Damaging trawl fishing has been banned in more than 100 square miles of seabed off Sussex to help once-vast kelp forests recover.
A new bylaw has been approved to prohibit trawling year-round over large areas along the entire Sussex coast closest to the shore, to help habitats regenerate and improve fisheries, Sussex Inshore Fisheries and Conservation Authority (IFCA) said.
Wildlife groups hope the move, which they say will protect 117 square miles (304 square kilometres) of the coastal seabed, will help with “rewilding” the sea by allowing the underwater seaweed forests to regenerate.
It follows a campaign to protect kelp which was supported by Sir David Attenborough, who has described the approval of the new bylaw as a “landmark decision” for the management of UK coastal waters.
Sir David said: “Sussex’s remarkable kelp forests will now have a chance to regenerate and provide a home for hundreds of species, creating an oasis of life off the coast, enhancing fisheries and sequestering carbon in our fight against climate change.”
The broadcaster and naturalist also described the new protection as a “vital win” in the fight against the nature and climate crises, ahead of a major international climate summit, Cop26, being hosted by the UK later this year.
The long seaweeds that grow in forests in the coastal sea provide a vital habitat, feeding ground and nursery for seahorses, cuttlefish, lobster, seabream and bass, boosting wildlife and commercial stocks.
The kelp forests can also lock up huge amounts of carbon in the fight against climate change, improve water quality and reduce coastal erosion by absorbing the power of the waves.
As recently as the 1980s, extensive, dense kelp beds stretched 25 miles (40km) along the West Sussex coast between Shoreham-by-Sea and Selsey Bill and at least 2.5 miles (4km) out to sea.
But campaigners warn they have dwindled to almost nothing as a result of storm damage, trawling and the dumping of sediment by dredging boats.
Although a number of factors could be stopping the kelp from re-growing, the implementation of the near-shore trawling bylaw relieves that pressure on the area where the kelp grows, giving it a chance to recover, they said.
The bylaw has been approved by the Environment Department (Defra) after it was first agreed by the Sussex IFCA in January 2020, following a public consultation.
Deputy chief fisheries and conservation officer for Sussex IFCA Dr Sean Ashworth said: “We are delighted that the local community and central government have recognised the critical importance of looking after Sussex marine wildlife and the local fisheries that critically depend upon it.
“We look forward to seeing a regeneration of the lost kelp forests and an associated improvement of the inshore fishery.”
The move is being hailed as a milestone for the Help Our Kelp partnership, whose campaign was supported by Sir David as well as MPs and members of the public.
Henri Brocklebank, chairman of the Help Our Kelp partnership and director of conservation at Sussex Wildlife Trust, said: “The support of Sussex communities and our elected representatives has been inspirational.
“It shows us the passion that exists for restoring our marine ecosystems and recognising the value that they give to all of us, from food to the protection of our coastline.”
Charles Clover, executive director of the Blue Marine Foundation, said: “We welcome the signing of the Sussex bylaw, as it is a recognition by Government that rewilding the sea is a way to protect marine biodiversity, invest in inshore fisheries and store carbon at a single stroke.
“We believe the Sussex kelp forest will now show the benefits of removing damaging fishing gears from vast areas around the UK coastline and offshore.”
Scientists and volunteer divers have been collecting baseline data on the remaining small pockets of Sussex kelp, to enable measurement of the positive change that could come out of the bylaw, experts said.