Drum traps selectivity and catch efficiency in Lagos Lagoon South – Western Nigeria

Abstract

The efficiency of the drum trap in Lagos lagoon was investigated bi–monthly during day and night between May and September 2017 to know the effectiveness of the traps. Fish species recorded in this study consisted of two hundred and twenty fishes belonging to three families. Fin (1) and shellfishes (2) caught in the study include Tilapia zilli, Callinectes amnicola and Macrobrachium vollenhoevenii. Length range of M. vollenhoevenii, C. amnicola and T. zillii were 3.0 – 5.3 cm, 2.8 – 10.1 cm and 10.3 – 13.2 cm respectively with the corresponding weight range of 0.5 – 3.0 g, 3.0 – 96.0 g and 21.0 – 37.0 g respectively. Drum trap was highly selective for M. vollenhoevenii, as it represented 79.1% of the entire catch. More catches were recorded in the nighttime (145) compared to the daytime (75). A major challenge to the drum trap operation is the weight of the trap, if not properly handled while retrieving, catches could make a small planked canoe to capsize. It is therefore advised that the technical know-how of the trap operation being important, be mastered to forestall negative eventuality. Drum trap is therefore concluded to be highly a selective fishing gear for M. vollenhoevenii in Lagos lagoon.