A trap with light-emitting diode (LED) lights: Evaluating the effect of location and orientation of lights on the catch rate of snow crab (Chionoecetes opilio)

Abstract

This study investigated the effect of installing underwater light-emitting diode (LED) lights in different locations (close and distant to the trap entrance) and orientations (normal and upside down direction) inside baited traps targeting snow crab (Chionoecetes opilio) off the coast of Newfoundland and Labrador, Canada. Four experimental treatments were evaluated in comparison with traditional baited traps (control). Our results showed each of the experimental treatments produced significantly higher (39%–57%; 48% on average) catch per unit effort (CPUE) compared to the control traps, with no significant differences for both legal and sublegal-sized crab among the different experimental treatments. Longer soak times significantly increased the CPUE of the illuminated traps, but did not affect the catch rate of the control traps. Our results also indicated crab size frequency distributions were independent of experiment treatments. Our results suggest that fishing enterprises could improve their catching performance by adding LED lights to their traps, but the location and orientation of the lights appears unimportant. Keywords: LED, Crab trap, CPUE, Inshore fishery, Catchability