Aquaculture and Fisheries News => Aquaculture News => ข้อความที่เริ่มโดย: Nicaonline ที่ มกราคม 15, 2007, 11:27:22 AM

หัวข้อ: Malaysia; Red Tide strikes caged fish
เริ่มหัวข้อโดย: Nicaonline ที่ มกราคม 15, 2007, 11:27:22 AM
Source: Daily Express  World News    14/01/2007 15:23:15


Fish farmers in the West coast are advised to be vigilant as red tide algae Cochlodinium polykrikoides have killed caged marine fish in Pulau Gaya, said Boniface Jintoni, Head of Research Unit at the Sabah Fisheries Department.


A caged 40kg giant groupa at Gaya had died while some others are dying, he said. For the moment, however, the problem is site specific and not found elsewhere.


Analysis of water samples collected at the site showed a concentration of 4,500 C. polykrikoides cells per litre water in the affected Pulau Gaya fish farm. To allay panic Jintoni said C. polykrikoides algae is harmful only to fish and not humans. "The current problem has nothing to do with paralytic shell fish poisoning," he pointed out. Paralytic poisoning is caused by an entirely different algae called Pyrodium bahamense which produces a neural toxin and that is very dangerous to man," Jintoni said.


Affected fish in the current case apparently choke to death and not by the release of a toxin. The algae block the gills and affected fish die from asphyxiation.


Fish farmers in the West coast are, thus, advised to be very watchful of the situation, as a bloom can be devastating. One cage fish farmer in Tuaran reportedly lost half a million ringgit worth of high value commercial species during a C. Polykrikoides bloom in 2003. C. polykrikoides is a known red tide specie associated with extensive fish kills and economic loss in Japanese and Korean waters. Marine scientists believe that physical contact rather than a released toxin, is the cause of death of fish or oysters during such red tide bloom.


However, no bloom has been observed in Sabah waters at the moment," Jintoni said. "It was found only in Pulau Gaya's ocean front side so far," he noted.


As a precaution, the Director of Fisheries Department, Rayner Stuel Galid, has instructed all fisheries officers in Kota Kinabalu, Papar, Tuaran and Kota Belud to alert marine fish farmers, Jintoni said.


The Department is carrying out intense monitoring of the situation.


In Sabah, this ichthyotoxic "red water" bloom species tends to surface at the end and the beginning of the year, Jintoni said. However, shell fish are not affected, Jintoni stressed. "The public must not be confused." Meanwhile, C. polykrikoides is an unarmoured, marine, planktonic dinoflagellate species" with a distinctive spiral-shaped cingulum, according to a Sabah fisheries department release.


It is a photosynthetic species which reproduces asexually by binary fission.


It is a cosmopolitan species found in warm temperate and tropical waters.


It was first reported from the Carribean sea along the southern coast of Puerto Rico and has since been reported in northern Atlantic waters along the American east coast.


It is widely distributed in the northwestern Pacific waters along the coasts of Japan and Korea.

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