25 Aug 2016 История Экосистемы

This fish's appetite could save coral reefs – if we learn to curb ours

Sandy, white beaches and bountiful coral reefs are inextricably linked to the image of the Caribbean. Today, both are under threat because of our taste for the beak mouthed, rainbow coloured parrotfish.

It is estimated that as much as a half of all Caribbean coral reefs were lost since the 1970s. And the future looks bleak for the remaining 50 per cent, which could disappear in the next 20 years, stifled by overgrown algae.

The loss of grazers, such as the parrotfish and sea urchins, is a key driver of coral decline in the region, according to the Status and Trends of Caribbean Coral Reefs: 1970-2012, a report by the Global Coral Reef Monitoring Network, the International Union for Conservation of Nature and UN Environment.

The parrotfish spend up to 90 per cent of their days grazing on the overgrowth of algae on corals, helping to maintain a healthy ecological balance between the two groups of organisms. As they go along, they chip away the calcium carbonate exoskeleton of corals with their beak-shaped mouths. These bits of corals are released back to the environment as fish droppings and are deposited as sand on the famous white Caribbean beaches. A single parrotfish can produce hundreds of kilograms of sand throughout its lifetime, making it invaluable to the tourism industry.

For years, the parrotfish, commonly found in the shallow tropical waters of the Caribbean and Indian Oceans, have been consumed at unsustainable rates. Today, conservation and fisheries management strategies are urgently needed to preserve these beautiful fish and the marine ecosystems they help to maintain.

A report by the Proceedings of the National Academy of Sciences of United States found that corals can remain resilient if less than 10 per cent of fishable parrotfish biomass is harvested and a minimum size of 30 centimetres is implemented.

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Recently, the private sector has joined the call for action to reduce parrotfish exploitation and to restore its population. Last July Sandals Resort International launched the “Save the parrotfish, save our islands” campaign.

That move followed an announcement by the Jamaican Rainforest Seafoods of their intention to stop the sales of parrotfish. The company also revealed a $1.25 million partnership with the University of the West Indies Alligator Head Marine Lab to implement protective measures against reef fish population depletion and to inform local residents about sustainable fishing practices.

UN Environment is working, through its Caribbean Office, with the Youth for Sustainable Development Movement in Jamaica to promote an appreciation for the country’s beaches, educate Jamaicans on the importance of parrotfish to the island's marine ecosystems and exploring the possibility of harvesting lionfish as a substitute for parrotfish. The lionfish is an invasive species with significant impact on coral reef fauna due to its voracious appetite for small fish.

Listing parrotfish in the Protocol on Specially Protected Areas and Wildlife in the Wider Caribbean Region of the Cartagena Convention is an especially helpful legal tool to promote sustainable management of the fish in the region.

While measures to limit parrotfish captures are vital to protecting coral reefs, it is also important to offer alternative livelihoods for those that may be affected by the restrictions. UN Environment recommends engaging with indigenous and local communities and other stakeholders to communicate the benefits of such strategies for coral reef ecosystems, for the replenishment of fisheries and for livelihoods of communities.