Trends in the abundance of marine fishes

Abstract

The Convention on Biological Diversity (CBD) established a target in 2002 to reduce the rate of biodiversity loss by 2010. Using a newly constructed global database for 207 populations (108 species), we examine whether the 2010 target has been met for marine fishes, while accounting for population biomass relative to maximum sustainable yield, BMSY. Although rate of decline has eased for 59% of populations declining before 1992 (a pattern consistent with a literal interpretation of the target), the percentage of populations below BMSY has remained unchanged and the rate of decline has increased among several top predators, many of which are below 0.5BMSY. Combining population trends, a global multispecies index indicates that marine fishes declined 38% between 1970 and 2007. The index has been below BMSY since the mid-1980s and stable since the early 1990s. With the exception of High Seas pelagic fishes and demersal species in the Northeast Pacific and Australia – New Zealand, the multispecies indices are currently below BMSY in many regions. We conclude that the 2010 CBD target represents a weak standard for recovering marine fish biodiversity and that meaningful progress will require population-specific recovery targets and associated time lines for achieving those targets.