Intrinsic vulnerability in the global fish catch

Abstract

We have identified the marine fish taxa that are most vulnerable to exploitation, by compiling an index of intrinsic vulnerability based on life history traits. Since 1950, the global fish catch has been increasingly dominated by species with low intrinsic vulnerability, indicated by a decline in mean vulnerability of the taxa in the catches. This decline is strongest in catches of coral reef fishes, probably as a result of overexploitation of the more vulnerable species. The change is less apparent in estuaries, where fish communities are more transient. The opposite is observed at seamounts, where more vulnerable species have become exploited and serially depleted in recent years. Rates of change in the mean vulnerability index in the catches from different areas are negatively correlated with the number of threatened fishes on the IUCN Red List. Particularly, catches from the Indo-Pacific and Caribbean regions are characterized by a high abundance of threatened fishes and by strong declines in the mean vulnerability index. Our findings suggest that fishing largely alters the community structure of coral reef fishes, which may detrimentally affect the ecosystem. Attention should also be given to deep water demersal and benthopelagic fish assemblages, especially those around seamounts, which are intrinsically vulnerable to fishing. The index of intrinsic vulnerability thus provides a novel tool for fisheries management and conservation. © Inter-Research 2007.