More than 150 volunteers took part in the annual World Oceans Day cleanup at Kalk Bay Harbour this weekend, making it the largest turnout in the event's nine-year history. Divers and community members removed rubbish from the harbour and shoreline while contributing to one of Cape Town's most detailed records of coastal pollution.

This weekend, more than 150 people joined the annual World Oceans Day cleanup at Kalk Bay Harbour, making it the biggest in the event's nine-year history.

Kalk Bay Harbour is one of the oldest working harbours in South Africa. With its colourful fishing vessels it is an iconic place, known to locals as a place to get fresh yellowtail after a strong southeaster.

What remains hidden is what accumulates beneath the surface. Rubbish is blown in from the harbour moorings, or washed down through the stormwater drains, settling on the sea floor out of sight.

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For nine years, a team of volunteers has been coming together to clean it up, both in the water and on land.

The beach cleanup was organised by Sentinel Ocean Alliance. Trail Freedivers provided the backbone of the underwater cleanup. Twenty divers set off into the water, orange mesh buoys keeping them visible, while allowing the collection of rubbish such as fishing lines, plastic cutlery and plastic wrappers that have settled on the seafloor and stay there.

On land, about 50 people came through Waves for Change alone, many of them young surfers from Ocean View and Lavender Hill who traded their Saturday surf for...