"Red tide" not to blame for mass fish death: Vinafis

By Pham Huong   April 29, 2016 | 02:34 pm GMT+7

A "red tide" is not to blame for the colossal number of dead fish that have washed up along Vietnam’s central coast, said the Vietnamese Fisheries Society (Vinafis) on Thursday.

Vinafis, whose mission is to promote the development of the fisheries sector, also asked the government to clearly identify the number of discharge pipes off the coast of Ky Anh in the central province of Ha Tinh.

The Vietnamese government told the media on Wednesday that there are two possible causes of the mass fish deaths. The first is the impact of toxic chemical substances discharged by humans on land or at sea. The second is a natural phenomenon known as a “red tide”. The government also said there is no proof to conclude that wastewater discharged by Formosa, a Taiwanese steel plant, is the cause of the mass fish deaths.

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A huge number of fish have washed up in central provinces. Photo by Duc Hung

In a letter sent to the government and related ministries, Vinafis agreed that the fish deaths was caused by toxic substances, and ruled out the possibility of a “red tide”, a natural phenomenon when harmful algae bloom at an abnormal rate and produce powerful toxins.

“No key features of this phenomenon, which include algae turning the water a deep red, mass fish deaths near the surface and huge amounts of dead algae washing ashore, have been recorded,” said Vinafis in the letter.

When a “red tide” occurs, masses of algae die and decompose. The decaying process can deplete oxygen in the water, causing the water to become so low in oxygen that marine creatures die.

According to Vinafis, poisonous chemical substances discharged by humans seem to be the most likely reason for the disaster, so the next step is to identify the substances.

As of April 25, around 70 tons of fish had washed up on four of Vietnam's coastal provinces.

Vinafis put three questions to the government: the number of discharge pipelines in Ky Anh; the use of 300 tons of chemicals substances imported by Formosa; and test results of seawater near discharge pipes as well as the chemical residue left in the dead fish.

“If test results prove that toxins are not to blame for the death of huge numbers of fish, then wastewater discharged by factories in Ky Anh is not to blame and we'll have to continue the investigation in a different direction.”