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Coral reefs in southern Taiwan becoming less diverse

2012/09/11 22:08:33

Taipei, Sept. 11 (CNA) Coral reef communities in waters around Kenting, southern Taiwan, have slumped by over 63 percent in the past 26 years due to climate change and bleaching, Taiwan's top research institute said Tuesday.

The coral reefs in waters around Kenting's Wanlitung region decreased from 47.5 percent in 1985 to 17.7 percent in 2010, with biodiversity there becoming what Chen Chaolun, a research fellow at the Academia Sinica's Biodiversity Research Center, described as "monotonous."

Since 1996, the reefs around Kenting have been in decline as a result of typhoons, particularly Typhoon Morakot in 2008, as well as global sea-surface temperature-related worldwide coral bleaching that started coming to attention in 1998, Chen added.

From 1999 to 2005, during which there were no major disturbances, coral cover managed to return to 1987 levels.

Coral species from the genera Acropora and Montipora have almost disappeared from the reefs, whereas corals belonging to the genera Favia and Heliopora have maintained their presences at steady levels, which has resulted in fewer habitats for other species in the coral ecosystem, Chen said.

The disappearance of hard corals indicates that the health of the area's coral reefs is in jeopardy and that diverse reefs are declining, he went on.

"When a city changes, the citizens there change as well. With overfishing, now what snorkelers see is only a vast area of coral reef covered by green algae," Chen described of the underwater scene after macro algae, which competes with coral for space, increased from 11.3 percent in 2003 to 28.5 percent in 2010.

The researchers also found that hard coral in the region, which usually grows in shallow waters and is more vulnerable to pollution, has not regenerated, while the Heliopora and Favia corals return to a certain coverage rate several years after climatic disturbance.

Nearly 300 types of coral grow in the waters around Taiwan, which are home to nearly 1,500 fish species. However, natural disasters that are increasingly harder to control, plus human damage, are severely affecting the local coral reef ecosystem, Chen warned.

He urged the government to make Kenting National Park an ecological preserve in which fishing is prohibited, since many human activities do irreversible damage to coral communities.

Coral reef communities are also economically beneficial, with the annual net income provided by coral reefs globally estimated at up to NT$1 trillion (US$29.8 billion), according to Chen.

The government should tell local fishermen that a fishing ban "does not mean to stop you from living your lives as before. It aims to help you live better lives," he said.

Currently, Taiwan has only two "no-fishing" zones -- the Penghu Islands and the Pratas Islands, but the ban has not been implemented comprehensively and fishing continues in Penghu, Chen added.

"If things continue like that, we can only say goodbye to Taiwan's coral."

(By Chen Chih-chung, Zoe Wei and Kendra Lin)