Brighton: Fears sediment dumped in the sea is smothering wildlife

Sussex Wildlife Trust, residents and a councillor want to put a stop to Brighton Marina disposing of dredged sediment in the Beachy Head West Marine Conservation Zone between the marina and Ovingdean.

Brighton Marina needs to dredge the entrance to the harbour to ensure boats can keep moving.

But those concerned about the activity’s impacts on sea life including blue mussel beds, native oysters and short-snouted seahorses, say the material should be disposed of further out to sea, it is currently disposed of about 50 metres out, and have called for people to object to Premier Marina’s application to renew its dredging licence.

People are concerned about the potential harm the sediment is causing (Image: Jay Butler)

The company has held the licence for ten years and the renewal ahead of its expiration in May 2025 would allow it to have a further ten.

The original licence was granted before the area was made a conservation zone.

Independent councillor for Rottingdean and West Saltdean Bridget Fishleigh, who objects to the licence renewal, said she had met with the company, who had told her there was “nothing to worry about”.

She said she was told that disposing of the material further out to sea would take longer and would cost more money.

“We can see black debris washed up on the beach,” she said.

“There’s brown sludge in the rock pools.

“The impact on sea life and for humans swimming isn’t known.”

Sarah Ward, marine conservation officer at Sussex Wildlife Trust, said the activity should not continue.

“The licence was originally granted before the MCZ was designated but now that the area is protected, it’s not appropriate to allow this potentially harmful activity to continue,” she said.

Residents have noticed a decline in marine life (Image: Jay Butler)

“Sussex Wildlife Trust disagrees on principle that such an activity should be allowed to take place in a protected area and we’re also concerned over the precedent this may set for similar cases elsewhere.”

Ms Ward said the trust has serious concerns about how the site is monitored.

“In our view, the monitoring is inadequate and fails to address the impacts of sediment movement and potential for smothering,” she said.

“Smothering can cause all sorts of issues for marine life, but in this context the main concern is the community of organisms that live on the chalk bedrock – many of these are sessile filter feeders. This means they are unable to move away if the water gets silted up and may struggle to obtain the nutrients they need from the surrounding water.

“Many reports by the local community and fishing industry have noted increased siltation in the intertidal zone and this has not been addressed.”

She said there are other disposal sites in the nearby area which could be used instead.

Resident Jay Butler used to take children rock pooling in the area, however he has had to stop because it has become “too dangerous” due to the silt making the chalk ledges slippy.

He also said it became “pointless” due to dwindling crab numbers.

A boat disposing of sediment (Image: Jay Butler)

He described the sediment as “toxic”, “thick sludge”.

“Over the summer (for the last ten years), hundreds of tonnes of silt have been dumped daily between Brighton Marina and Ovingdean Gap,” he said.

“I have fished local beaches for 45 years. Every angler I know with similar experience laments the fact that fish stocks have declined.

"Sewage outfalls, runoff from roads and agriculture (herbicide use) are all contributing to the problem.

“The only solution is to dump further out to sea. Stopping dredging altogether, would render the marina inaccessible due to siltation - a major blow to the local economy.”

A public consultation is underway and people have been encouraged to register their views.

Premier Marinas Brighton was approached for comment but did not respond.