Appropriate scales and data to manage seabird−fishery interactions: Comment on Torres et al. (2013)

CROXALL, J., SMALL, C., SULLIVAN, B., WANLESS, R., FRERE, E., LASCELLES, B., RAMIREZ, I., SATO, M. & YATES, O.

MARINE ECOLOGY PROGRESS SERIES

INTER-RESEARCH

Año: 2013 vol. 493 p. 297 - 300

0171-8630

Torres et al. (2013; Mar Ecol Prog Ser 473:275−289) use fine-scale data on trackedlocations of one species of albatross and fishing vessels to make a variety of assertions on interactionsbetween them, especially in relation to risk of bycatch. Some of these assertions are incorrect,and we seek to clarify the issues and perspectives involved. We argue that while a fine-scaleapproach can provide interesting insights into foraging behaviour, large-scale risk analysis isneeded because management measures (e.g. for bycatch mitigation) need to operate across allvessels in a fishery and across all seabird species at risk from the fishing operation. In addition, anestimate of 10% time spent in close proximity to vessels cannot be used to infer low bycatch riskalone: such an inference would need comparison to bycatch rate data. The analysis also does nottake into account a number of factors known to affect the nature and duration of the association ofalbatrosses with fishing vessels, which limits the conclusions that can be drawn. However, finescalestudies can provide important insight into factors affecting individual bycatch events, andstudies at fine and broad scales will be complementary.