It is rare for marine protected areas to be mentioned in the International Journal of Epidemiology, which covers issues affecting human health and illness. But an article in a recent issue of the journal examines the relationship between increasing human demand for fish and the declining health of our ocean ecosystems. The article suggests that recommendations from health advocates that people eat more fish are on a collision course with recommendations from biologists that we conserve fish stocks.

Article co-author Peter Jones, a marine biologist at University College London, says there will not be enough fish to meet demand unless more effective conservation measures are implemented. “The collision the paper refers to is based on continuation of the ‘business as usual’ scenario of very few no-take marine reserves as well as broader fisheries management measures that often lead to over-exploited stocks,” says Jones. “If 20-30% of our seas were designated as marine reserves – and if they delivered spillover/export benefits to wider fisheries that more than compensated for the loss of grounds (in terms of fish yield) – then we could have marine reserves and eat more fish.” He says this would particularly be the case if there were also continued improvements in broader fisheries management, beyond just reserves.

Jones says marine reserves have a direct impact on human health by delivering a range of ecosystem services, including improved ecosystem regulatory functions and resilience. These benefits are not included often enough in fisheries management decision-making, he says. “While fisheries management is becoming more ecosystem-oriented, the benefit assessments remain primarily focused on the costs/benefits of different management options in terms of the fish stocks themselves,” says Jones. “A key aspect of the collision-avoidance strategy discussed in the article will be to include wider ecosystem services when considering the costs and benefits of fisheries management options. Given the challenges of assessing the value of such services, we should just accept that they will be generated and designate marine reserves on a precautionary basis.” For a PDF copy of the article “Fish, human health and marine ecosystem health: policies in collision?”, e-mail Peter Jones at