Earlier last week, locals found about 300kg of dead fish washed ashore near Nghi Sơn Oil Refinery and Petrochemical complex and coastal area near Bắc Yến Hamlet of Hải Yến Commune in Tĩnh Gia District. — Photo thanhnien.vn

THANH HÓA — The blooming of algae, resulting in the red tide phenomenon, is the main cause behind mass fish deaths reported last week in central Thanh Hóa Province, the provincial People’s Committee said yesterday.

Earlier last week, locals found about 300kg of dead fish washed ashore near Nghi Sơn Oil Refinery and Petrochemical complex and coastal area near Bắc Yến Hamlet of Hải Yến Commune in Tĩnh Gia District.

Nearly 50 tonnes of fish bred in cages of fishermen on Nghi Sơn island commune of the same district also reportedly died.

An investigation by local authorities showed that seawater samples near the port of Nghi Sơn Oil Refinery and Petrochemical complex and around floating cages of Nghi Sơn Commune were a reddish brown colour. Tests revealed a type of alga named Hairoi-Creratium furca bloomed, causing the red tide.

The provincial People’s Committee has ordered Tĩnh Gia commune authorities to continue to supervise the situation and warn locals to move cages away from the affected water area.

Locals have also been advised to harvest the unaffected fish early to reduce further losses and destroy the dead ones, rather than use them for daily meals or animal feed.

The provincial People’s Committee has proposed that Prime Minister Nguyễn Xuân Phúc order the Ministry of Natural Resources and Environment and Ministry of Agriculture and Rural Development to send scientists and specialists for fact finding and to instruct the affected locality to deal with the incident.

Seawater observation along coastal areas near the Nghi Sơn Oil Refinery and Petrochemical complex must be added to the national environmental observation programme, the committee suggested.

A similar incident occurred in the province’s Mã River in mid August this year with the reason behind blamed on alluvium, mud and soil brought down by floods.

In May, more than 17 tonnes of fish being bred in cages in the province’s Thạch Thành District died. A large amount of wastewater from cassava starch and sugar plants released in the nearby Hòa Bình Province without proper treatment had caused the mass fish deaths. — VNS