Report to the Prime Minister on the unusual fish deaths in Thanh Hoa sea

On September 10, Vice Chairman of Thanh Hoa Provincial People's Committee Nguyen Duc Quyen signed an official dispatch to the Prime Minister, reporting on the unusual fish deaths along the coast of Tinh Hai and Nghi Son communes, Tinh Gia district.

Fish in cages in Ngoc Island Bay, Nghi Son Commune, Tinh Gia District died en masse and were picked up by fishermen on September 8 - Photo: HA DONG

News from the Office of the Thanh Hoa Provincial People's Committee said that the content of the dispatch clearly stated that on the morning of September 7 and 8, the Thanh Hoa Provincial People's Committee received information from the leaders of Tinh Gia district reflecting on the situation of wild fish in the sea and fish raised in cages of local people dying abnormally in Tinh Hai and Nghi Son communes.

Cage fish and sea fish all died.

Through investigation and verification by the authorities, it was found that from September 5 to 6, while fishing in the nearshore waters behind the Nghi Son Refinery and Petrochemical Plant project, 300 - 500m from the shore, fishermen in Tinh Hai commune discovered a number of seafood species (such as flounder, catfish, crabs...) dying abnormally and drifting ashore.

According to statistics from the People's Committee of Tinh Hai Commune, the amount of dead seafood collected was about 100kg. The People's Committee of the Commune has collected and buried the dead fish.

At around 7am on September 8, in the fish cage farming area of ​​Nghi Son commune, there was also a phenomenon of fish farming in cages struggling in the water and dying very quickly in large numbers. The incident happened simultaneously in the fish cages, in which many fish cages died completely.

According to statistics from Nghi Son Commune People's Committee, the number of affected households is 21/66 households with 207/1,391 cages, the number of dead cage fish is up to 47.45 tons, including grouper, snapper, sea bass, and red snapper.

After receiving news that fish in cages had died unexpectedly, the Nghi Son commune government and the professional agencies of Tinh Gia district asked the people to move the fish cages that were not dead away from the reddish-brown water mass, and instructed the fishermen to collect the dead fish and destroy them according to regulations.

On the same day, September 8, at the coastal area of ​​Bac Yen village, Hai Yen commune, Tinh Gia district, people discovered dead natural fish drifting ashore.

The total amount collected by the people was about 200kg, including flounder, catfish, crabs... The Commune People's Committee collected and buried these dead fish.

By September 9, the reddish-brown water had drifted ashore and there were no more deaths of caged fish.

Waiting for final results

In recent days, the People's Committee of Thanh Hoa province has directed the Department of Natural Resources and Environment to coordinate with relevant units to conduct a survey at sea from Lach Bang fishing port (Hai Binh commune) to Nghi Son commune.

The inspection showed that there were scattered dead fish floating on the sea, the quality of the sea water on the surveyed route had a normal color. However, in the Nghi Son Refinery port area, the sea water was reddish brown.

The entire fish cage farming area of ​​Nghi Son commune has a darker reddish brown seawater with lots of suspended sediment. The above seawater phenomenon is relatively consistent with the description of fishermen in Tinh Hai commune when they discovered a large patch of reddish brown seawater at sea when catching seafood.

At the time of inspection, the Department of Natural Resources and Environment collected seawater samples from the area where the fish died in cages, the port area of ​​Nghi Son Refinery and Petrochemical Plant, and nearshore seawater and sent them to the Hai Phong Institute of Marine Resources and Environment for implementation.

The preliminary analysis results are as follows:

Water samples taken at the area where fish cages died (Nghi Son commune): discovered Hairoi algae - Creratium furca blooming causing red tide with a density of about 8 million cells/1 liter of seawater.

Water samples taken at the port area of ​​Nghi Son Refinery and Petrochemical Plant: detected the algae species Ceratium furca also dominant, but with a lower density, about 500,000 cells/liter of seawater.

Thus, it can be initially determined that the cause of the above-mentioned deaths of wild fish and cage-raised fish is due to the impact of the Hairoi algae - Creratium furca in seawater, which has an outbreak of high density on a large scale (also known as algal bloom).

This phenomenon occurs for many different reasons, but the main cause for the sea areas of Tinh Hai and Nghi Son communes is the large amount of organic matter in the mainland flowing into the river mouth with rainwater into the sea.

The remaining seawater quality analysis results and fish samples (sampled and analyzed by the Veterinary Department, Department of Agriculture and Rural Development of Thanh Hoa) are currently awaiting final results.

Thanh Hoa Provincial People's Committee proposed that the Prime Minister direct the Ministry of Natural Resources and Environment and the Ministry of Agriculture and Rural Development to send experts and scientists to conduct field inspections to determine the specific cause of fish deaths; provide guidance on how to handle the phenomenon of algal blooms; and add a coastal water quality monitoring point in the port area of ​​Nghi Son Refinery and Petrochemical Plant to the annual national environmental monitoring program network of the relevant sector.

According to TTO