The Perils Faced By Large Reef Fish

The global decline of coral reefs and reef fish has been well documented. However, it’s important to note that the effects of overfishing and reef decline are not uniform and evidence points to the decline being worse for large species. How much of the decline of reef species is due to overfishing (i.e., human activity) and how much is due to other effects? The jury may still be out, but the signs point to human involvement being the main culprit.

According to the Coral Reef Ecosystem Division of the National Oceanic and Atmospheric Administration, there are “huge differences between unpopulated islands… and populated islands” when it comes to the decline of species around the U.S. pacific islands and reefs. The differences are largest for apex predators. Other studies by the same agencies have found similar patterns in the northwestern Pacific Ocean. In the Indian Ocean, areas without human activity for several decades have found “an average fish biomass that is orders of magnitude higher than anywhere else in the Indian Ocean,” even higher than in some protected marine areas.

Still, there are other differences between fished and remote reefs and it can be hard to parse exactly how much human influence plays a role. Some studies have resulted in data that cannot be explained by fishing alone. This review of the pressures faced by reef fish finds that tourism may be another source of pressure associated with these species. The findings are tentative, but they show a potential correlation between reef tourism – and the dollar value of reef tourism – and reef fish declines.

The authors note that tourism around the Great Barrier Reef is worth about $2 billion per year and contributes “far more income to Australia than the fisheries on that same reef.” Tuna fishing in the Pacific is worth about $1.6 billion per year, while reef tourism in the Caribbean alone is about $6 billion per year. Reef tourism is a much larger industry than reef fishing and larger than tuna fishing in general. There is an estimated “half a million divers” each year that find, photograph, and swim with sharks. While these divers contribute to local economies, their activities may have unintended consequences.

This study is not an indictment of reef tourism or ecotourism more broadly. However, it is food for thought for marine animal advocates who want to protect reef fish. It may be challenging to find ways to save reef fish without monetizing the experience, but that may be the direction in which ecotourism needs to move to achieve its goals.