Requisite improvements to the estimation of seabird by-catch in pelagic longline fisheries: Improvements to the estimation of seabird by-catch

Commentary about the negative interactions with fisheries being the most pervasive of current threats to seabirds. It notes that the the first peer-reviewed paper on seabird by-catch by an Asian (Taiwanese) distant-water fleet operating in the high seas of the South Atlantic Ocean is forthcoming. It is noted that the reality is that by-catch observation focused only on 5% of overall effort is inadequate even for frequently-by-caught species, given the large spatial and seasonal heterogeneity in by-catch rates. In conclusion, the author notes that independent observer programmes for by-catch still need substantial expansion and improvement. Only then will they be sufficient for comprehensive by-catch assessments, and adequate monitoring of vessel compliance and the effectiveness of recommended by-catch mitigation at ocean basin scales.