Understanding how threatened species are distributed in space and time can have direct applications to conservation planning. However, implementing standardized methods to monitor populations of wide-ranging species is often expensive and challenging. In this study, we used baited remote underwater video stations (BRUVS) to quantify elasmobranch abundance and distribution patterns across a gradient of protection in the Pacific waters of Costa Rica. Our BRUVS survey detected 29 species, which represents 54% of the entire elasmobranch diversity reported to date in shallow waters (< 60 m) of the Pacific of Costa Rica. Our data demonstrated that elasmobranchs benefit from no-take MPAs, yet large predators are relatively uncommon or absent from open-fishing sites. We showed that BRUVS are capable of providing fast and reliable estimates of the distribution and abundance of data-poor elasmobranch species over large spatial and temporal scales, and in doing so, they can provide critical information for detecting population-level changes in response to multiple threats such as overfishing, habitat degradation and climate change. Moreover, given that 66% of the species detected are threatened, a well-designed BRUVS survey may provide crucial population data for assessing the conservation status of elasmobranchs. These efforts led to the establishment of a national monitoring program focused on elasmobranchs and key marine megafauna that could guide monitoring efforts at a regional scale.

Introducción: El Pacífico Norte de Costa Rica es una región diversa y productiva; sin embargo, tenemos un escaso conocimiento sobre el estado de los recursos marinos y la dinámica pesquera, particularmente de la pesca artesanal en el Golfo de Santa Elena, uno de los principales caladeros de la zona. Objetivo: Caracterizar la dinámica de esta pesquería. Métodos: Se analizaron los datos recopilados por el Instituto Costarricense de Pesca y Acuicultura y las facturas pesqueras de los sitios de desembarque para el período 2010-2019. Resultados: Hubo una alta variación en la biomasa desembarcada, sin embargo, la captura total por unidad de esfuerzo (CPUE; kg/día) y de las principales especies objetivo no disminuyó significativamente. En general, hubo una CPUE más baja en los meses de surgencia (diciembre-abril). De las 42 especies comerciales reportadas, la mayor biomasa provino del pargo mancha (Lutjanus guttatus; 22 % de la biomasa), el pargo seda (L. peru; 18 %), las cabrillas (Epinephelus spp.; 15 %) y el pulpo (Octopus spp., 13 %). Conclusiones: La CPUE en Santa Elena no ha disminuido significativamente de 2010 a 2019, pero disminuye en la época de surgencia.

Introduction: Tropical nature is experiencing an unprecedented threat that includes coastal fish communities that requires a close monitoring of species presence. The simultaneous use of several monitoring methods should reduce the bias caused by the selectivity of each method. Objective: This study used four different sampling methods over two years to assess and compare fish assemblages in the Santa Elena Bay Marine Management Area (AMM-BSE), North Pacific of Costa Rica. Methods: We examined changes in species richness and composition between upwelling and non-upwelling seasons from July 2019 and February 2020. We applied visual censuses, underwater remote cameras; bottom lines; and sport fishing. Results: We identified 140 species of fish (54 families); remote underwater cameras detected 83 %, followed by underwater visual censuses (65 %), sport-fishing (16 %) and bottom lines (14 %). Only the sport-fishing method detected differences in species richness and composition between seasons. Conclusion: Remote cameras appear to be the best method for species counts, and sport-fishing to detect seasonal differences in tropical coasts similar to the one studied here.