OYSTER

OYSTER POPULATION WIPED OUT BY RECENT FLOODS
Source: New Strait's Times World News 18/02/2007 14:32:33

The entire population of oysters at the mouth of Sungai Muar has been wiped out by the recent floods.

The farmers who raised them in cages along the 1km coastal belt from Parit Tiram to Jalan Ismail, and the part-time divers, are now without income from harvesting the oysters.

Breeder/diver Azman Hassan says it will take at least two years for the oysters to return to the river.

The 67-year-old said that before the disaster, at least 50 part-time oyster divers were bringing up the catch each day.

He said Muar is known for two types of oysters - one from the Muar river and another variety found among coastal rocks, harvested by the women with hammers and chisels.

Muar oysters are in demand, he said, because they are believed to cure gallstones, and because they are sweeter and more succulent than oysters from other areas.

The shells are also used to make decorative items but at the moment, the sale of shells has been stopped. They are being dumped back in the river to encourage the oyster spate to grow, said Azman.

He said oyster farming along the Muar river began last July and was a huge success.
But the floods destroyed over a million oysters in 5,000 cages, causing an estimated loss of RM140,000.

He said the farmers plan to try again when the water in the river gets back to normal.

Even restaurant owners are feeling the pinch, as many of their customers refuse to eat “imported” oysters. Not only are they more expensive at RM14 to RM16 per kilogramme, but also lack the unique flavour and texture of Muar oysters.

Oyster-frier Lim Ah Hing says Muar oysters are touted as the best in the country.

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Global warming and pollution could doom oysters
American Physiological Society
October 10, 2006

Oysters exposed to high water temperatures and a common heavy metal are unable to obtain sufficient oxygen and convert it to cellular energy, according to a new study presented at The American Physiological Society conference, Comparative Physiology 2006.

The study showed how cadmium, a heavy metal, reduces the oyster's tolerance of warmer water temperatures and makes it more vulnerable during the summer when water temperatures rise. Half of the oysters exposed to the pollutant in 28° C (82° F) water died within 20 days, said lead researcher Gisela Lannig. Oysters exposed to cadmium at lower temperatures showed much lower mortality rate, suggesting that the combination of high temperature and cadmium is more stressful than each of these conditions alone, she said.

The study "Temperature tolerance in the oyster, Crassostrea virginica, is affected by cadmium," was carried out by Lannig, of the Alfred Wegener Institute for Polar & Marine Research, Bremerhaven, Germany, and Jason Flores and Inna Sokolova, of the University of North Carolina at Charlotte. The work was done in North Carolina. The researchers presented the study October 10 during a poster session at Comparative Biology 2006: Integrating Diversity in Virginia Beach.

Oyster population decimated

Oysters once thrived in the coastal regions of much of the eastern United States, but over-fishing, global warming, rising ocean water temperatures and increased pollution have combined to reduce the oyster population to 5% of what it was 200 years ago, Sokolova said. The loss of oysters has far-reaching environmental implications.

"We can't even imagine the expanse of oyster reefs 100-200 years ago and their impact on the ecosystem," Sokolova said. For example, a century ago, the oyster population could completely filter the water in the Chesapeake Bay in three days. Today, with the oyster population continuing to decline from poor water quality and disease, it would take a year to filter the same amount of water, she said. In addition to filtering water, oysters create a kind of reef that other marine life depends upon.

"Studies have shown that there are more than 300 species reliant on oyster reefs, including at least 12 species important for their commercial or recreational value, such as blue crabs, sheepshead, croaker and stone crab," Sokolova said. "Some of these species, such as blue crabs, use oyster beds and reefs as nursery areas and as feeding grounds." The oyster beds are also important to a variety of marine life that serves as food for larger fish. It was within this context that the North Carolina team did their study.