Utilization of Two Brackish Water Systems Near Cape Coast (Ghana) as Nurseries for Juvenile Marine Fishes
The results of a 6- month study of marine juvenile fish communities of two brackish water bodies (Kakum River Estuary and Benya Lagoon) in the Central Region of Ghana are presented. Fishes were sampled by using a 20 mm mesh cast-net from November 2016 to April 2017 over tidal and diel cycles. Twenty three marine fish species belonging to 15 families were from the Kakum River Estuary and Benya Lagoon which indicated low species richness compared to that reported in these same water bodies. Fishes of the family Mugilidae were dominant and the five species (Mugil bananensis, Mugil curema, Mugil cephalu, Liza falcipinnis, Liza dumerillii) sampled accounted for 54.63% of the fish from the estuary and 77.69% of the fish of the lagoon samples. The similarity indicators between the two communities (Index of similarity =0.89) during the study were similar and this reflected in the closeness of Shannon-Wiener index of diversity (H’) values of 2.05 for the estuary and 1.55 for the lagoon marine communities. The two water bodies showed diel variation in catch rate which were out of phase with each other. There were fluctuations over the diel cycle in the number of species entering the brackish waters, number of individuals and their biomass. These fluctuations did not correlate with variation in temperature but they appeared to be influenced by salinity of the estuary and the lagoon.
