A new study revealed that the marine reserve network on the Great Barrier Reef is not just a tool for conservation but measurably contributes to the sustainability of local fisheries.

The Great Barrier Reef’s network of marine reserves is designed to protect its biodiversity. These reserves protect critical habitats for many species, including coral trout (also called coral grouper), the reef’s most valuable commercially fished species.

The research team, led by the Queensland University of Technology with colleagues from James Cook University, the Australian Institute of Marine Science and the Reef Authority, connected reef fish monitoring and commercial fishery catch datasets with advanced statistical and oceanographic models to estimate coral trout reproductive output and fish larvae dispersal patterns.

The study’s findings show that marine reserves support twice the biomass (measured as density and size of coral trout) when compared to fished reefs. Coral trout are also larger in marine reserves, resulting in a higher reproductive output. Despite protecting only 30% of coral trout habitat, the fish in marine reserves contribute 55% of total reproductive output of the species in the Great Barrier Reef. This benefits coral trout populations on all connected reefs as well as supporting a more sustainable fishery.

The study clearly demonstrates how well-managed marine reserves not only contribute to the protection of biodiversity of a coral reef ecosystem but also benefit local communities and the economy.