Effectiveness of Crab and Lobster Traps

Abstract

Traps are a versatile and powerful fishing gear. Desired species and sizes can be targeted through trap design and the choice of bait. Size of the catch is affected by trap size, bait quantity and quality, time between setting and hauling, and preventing escape through the entrance. But the largest potential for increasing trap catches is by increasing ease of entry and reducing the effect of gear saturation (animals inside traps preventing those outside from entering). Using catch per trap as an index of abundance is attractive for both fisheries management and ecological studies. However, correlations between catch and abundance have not been well established, probably because of the many factors affecting catchability (e.g. stage of the molt and reproductive cycles, sex, animal size, lunar and diurnal cycles, temperature, and water motion). Methods for conducting trapping surveys, measuring catchability, and comparing fishing strategies are critically reviewed.