Thinking Big - Taking a Large-scale Approach to Seabird Bycatch

Abstract

Seabird bycatch in industrial fisheries has been the focus of research and conservation concern since the late 980s (e.g. Weimerskirch & Jouventin 987, Bartle 99 , Brothers 99 ). Recent research has explored the impacts of seabird bycatch in longline (Tuck et al. 200 , Lewison & Crowder 2003) and in trawl fisheries (Weimerskirch et al. 2000, Sullivan & Reid 2003). Understanding the impact of fisheries bycatch on seabird species involves both quantifying the number of individuals affected (including lethal and sub-lethal effects) and determining the effect, if any, that bycatch could have at the population or community level. Fisheries bycatch is only one of several human-mediated disturbances that may threaten seabird populations. Introduced predators, toxin contamination, disease and other disturbances are also likely to impact negatively upon populations (Arcos et al. 2002, Finkelstein et al. 2003, Weimerskirch 2004). Ideally, the goal is to understand the relative effects of each of these putative threats on population growth. However, data limitations (quantity and quality), uncertainty with analytical methods and assumptions, and the difficulties associated with understanding dynamic, natural systems present formidable obstacles to quantifying the effects of fisheries bycatch and other disturbances. THINKING BIG—TAKING A LARGE-SCALE APPROACH TO SEABIRD BYCATCH