Almost two thirds of all coral reefs worldwide are currently overfished. This is the result of a study in which the Bremen Leibniz Center for Tropical Marine Research (ZMT) participated. Led by Jessica Zamborain-Mason from Harvard University, the experts evaluated data on fish observations in more than 2,000 reefs worldwide, as the ZMT announced.

“At almost two thirds of the locations, more is being fished than the biomass stocks can produce – so they are being overfished,” says Sebastian Ferse from the ZMT, summarizing the results of the study, which was published in the journal “Nature Communications”. The fish stocks in almost every tenth fished reef have already collapsed. They had less than ten percent of the biomass that the reef would have if no fish were caught there.

No reliable data for a long time

According to the information, the study provides an insight into the global state of reef fishing worldwide. The catch in these areas is mostly traded informally or consumed personally, so reliable data has not yet been available. For the study, the researchers counted fish underwater along defined areas and identified the species. Local fishing data were reconstructed using national statistics.

It is estimated that around six million people worldwide are involved in reef fishing. The share of catch from reefs in total marine fisheries is large in many regions: in the Near and Middle East it is 43 percent and in the Caribbean 40 percent.

Heel advocated for better local fisheries management and reduced fishing to 80 percent of the maximum possible yield. This would lead to a significant relaxation in stocks. “It is not necessary to ban fishing from the reef to save the ecosystem,” he emphasized. The study also showed the importance of individual environmental factors: In locations with higher water temperatures and lower coral cover, the maximum sustainable fishing yield is significantly lower.