Hong Kong cleaned up almost 90 tonnes of palm oil from Lamma Island after a collision between two ships in the Pearl River Delta estuary spilled the substance ashore, Reuters reported. The accident is believed to have taken place on August 3.

At least 13 beaches have been closed since Sunday as environmentalists and residents worried about the ecological consequences of the harmful substance. Plastic bottles, dead fish, shells and rocks among many other things were found to be coated with palm oil on the beaches. The congealed palm oil looked like clumps of snow blanketing the beaches.

The Hong Kong government said it had deployed helicopters and ships to collect the waste, AP reported. Several workers were present at the beaches using blankets to contain the substance.