Dynamic habitat models: Using telemetry data to project fisheries bycatch

Abstract

Fisheries by catch is a recognized threat to marine mega fauna. Addressing by catch of pelagic species however is challenging owing to the dynamic nature of marine environments and vagility of these organisms. In order to assess the potential for species to overlap with fisheries, we propose applying dynamic habitat models to determine relative probabilities of species occurrence for specific oceanographic conditions. We demonstrate this approach by modelling habitats for Laysan (Phoebastria immutabilis) and black-footed albatrosses (Phoebastria nigripes) using telemetry data and relating their occurrence probabilities to observations of Hawaii-based long line fisheries in 1997-2000. We found that modelled habitat preference probabilities of black-footed albatrosses were high within some areas of the fishing range of the Hawaiian fleet and such preferences were important in explaining by catch occurrence. Conversely, modelled habitats of Laysan albatrosses overlapped little with Hawaii-based long line fisheries and did little to explain the by catch of this species. Estimated patterns of albatross habitat overlap with the Hawaiian fleet corresponded to by catch observations: black-footed albatrosses were more frequently caught in this fishery despite being 10 times less abundant than Laysan albatrosses. This case study demonstrates that dynamic habitat models based on telemetry data may help to project interactions with pelagic animals relative to environmental features and that such an approach can serve as a tool to guide conservation and management decisions. © 2011 The Royal Society.