USA Today reported that more than 100 workers were dispatched to clean up the 35 tons of dead fish, which floated into a lake in Haikou, China, Wednesday.
Authorities are still scratching their heads over what killed the fish, which washed up in truckloads.
The fish floated to the surface of the Hongcheng lake, located in the Hainan island, China’s southernmost point. The government is investigating the cause of their death, but experts speculate that it might be due to fluctuations in the water’s saline levels, reports China Daily.
A researcher with the Haikou Oceanic and Fishery Bureau, Lu Yongliang, said the fish came from the larger Nandu River, and were swept into the Hongcheng lake with the tide, where they died from the sudden drop in salinity.
The saltwater fish are not meant to thrive in freshwater; more water is forced to enter their bodies from the freshwater lake, causing their blood vessels to rupture, Chinese researchers explained.
Despite the experts’ statements, the public has been skeptical and are speculating that the fish have died from pollution, and this isn’t the only major fish kill across the world – recently the Indian River Lagoon made national news.