Dive Asia NOW! and the Environment

Commercial Trawling

Subsurface reefs are significantly impacted by commercial trawling. Trawlers geenrally operate in deep waters where subsurface reefs and coral communities usually reside. Since large corals damage trawl nets, trawlers will try to avoid them when possible. However, more and more trawlers are using old gear or chains to remove the corals so that it is easier for them to trawl. Trawling for fish and shrimp is very common in Southeast Asia. Although it has been banned in some regions, illegal trawling is still rampant across the Southeast Asia region.

Marine-Based Pollution

Oil is one of the most common marine-based pollutants. It affects coral reproduction and growth, affecting their resilience to other pollutants. Southeast Asia is a hub for shipping traffic and oil often enters the reefs through frequent minor oil spills from ports, oil spills, ship discharge, and the maintenance of oil rigs and pipelines. On top of that, direct physical impacts from groundings and anchor damage add further stress to the corals.

Blast Fishing

Although outlawed throughout Southeast Asia, blast fishing has been practiced in most countries in the region even till today. The bombs kill fish by bursting their gas-filled swim bladders. Although some fish float to the surface, many sink and are not retrieved. A typical 1kg beer bottle bomb can leave a crater of rubble 1-2m in diameter. On top of that, regularly bombed reefs experience 50-80 percent coral mortality.

Coral Reef Bleaching

Corals are made up of three entities – the calcareous skeleton, coral polyps and the single cell algae (zooxanthellate). When stress is introduced from the environment, the algae leaves the coral, leaving the coral polyps to fend for themselves. Without the algae, corals will lose their color and turn white. This is known as coral bleaching.

With the algae gone, the corals will eventually die, taking with them the diversity of marine life that they support. The stress includes rising water temperatures caused by global warming and sediment run-off from human activities. A temperature increase of a single degree for 2 to 3 months is enough to induce bleaching in corals.

Mangrove & Seagrass Removal

Removal of mangroves and seas-grasses, which filter nutrients and trap sediments, often speeds up the problem of sedimentation and eutrophication.

Eco Tourism

Irresponsible tourism development contributes to problems such as increased garbage disposal, sewage outflows, and land-use changes. If tourism is not developed responsibly, it can destroy the very ecosystems you have come to see! As coastal areas develop, a variety of measures can be undertaken to minimize impacts on the environment.

Poison Fishing

The commercial use of poisons to capture live reef fish began in the Philippines in the 1960s and soon spread to Indonesia, Vietnam and parts of Malaysia. Although poison fishing is illegal in most of Southeast Asia, poisons are the main method used to obtain live reef fish in Southeast Asia due to difficulties in enforcement. It involves using sodium cyanide, which stuns the fish, making them easier to be captured. Unfortunately, other fish are either killed, or left exposed to predation as the poison stuns them. Exposure can cause coral bleaching and even death.

Eutrophication

Coral reefs thrive in clear tropical waters that have low nutrient levels. Coastal construction and widespread inadequate sewage treatment coupled with population growth, often results in the release of high levels of nutrients into reefs through rivers. Nutrients can initiate toxic algal blooms, smothering the corals and consuming valuable solar energy and oxygen that corals need.

Aquarium Trade

The trade in marine ornamental began in the Philippines in 1957, but has since grown into an international multimillion dollar business with Southeast Asia. Although the aquarium trade is high-valued in some areas, it is unsustainable as currently practiced. Cyanide fishing remains the main technique for fish capture in most Southeast Asian countries, although less destructive techniques such as net capture are on the rise as a result of retaining efforts.

Coral bleaching threatening Coral Triangle

by The Philippine Star – 02 Aug 2010

MANILA, Philippines – Environmentalists reported that mass coral bleaching caused by global warming is threatening the health of the Coral Triangle, a vast marine region that is home to 76 percent of all known corals in the world, including those found in the country.

Richard Leck, leader of the World Wide Fund for Nature (WWF) Coral Triangle Program Climate Change Strategy, said widespread bleaching has been reported in Anilao and Nasugbu towns in Batangas, and Taytay town in Palawan.

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Sabah Parks checking if marine parks affected

by Daily Express – 30 July 2010

Kota Kinabalu: Sabah Parks is checking all marine parks in the State for coral bleaching, Deputy Chief Minister, Datuk Seri Yahya Hussin said.

If the situation arises, Sabah Parks would close the parks or take ameliorative actions to overcome the problem.

“A few days ago, the Department of Marine Parks Malaysia announced that numerous islands in Kedah, Terengganu and Pahang have been closed for a few months due to coral bleaching.

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