Authorities from the neighboring city of Zhuhai called for closer cooperation between Hong Kong and various mainland cities to combat marine pollution in the Pan-Pearl River Delta area.

The call came after an unprecedented amount of rubbish was seen on Hong Kong's shorelines, mainly in Cheung Chau, Lantau Island and Stanley, in the past few weeks, according to local environmental concern groups.

Hong Kong residents have taken to social media to vent their anger and share images of beaches strewn with household and other waste. They have called on the government to take action and express Hong Kong people's concerns about the alleged source of the rubbish - nearby mainland cities.

An initial investigation conducted by mainland marine experts showed that the rubbish came from the sea area from Wanshan town in Zhuhai. The busy water was occupied by six of the busiest regional sea routes. This brought a large amount of rubbish during marine vessel operations, according to a statement by the Wanshan government.

The monsoons and ocean currents had also brought marine refuse from the Pacific Ocean. This had contributed to the accumulation of garbage on shorelines near the area, according to the release, specifically when there are northeastern or southeastern winds. This increased the difficulties of the sea-cleaning work, the release said.

Meanwhile, as the Wanshan water is one of the most active fishing grounds in China, the fishing operation had also brought rubbish to the area, the release said.

Thus the town's authority called for a higher level of authority to coordinate joint marine supervision and a cleaning mechanism between Hong Kong and mainland. This is to better stop marine pollution in the water.