell-Cross and Minshull (1988).
Gill nets were set from 1 600 hrs–0600 hrs and
sampled fish were identified to species level according
to Skelton (2001), counted, measured to the nearest
millimeter and weighed to the nearest gram. The catch
per unit effort was standardized according to the
sampling method (numbers per net day for gill nets).
Fish data that is species present, their abundance and
sex were collected for each net and the total figures
for each sampling station collected.
A total of 8 species belonging to 6 families were
recorded in Lake Chivero for the sampling period. The
families were: Cichlidae;
Tilapia rendalii
(
Boulenger, 1896),
Serranochromisrobustus
:
Cyprinidae;
Labeo cylindricus
(
Peters 1868): Clariidae;
Clarias gariepinus
(
Burchell, 1822):
Momyridae;
Mormyrus longirostris
(
Peters, 1852),
Marcusenius pongolensis
(
Fowler, 1934): Centrarchidae;
Micropterus salmoides
Lacepede, 1802: Alestiidae;
Brycinus imberi
(
Peters, 1852). One exotic species
was recorded in the lake (
Micropterus salmoides
),
one
introduced species was observed
(
S. robustus
).
The
most frequent species has been the
Micropterus
salmoides
accounting for 60% of the catch in the
period sampled (Table 1).
A snapshot collection of fish species in Lake Sebakwe
reveal a dominance of the exotic Northern large mouth
bass (
Micropterus salmoides
,
Lacepede, 1802). This
fish is a predator that feeds primarily on fish, although
some invertebrates are taken and shows ontogenetic
diet shift (Marshall, 2010). This fish thrives in waters
where there is an absence of more voracious predators.
This may be the case in this lake as we found no other
competing predators like the tigerfish (
Hydrocynus
