Volunteers cleaning up the Thames foreshore on Friday and Saturday won’t be getting their feet wet—they’re waiting till the tide is out.

The Thames 21 environment charity is calling for volunteers to ‘deep clean’ the riverbed along the Isle of Dogs loop that acts as one of the river’s natural collection points for flotsam and jetsam floating downstream.

“It is one of the worst areas for plastic bag litter,” explained the charity’s Debbie Leach. “There are layers of plastic bags beneath the river’s surface continuing to pose a threat to wildlife.”

Plastic bags have collected at the river bend for years, weighed down by sand and currents where they break down into ever smaller, toxic pieces.

Volunteers who are being joined by Poplar & Limehouse MP Jim Fitzpatrick have already removed more than 330,000 bags from the stretch of river since 2001.

They also pick up bits and pieces like old bicycle frames—and even found a firearm one year which police hurriedly took away for examination.

The volunteers meet at Poplar Rowing Club in Ferry Street, Cubitt Town, 8.30am to 11.30am on Friday, and at Newcastle Drawdock in Glenaffric Avenue nearby at 9am to 12 noon on Saturday, equipment provided by the charity.