Media Release Fisheries

Fish size study shows benefits of marine sanctuaries

July 28, 2021

The Australian Marine Conservation Society (AMCS) says a new study released today by researchers at the University of Western Australia (UWA), which shows that larger fishes can be found in Australia’s no-take marine sanctuaries, is more evidence of the benefits of highly protected areas for our oceans.

The study, published in Conservation Biology, used underwater video to take over 1 million fish measurements of 82 fish species across 10,000km of Australian coastline and found larger fishes to be more abundant further away from human activity, as well as in no-take marine sanctuaries.

The findings were consistent across a range of different habitats including tropical reefs and cool kelp forests.

Cat Dorey, AMCS Marine Parks Campaign Manager, said the research showed the importance of highly protected marine sanctuaries in our oceans that allow fish to breed and replenish, resulting in greater numbers of bigger fishes.

“This is science proving that the best way to ensure our marine ecosystems are resilient is to have highly protected, no-take sanctuaries within marine parks. A greater number of bigger fishes is good for fishers, tourists and the incredible ocean wildlife we are trying to protect for generations to come,” she said.

“No-take marine sanctuaries are powerhouses for the areas around them, because what grows within them flourishes and spills out into surrounding environments.”

More information about the research can be accessed here.

Notes to editors

Groups of fish species studied include:

Plectropomus – coral trouts or coral groupers, Notolabrus – wrasses, Nemadactylus – morwongs, Lutjanus – snappers, Lethrinus – emperors, Choerodon – genus of wrasses known as tuskfishes.

One specific species studied was Chrysophrys auratus – pink snapper.

Areas off the coasts of WA, SA, VIC, TAS and QLD were surveyed.

Important factors for increasing the likelihood of seeing big fish included distance from human activity, depth (around 30m was best) and more complex seabeds which likely provide better food and shelter to fishes.