About four tonnes of rubbish is washing up on Hac Sa Beach every day, according to a statement from the Marine and Water Bureau.
This is more than double the usual amount, Macau Post Daily reports.
Officials say the problem is being caused by rainfall and flooding in the upper regions of the Pearl River Delta, sweeping trash downriver to Macao. Easterly winds are also blowing more refuse than normal onto the beach.
[See more: Your guide to recycling stations in Macao]
While daily cleanups are made at Hac Sa Beach – the better-known of Macao’s two beaches – rubbish has been a longstanding problem.
Illegal dumping and poor waste management in Pearl River Delta communities are to blame, environmentalists say, with much of the waste found in local waters consisting of single-use plastic.
Macao banned non-biodegradable disposable plastic straws and stirrers last year, following on from a ban on styrofoam food containers in 2021. Activists say the bans are not enough.