A A huge ecological experiment begins today on Dogger Bank, a section of sunken landmass that once formed a bridge between Britain and mainland Europe. Trawling and dredging – fishing activities that not only collect fish and shellfish, but also plow up plants and animals from the seabed – are now banned, at least on the British part of this Atlantis of the North Sea.

Protecting 12,000 sq km of seabed, 100 km off the east of England, where early humans hunted woolly mammoths, amounts to an act of rewilding thousands of times larger than the garden “the Best in Exhibit’ at this year’s Chelsea Flower Show. Covering an area almost the size of Northern Ireland, it marks a turning point in the health of our neighboring seas.

Until today, this officially designated marine protected area was just a “paper park” – a term used to describe a place protected in theory but not really in practice – hammered by dredges targeting scallops and beam trawlers harrowing the seabed in search of sole. Nobody really knows what will happen next, but history gives us an idea of ​​what Dogger Bank might look like again. In the 1830s, small sailboats could catch a ton of halibut a day. Today, vessels fishing across the Bank – in UK, Danish, German and Dutch waters – land less than two tonnes of halibut a year. Slow-breeding monsters such as halibut simply don’t have enough time to breed and grow before being caught.

Halibut aren’t the only missing megafauna. There’s a photo of a huge sturgeon caught on Dogger Bank in 1925 on the wall of a Lowestoft pub. One day the sturgeon may be back, along with the halibut and perhaps the oysters recorded along the south side of the bank in the 1880s. These restored plant and animal communities will enhance the sea’s ability to absorb carbon. The possibilities are wildly exciting.

What we know from Lyme Bay on the south coast of England, where trawling and dredging were banned in 2008, is that four times the number of commercially valuable fish have returned, as have four times the total number of species. The result of banning the most damaging fishing gear – not fishing itself – has been an economic and ecological success. Why, you may ask, don’t we manage all our coastal waters this way?

The success of Lyme Bay belies rumors of the “displacement” of the industrial side of the fishing industry, particularly in the Netherlands. The reality is that the protection of the Dogger Bank probably does not mean the concentration of fishing in fewer places, but more fish to be caught by ‘angling’ outside the protected area. The revival of fish habitat and fish stocks will soar – provided the government steps up and properly protects the roughly 70 other ‘paper parks’ in UK offshore waters, which is not in no case a certainty.

The protection of Dogger Bank is a rare thing: a Brexit dividend. There are several ironies to this, however. The Dogger was nominally protected a decade ago by the UK government under the EU Habitats Directive – drafted by the Prime Minister’s father, Stanley Johnson, when he was an EU civil servant. Then nothing happened, because there is an unnecessary conflict in European law between nature conservation and the common fisheries policy which has not yet been resolved.

When the Common Fisheries Policy ended in UK waters after Brexit, ministers from the Department for Environment, Food and Rural Affairs were – our charity had to remind them – obligated to uphold the nature laws we inherited from Europe. There was no longer any conflict of rights.

George Eustice, the environment secretary, boasted that by protecting Dogger Bank, Britain was using its post-Brexit freedoms to protect the marine environment. But then he did something awful earlier this year, proposing in a green paper to scrap all obligations on ministers to protect natural sites, sea or land. Reassuringly, there is opposition to his ideas on all sides, and they are far from becoming law.

The protection of the Dogger Bank is nonetheless a great achievement. It’s a sign, amidst the gloom, that we can begin to tackle the biodiversity crisis and climate emergency by boosting the ocean’s capacity to absorb carbon. Among these positive and hopeful developments are the creation of a ‘blue belt’ of marine protected areas around certain British Overseas Territories, the protection of the kelp belt off Sussex and the recovery of the bluefin tuna, which is now returning off Great Britain, Ireland and Norway. after decades of absence.

I just wish we could count on our government to follow the latest example of ambitious science-based management. Because, unlike bluefin tuna, two-thirds of fish stocks in UK and EU waters – including cod, the country’s favorite fish – are currently fished at levels above scientific advice. Shocking and bad decisions continue to be made every day, when we could be promoting the recovery of overexploited species and reducing carbon emissions at the same time.

We need to rethink how we manage the oceans in times of climate crisis. The ocean is the greatest carbon sink on Earth, and it can help us by absorbing far more carbon than it currently does. All we have to do is roll the dice against the smokestack maritime industries – trawling, dredging and other industrial fishing methods – which have already devastated our waters and which scientists now tell us are causing so many emissions than the world’s aviation industry.

We can rewild the sea. It’s already happening, not just on Dogger Bank. It works and – here’s the thing – in the end, everyone wins.