Center for Biological Diversity

For Immediate Release, May 16, 2016

Contact: Abel Valdivia, (510) 844-7103,

Study: Biodiversity Essential to Protect Ocean Fishes From Climate Change

WASHINGTON— Biodiversity is essential to maintaining the health of our oceans in the face of climate change and ensuring an adequate supply of the fish that billions of people around the world rely on for protein, particularly in developing countries. That’s the conclusion of important new research published today in the Proceedings of the National Academy of Sciences. The study suggests that maintaining biodiversity by reducing overfishing in reef ecosystems is crucial not only to promote food supply, but also to resist the impacts of rising temperatures caused by the rampant burning of fossil fuels.

“Biodiversity can buffer ocean fish populations against climate change. Protecting marine biodiversity by reducing overfishing can boost global fish production and improve ocean health in an era when human population is increasing and our oceans are rapidly changing,” said Abel Valdivia, an ocean scientist with the Center for Biological Diversity, which was not involved with the study. “This study really shows why biodiversity in our oceans is so important.”

The study analyzed the “Reef Life Survey” — a global database of more than 4,500 standardized fish surveys and more than 3,000 fish species from coral and rocky reefs around the world — and looked at 25 environmental drivers, finding that biodiversity, temperature and human influence together accounted for almost half of the differences in reef fish biomass. The study showed that reef ecosystems throughout the world with more fish species are generally more productive and can better cope with the continuing rising of water temperatures and extreme temperature fluctuations that are associated with climate change.

“People worldwide depend on fish on a daily basis, a lifeline that's threatened by climate change and overfishing,” said first author Emmet Duffy, director of the Tennenbaum Marine Observatories Network and senior scientist at the Smithsonian Environmental Research Center. “The study provides the most convincing evidence yet that biodiversity, the variety of species present, is not just an aesthetic issue but provides strong and tangible benefits to people by boosting fish production and resilience in a changing climate.” 

Biodiversity and temperature had strong influence in fish production. Warmer ocean temperatures increase fish biomass, probably through metabolism and by increasing diversity. But extreme temperature variability, a direct result of climate change, tends to substantially reduce fish biomass. In contrast, biodiversity — which includes the number of species in an ecosystem and the different ways these species use their environment — boosted fish biomass, particularly for large predatory fish that are highly targeted by fishers.

“Fishes have been extraordinarily depleted on most the world’s reefs. This new study suggests that reversing this trend through innovative management approaches to restore fish populations could benefit people and help reef ecosystems cope with other impacts,” said John Bruno, a marine ecologist and professor at the University of North Carolina at Chapel Hill, who was not involved in the study. “Although I’m very concerned about ocean warming, there is no doubt in my mind the primary impact to reef ecosystems is extreme overfishing.”

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1 million members and online activists dedicated to the protection of endangered species and wild places.

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