|LONDON - Even traditional fishing methods can disturb the delicate balance of fragile ecosystems and are destroying some of the world\'s finest coral reefs, according to a study published on Wednesday.|
Although more intensive fishing was thought to pose a greater danger to reefs, a British team of scientists said that subsistence fishing also has an impact on reefs near the Fijian islands in the Pacific.
Until now, coral reefs were thought to be resilient to the effects of fishermen using age-old methods such as spears and hooks and lines for their catch. \"This study suggests this may not be the case and that even low levels of fishing may cause ecosystem meltdown,\" said Dr. Nick Polunin of the University of Newcastle upon Tyne in northern England.
He led a team of scientists who studied reefs near 13 Fijian islands for two years. They tracked populations of coral-eating crown-of-thorns starfish and found that even low intensity fishing of the starfish\'s predators enabled it to multiply in huge numbers and destroy the reef.
\"This paper does highlight that maybe these systems are surprisingly fragile and it is conceivable that a small amount of fishing, such as would have taken place prior to the last 50 years, could have had a significant impact in many cases,\" he added in an interview.
Crown-of-thorns starfish, which have been increasing on Australia\'s Great Barrier Reef in recent decades, are a well-known threat to reefs.
In one heavily fished area, the scientists discovered that as the starfish predators declined by nearly two-thirds the starfish population jumped from 10 per kilometer (0.62 mile) to hundreds of thousands. Meanwhile, healthy coral cover decreased by a third.
Scientists have warned that coral reefs, massive structures made of limestone that support 25 percent of all known marine species, are being destroyed but there has been debate about whether it was due to fishing or other factors.
Polunin\'s findings, which are reported in the journal Ecology Letters, suggest the ecosystems on coral reefs are quite sensitive to the impact of fishing.
Although they do not know how permanent the reef damage is, the scientists started seeing changes over two years which suggests the impact could be long-term.
\"The finding provide an additional challenge for biodiversity protection and coral reef management strategies,\" Polunin added.
Coral reefs are found in more than 100 countries and cover an estimated 109,771 square miles worldwide.
Story by Patricia Reaney
REUTERS NEWS SERVICE