EFFECTIVENESS OF LIGHT-EMITTING DIODES IN REDUCTION OF SEA TURTLE BYCATCH IN ARTISANAL BOTTOM-SET GILLNET FISHERY IN SELECTED SITES, NORTH-COAST KENYA

Abstract

The artisanal gillnet fishery is found in most of the world's oceans and is responsible for a high rate of sea turtle bycatch. Between December 2016 and December 2017, this study assessed the effectiveness of light-emitting diode (LED) lights in reducing sea turtle bycatch in bottom-set gillnet fishery at three fishing sites in north coast Kenya: Watamu, Ngomeni and Bwana Said. This study collected data through field experiments and 10 key informant interviews using semi-structured questionnaires. The data were analyzed using descriptive statistics in MS Excel and a t-test in the Statistical Package for Social Sciences (SPSS). During the investigation, ten boats each with a pair of control (non-LED) and illuminated (LED) gillnets were deployed, catching a total of 56 families representing 97 fish species. Both non-LED and LED gillnets had similar mean capture per unit effort (CPUE) of target species with common fish species such as whitespotted rabbitfish (Siganus sutor), mackerel tuna (Euthynnus affinis), and honeycomb stingray (Himantura uarnak). However, 56 sea turtles comprising 41 green, 9 hawksbills, 5 loggerheads, and 1 olive ridley were captured in control gillnets while 31 comprising 22 green turtles, 5 hawksbills, and 4 loggerheads were captured in illuminated gillnets representing an average by-catch of 8.7 turtles per boat during the study period. LED gillnets lowered the mean CPUE of sea turtles by 64.3% hence significantly reducing the sea turtle catch rate (p < 0.05). The green sea turtle ( Chelonia mydas), was the main species captured (n=63) compared to other species. Increased net handling times (n=5), high equipment expenses (n=3) and a lack of awareness among fishermen about the technology's efficiency n=1) were ranked as topmost among the challenges associated with this assessment. To implement this technique of extensively minimizing sea turtle bycatch, the study recommends stakeholder support and further testing of this bycatch reduction strategy in the gillnet fisheries in key areas of Kenya's