Residents of Haikou City in China were shocked last Wednesday after noticing that a large part of Hongcheng Lake was covered with dead white and yellow fish.
According to the Chinese officials, the dead fish that belong to the herring family, were found floating ashore the lake. Collectively, the dead fish is said to weigh 35 tons.
Researchers in China are currently investigating the cause of the fish "massacre", but they believe that sudden drop in salinity levels is most likely the cause.
According to the report from USA Today, it is possible that the fish were caught up by a tidal surge and were pushed into a pumping system that led them to the lake.
Saltwater fish, such as herrings, are not adapted to a fresh water environment. In a report from Global Times, local official of Haikou City explained that if a saltwater fish accidentally end up in fresh water, their blood pressure will become higher than the water pressure causing their blood vessels to burst.
Despite the expert's explanation, many residents are still doubtful of the cause. Many still believe that piles of dead fish were most likely to be the result of pollution.
According to the report from Mashable Asia, a similar event occurred in August of last year. Tons of dead fish also floated in the Tianjin Port after toxic chemicals, such as cyanide, were introduced in the water caused by the two massive warehouse explosions in the port.
In order to prevent the nearby residents from taking some of the dead fish to be cooked or sold, health officials mobilized more than 100 sanitation workers.
Just after five hours of being deployed, sanitation workers have cleared out 20 tons of dead fish, but many kept floating into the surface.
After being scooped out of the waters, the dead fish were bagged and sent to incinerating plants and landfill sites.