Fishing should be banned in almost a third of UK seas to help stocks recover from decades of harm, campaigners say.
The Co-operative Group wants 30% of UK waters to become “no-take” reserves by 2020 to reverse decades of overfishing.
It says just eight out of 47 fishing stocks are healthy and warns once-common species now face extinction.
The campaign, backed by the Marine Conservation Society (MCS), calls for the measures to be included in the government’s Marine Bill.
The Co-operative’s Marine Reserves Now campaign aims to help wildlife recover from overfishing and habitat destruction.
Spokesman Paul Monaghan said: “The need for an extensive network of marine reserves around the UK is an uncomfortable truth.
“In UK waters there are 22 species – such as the common skate and Atlantic halibut – listed as critically endangered.
“Most worryingly, the rate of biodiversity loss is accelerating, highlighting the need for quick and decisive science-led action,” he said.
Other once-common species facing extinction include the angel shark, sturgeon and leatherback turtle.
Dr Jean-luc Solandt, the MCS’s biodiversity policy officer, said: “Marine reserves are a cost-effective way to achieve benefits for wildlife and the fish species that rely on habitats being protected for the long term. it makes social, economic and ecological sense.”
He said the recently published Marine Bill puts a duty on ministers to create marine conservation zones, but does not indicate protection levels.
In terms of recovery and sustainability, it was “window-dressing”, he said.
The Marine and Coastal Access Bill, aimed at helping wildlife thrive in biologically diverse seas, is due to have a second reading in the Lords this month.
The Royal Commission on Environmental Pollution recommended four years ago that 30% of UK seas be protected as marine reserves closed to commercial fishing.
There are two highly protected marine reserves – off Lundy Island, in the Bristol Channel and Lamlash Bay, in Scotland.
The MCS also wants protection for specialist areas like sea grass beds and reefs.
Around 10% of Lyme Bay, in Dorset, was permanently closed this summer due to the damaging effects of scallop dredging and bottom trawling on reefs, corals and rare sponges.