Climate change, overfishing, pollution, and other factors are threatening coral reefs all around the world. Researchers have published the first comprehensive worldwide assessment at what these consequences on coral reefs mean for ecosystem services, or the reef’s ability to give important benefits and services to humans, in the journal One Earth on September 17. Overall, the data suggest that a major reduction in coral reef coverage has resulted in a similar reduction in the reef’s ability to supply fundamental services, such as food and livelihoods.
“Coral reefs are known to be important habitats for biodiversity and are particularly vulnerable to climate change, as marine heat waves can cause bleaching events,” said Tyler Eddy (@tyzissou), a research scientist at Memorial University of Newfoundland’s Fisheries & Marine Institute who was a postdoctoral fellow at the University of British Columbia’s Institute for the Oceans & Fisheries when he was a postdoctoral fellow at the University of British Columbia’s Institute for the “Through fisheries, economic opportunities, and storm protection, coral reefs provide vital environmental services to humans.”
To investigate these various aspects of the reef ecosystem, they analyzed global and country-level trends in ecosystem services using data from coral reef surveys, estimated coral-reef-associated biodiversity, fishery catches and effort, fishery impacts on food web structure, and Indigenous consumption of coral-reef-associated fish.
When all of the data is combined, it shows that the global coverage of living corals has decreased by around half since the 1950s. Coral reefs’ ability to supply ecosystem services has also increased. They discovered that coral reef fish catches peaked about two decades ago and have been declining ever since, despite increased fishing effort. The catch per unit effort (CPUE), a commonly used indicator of biomass variations, is now 60% lower than it was in 1950.
“Our analysis shows that coral reefs’ ability to deliver ecosystem services has decreased by roughly half globally,” said William Cheung, a professor at the University of British Columbia’s Institute for Oceans and Fisheries and the study’s senior author. “The relevance of how we manage coral reefs not only at regional dimensions, but also on a global scale, and the livelihoods of communities that rely on them, is highlighted in this study.”
The researchers also discovered that the reef’s species diversity has decreased by more than 60%.