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Abstract:
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The status of fisheries and seasonal variation in fish diversity in the Kodungallur-Azhikode Estuary (KAE) were investigated.
Total annual average fish production in the estuary declined significantly to 908.6 t with average yield of 5.4 kg ha-1 day-1,
when compared to earlier study; where 2747 t was reported. During the present study, 60 species of finfishes (belonging to
34 finfish families), 6 species of penaeid shrimps, 2 species of palaemonid prawns, 2 species of crabs (4 crustacean families),
6 species of bivalves and 2 species of edible oysters (3 molluscan families) were noticed. Finfishes were the major group that
contributed 69.62% of total fishery in the estuary and crustaceans (23.47%), bivalves (6.84%) and oysters (0.07%) also
formed good fishery. Many of the fish species in the estuary were observed as threatened (Horabagrus brachysoma, Channa
striatus, Channa marulius, Clarias batrachus, Heteropneustes fossilis and Wallago attu). The major fishing gears employed
in the estuary were gillnets, cast nets, stake nets, scoop nets, ring nets, traps and Chinese dip nets. Gillnets contributed 45%
of the total fish catch. Gillnets also showed highest catch per unit effort (CPUE) of 6.91 kg h -1 followed by cast nets
(1.85 kg h -1), Chinese dip nets (3.20 kg h -1), stake nets (3.05 kg h -1), ring nets (1.27 kg h -1), hooks and lines (1.35 kg h -1)
and scoop nets (0.92 kg h -1). The study implies that temporal changes in fish landing pattern of the KAE was mainly due to
environmental variability, habitat modification and fish migration; under the influence of south-west monsoon and
anthropogenic activities in the KAE. Results of the study suggest that spatio-temporal variations in the fish community
structure could be an indicator for anthropogenic stress and it should be considered for restoration programmes. |