≡ Menu

Study says clay an effective tool to control red tide

By Mediatrix P. Cristobal

MANILA, Feb 26 — The onslaught of El Nino has ravaged coasts in four provinces in the country, prompting the issuance of red tide advisory but a study said red tide spread can be minimized, if not fully eradicated.

A University of the Philippines Marine Science Institute team led by Dr. Rhodora Azanza conducted laboratory tests revealing clay can actually "paralyze" algae blooms that cause red tide.

The team used ball clay to control the growth of Pyrodinium bahamense var. compressum and they found out that the clay particles flocculate the suspended organism in the water, making it settle at the sea bottom and it becomes inactive.

It is also not harmful to the environment, hence there is no significant adverse effects in water quality and marine life, their study said.

The prevailing El Nino triggered algae blooms in Dumanquillas Bay in Zamboanga del Sur, Sorsogon Bay, Sorsogon; Bislig Bay in Bislig City, Surigao del Sur, and Murcielagos Bay in Zamboanga del Norte and Misamis Occidental.

The Bureau of Fisheries and Aquatic Resources (BFAR) have already issued an advisory on red tide, stating consumption of shellfish from these areas may suffer from paralytic shellfish poisoning (PSP) can cause death.

Early symptoms of PSP include tingling of the lips and tongue, which may begin within minutes of eating poisonous shellfish, or may take an hour or two to develop.

Red tides have occurred in the country since 1983 in Maqueda Bay, Samar and are presently being monitored by the Bureau of Fisheries and Aquatic Resources in 27 sites.

The Philippine Council for Aquatic and Marine Research and Development (DOST-PCAMRD)-supported study was done to test a similar research by Korean on the dilemma caused by same marine phenomenon when drastic changes in temperature hit their seas.

The PCAMRD said while monitoring and warning systems are in place to avoid human fatalities in areas where they occur, there have been no mitigating measures here that have been applied in the past.

Researchers of South Korea's National Fisheries Research and Development Institute have found that application of 8 grams of clay per liter of water in “red tide” – stricken waters proved to be effective in reducing populations of the dinoflagellate Cochlodinium polykrikoides (which can cause fish kills at high densities) by 80 percent.

Koreans found that the use of clay at 0.5 gram per liter of water reduced the population of the organism suspended in the water from 95 percent to 51 percent.

Dinoflagellate Pyrodinium bahamense var. compressum is one of the type of algae blooms that intoxifies mussels, fish and other sea creatures. These filter the algae from the water and cause human mortalities when consumed. (PNA)V3/MPC

{ 0 comments… add one }

Leave a Comment