Parrotfish play vital role in preserving coral reefs

The new study, led by David Bellwood and Terry Hughes, both professors, and Andrew Hoey, is based on parrot fish populations on 18 coral island reefs extending from Mauritius in the Indian Ocean to Tahiti in the central Pacific.

“Parrot fish fulfil a number of key roles on the reef," explains Bellwood of the ARC Centre of Excellence for Coral Reef Studies, the journal Proceedings of the Royal Society reports.

They "remove sick and dead corals and clean areas for new corals to settle, remove weedy growth, and cart away literally tonnes of sand and sediment that would otherwise smother the corals,” explains Bellwood, according to an ARC statement.

“But there are two sorts of parrot fish -- the large ones which perform the main garbage removal task for the reef and the much smaller ones which scrape away at the reef and keep it clean, healthy and free of weed.

"Both are being targeted by fishing, but the smaller parrotfish appear better able to withstand the pressure,” adds Bellwood.

“These smaller fish are incredibly tough and this is good news, because it means they are in a sense buying us time to get the management of coral reefs right, as the world sorts out how it is going to cut its carbon emissions and reduce other pressures on reefs.”

While the smaller parrotfish are indeed resilient, it is nevertheless vital not to overfish them because of the role they perform in helping reefs regenerate, Bellwood cautions.

Larger parrotfish have already suffered extensively from heavy targetting by spear fishing.