A cost effective light trap for sampling tropical fish and crustacean larvae

Abstract

A simple and relatively cheap locally-assembled light trap was used to sample pre-settlement fish larvae in the Malindi Marine Park, Kenya, for two years. The trap was assembled locally using a water dispenser bottle, plastic bottle necks, buckets, 12V rechargeable alkaline batteries and a diver’s dry box. The light unit consisted of a 12 V rechargeable alkaline Jacob’s battery that powered a 12 volt energy saving fluorescent bulb of 11Watts. The catch potential and composition of fish larvae sampled using the trap is presented. The technical and functional problems encountered during the construction and operation of the light traps are presented, and improvements suggested. We compare the performance, costs and efficiency of this trap with light-traps used elsewhere in the world. In addition to fish larvae, the traps have potential use in qualitative sampling of crustacean larvae and ornamental fishes for the aquarium trade.