(CNN) At least 35 tons of dead fish appeared in a lake in southern China, leaving residents stunned.
The piles of fish washed up in a lake in Hainan province on Wednesday, Chinese state media reported.
Residents expressed concerns on pollution, but local authorities said the fish died as a result of salinity change.
Chinese photography gets greater recognition
Liu Chengliang was shortlisted for a series titled "Bulguksa."
Maoyuan Cui was shortlisted for the 2016 Sony World Photography Awards for his landscapes in Hebei province.
Fan Li has been shortlisted twice in this year's contest and is a previous winner at the Sony World Photography Awards. This image is part of a series documenting the life of Tajiks, an ethnic minority living in Xinjiang province in China's far west.
Zhe Zhu traced the origins of the Yangtze River in his project entitled "Wind and Water," which has been shortlisted in the "Environment" category.
Yong An He focuses on wildlife and the illegal capturing of migratory birds for profit in China. He was shortlisted in the "Contemporary Issues" category.
Hui Zhang photographed Tang dynasty tombs and was nominated in the "Architecture" category.
The breeding of macaque monkeys for animal testing is exposed and explored by Li Feng, who was shortlisted in the "Environment" category.
Wang Lijun was shortlisted in the "Low Light" open (non-professional) category for this atmospheric image.
Longxiang Xie was shortlisted in the open contest for this photograph of Tibetan monks at the Langmu Temple in Gansu Province, during a heavy snowfall.
The change in salinity levels likely occurred after a tide pushed the fish up farther into Hongcheng Lake in the city of Haikou, state-run People's Daily reported.
Regional environment officials are still investigating.
It's unclear what kind of fish it was, according to People's Daily. It described it as the size of a half palm, saying residents had not seen that type of fish at the lake before.
Dozens of sanitation employees worked for hours to trash the fish, to prevent it from being sold to consumers.
CNN's Sol Han contributed to this report