Sussex kelp explained: what five years without trawling has done

Since 18 March 2021, trawling has been banned from 304 square kilometres of seabed off the Sussex coast, from Chichester in the west to Rye in the east. Five years on, the Sussex Kelp Recovery Project says mussel beds are growing and local fish stocks are increasing.

What was lost

Kelp is a large, flat-edged brown seaweed. In the 1950s kelp forests off Sussex stretched up to 4km out to sea, and they once ran for 40 kilometres along the coast, giving shelter and food to cuttlefish, lobster, black sea bream and bass. A single kelp can support up to 80,000 living organisms. Kelp beds can also absorb up to 70% of the energy of waves, which helps protect beaches and cliffs from storms.

From the 1980s, storms, marine heatwaves, poor water quality and repeated trawling of the seabed took their toll. By 2019 just 4% of the kelp forests of the 1980s remained.

How the ban happened

Sussex Inshore Fisheries and Conservation Authority (Sussex IFCA) drafted a nearshore trawling byelaw in 2019. A campaign called Help Our Kelp backed it, with a short film by the local production company Big Wave, narrated by Sir David Attenborough. Blue Marine Foundation³, one of the campaigners, says 2,500 members of the public supported the byelaw. It is one of the largest of its kind in the UK.

The campaign then became the Sussex Kelp Recovery Project, 11 organisations co-ordinated by Sussex Wildlife Trust^1,2. They include Blue Marine Foundation, the Zoological Society of London, Sussex IFCA, Adur & Worthing Councils, Sussex Underwater, Big Wave Productions and the universities of Sussex, Brighton and Exeter, and Queen Mary University of London.

Letting the seabed recover

The project’s approach is to stop the damage and follow the natural recovery of the seabed, which Sussex Wildlife Trust calls rewilding. Kelp is only part of it. Mussel beds and chalk reefs could recover too, and they also give shelter to marine life.

Scientists are tracking the change. After the ban, a University of Sussex⁴ team began yearly surveys at 34 sites between Shoreham and Selsey, using baited underwater cameras, water samples tested for DNA and sound recordings. Blue Marine also runs crab and lobster surveys with local small-scale fishermen.

What has changed so far

Black sea bream and blue mussels are already increasing, Sussex Wildlife Trust says, but “nature takes time to recover”. In its five-year update the trust wrote that “96% of one of the most biodiverse ecosystems on Earth won’t recover overnight”.

Trawling is not the only pressure. Blue Marine says high levels of sediment from land run-off and the disposal of dredged material can cut the light kelp needs to grow.

How to get involved

The project asks people who spend time on the shore, in the waves or under the water to get involved, from raising money and awareness to collecting data. Sussex Wildlife Trust’s project page has details, and also asks for donations to help the kelp recover.