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The use of traps and the
need for conservation of Synodontis fisheries in Asa
Lake, Ilorin, Nigeria
P. A. Araoye
Department
of Biological Sciences, Benue State University, Makurdi,
Nigeria.
E-mail:
araoyepa@yahoo.com.
Accepted 6
April, 2009 |
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The basket conical traps are commonly used to catch
Synodontis species by the fishermen in Asa Lake, Ilorin,
Nigeria because these species are caught alive to attract
higher market values. Fleets of these traps randomly set at
the bottom shoreline by fishermen at three different
locations around the lake from the dam site to the river
source were examined for Synodontis catch in 12
months. The specimen of Synodontis schall and
Synodontis gambiensis were encountered with the latter
occurring in August to October corresponding only with the
flood season around the lake. S. schall occurred
throughout the seasons but more abundantly in the traps
during the dry season. All the specimens of Synodontis
caught were found alive with mean standard length ranging
from 7.8 to 16.75 cm for S. schall and 16.8 to 22.48
for S. gambiensis. Their corresponding weights ranges
are 12.50 to 77.45 g and 49.75 to 92.76, for S. schall
and S. gambiensis, respectively. Gravid specimens of
both species were caught between the months of June to
August in both the fixed and the lost traps. A total of 18
lost traps were recovered during the 12 months of research
particularly during the flood seasons. There were no lost
traps in November to March. The period of low catch (October
and November) also corresponded with the season when the
juveniles of S. schall became abundant in the lake.
The total fish catch in the wet and dry season was
significantly different (P<0.05) in both species. ‘Ghost
fishing’ a phenomenon that usually occurred when the set
traps were lost due to high floods around the lake and the
need for conservation of these valuable water resources are
discussed.
Key
words:
Traps, Synodontis, ghost fishing, conservation. |
