Short-term Estimate of Finfish Bycatch Discards in the Inshore Artisanal Shrimp Fishery of Guyana

The artisanal shrimp fishery in Guyana is important for livelihood and food security, involving around 300 vessels owned and crewed exclusively by Guyanese nationals. This fishery uses Chinese seines and operates in major river estuaries. It targets penaeid shrimp, but also retains some finfish and is known to discard a significant but undocumented quantity of smaller finfish bycatch. The lack of knowledge regarding the bycatch is a concern for fishery management and biodiversity conservation. In this study, we quantify for the first time the finfish bycatch discards through onboard observations (July-August 2016) of a single typical vessel operating in the Demerara estuary. Wet weights of the total catch, retained catch, and finfish discards were recorded separately for each of 76 seine hauls, and subsequently presented as catch rates per trip, catch rates per seine haul (kg/haul), and catch rates standardized per hour of seine net soak-time (kg/hr). A sub-sample of finfish discards was taken from every haul to determine taxonomic composition and species-specific length frequencies. Examination of 2,012 discarded finfish distributed among 32 species revealed high taxonomic diversity, none of which were considered vulnerable by the IUCN Red List. Most finfish discards were small (modal size class 5-7 cm fork length) and included juveniles of 15 species of importance to other fisheries in Guyana. On average, a standardized total catch rate of 14.8 kg was taken per hour of seine net soak-time, yielding 3.9 kg retained catch (shrimp and a few selected finfish), 10.3 kg of finfish bycatch discards, and 0.6 kg of miscellaneous invertebrate discards. This demonstrates significant wastage (finfish discards represent about 69% of the total catch weight) and potential for negative impact on biodiversity and other commercial fisheries. The information provided here addresses an important knowledge gap in the artisanal fisheries of Guyana.