Current and recent studies demonstrate the need for a more precautionary approach to fisheries management, in which fishing is restricted to those places and amounts where it can be conducted safely and with minimal risk of jeopardizing the integrity of marine ecosystems. Of even greater concern, most species are on a continuing trajectory of decline." Costello et al. found that fisheries that represent 80 percent of the world's catch are in worse shape than those than those on which global status reviews have been conducted. Traditional fisheries management focuses on obtaining maximum sustainable yield (MSY), which is a single-species approach that does not take into consideration the effects of the fishing on the entire ecosystem, including declines of other fish and marine animal species.