Seaweed threatens coral reefs in the Pacific

28.06.2016 09:03
Kategorie: News

Researchers call for more protection of herbivorous fish

Coral reefs in the Pacific Ocean are coming under increasing threat of the proliferation of seaweed. Historically, seaweeds were less commonly found in the Pacific compared to the Caribbean; however, corals have been found to be unable to cope with some of the more insidious seaweeds once they establish themselves at the site.

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In places like the Great Barrier Reef, Palau in Micronesia and Moorea in French Polynesia, it was discovered that corals actually avoid settling on reefs that have seaweed.

"Seaweed tends to bloom when too many herbivorous fish are fished too heavily or when agricultural fertilisers pollute rivers that run into the sea. The problems are then compounded by climate change which damages corals, making it easier for seaweeds to get a foothold. It's important for everyone that reefs don't switch from corals to seaweeds. The ability of reefs to provide fisheries will at least halve if we lose the fabulous towers and hiding places created by corals,“ said Professor Peter Mumby of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland's School of Biological Sciences.

Hence, protecting herbivorous fish is a practical way to protect the future of coral reefs. This can come in the form of legislation that regulates fisheries from catching too much fish so that sufficient fish remain to control seaweed, thus limiting the damage to reefs. Professor Mumby's team had in fact recently put forth recommendations for regulations in the Caribbean, suggesting that only 10 percent of harvestable fish are taken annually, and that all parrotfish taken be at least 30 centimetres long.