Grey seals, minke whales and bluefin tuna: is the North Sea bouncing back to its glory days?

From the outside, the Tunny Club looks like any other seaside fish and chip shop. A short walk from Scarborough harbour, only the photos of John Wayne and Errol Flynn on the wall betray the shop’s fleeting history as a global centre for big-game fishing.

In the 1930s, film stars and the ultra-wealthy flocked to the Yorkshire seaside resort for their chance to catch the enormous bluefin tuna – known as “tunny” – lurking off the North Sea coast. In 1933, aristocrat Lorenzo Mitchell-Henry reeled in what remains the largest fish ever caught in British waters: a 386kg bluefin tuna.

Steam-powered yachts filled the bay on the hunt for even larger fish. “The bluefin tuna were coming into the North Sea to feast on the enormous shoals of herring and mackerel that were there. They would be followed by whales and dolphins,” says Tony Juniper, chair of Natural England. By the 1950s, however, the warm-blooded aquatic torpedoes had mostly disappeared, exposing a greater decline in the health of the North Sea ecosystem.

The North Sea’s chalk reefs, sea grass meadows and shallow waters are home to a huge array of life, including internationally important seabird colonies. But centuries of overfishing, pollution, oil and gas exploration and the climate crisis have degraded the seas between Britain, Scandinavia and western Europe, driving declines in wildlife.

Overfishing of herring resulted in an estimated 97% biomass decline from the 1950s to the 1980s, according to one study, which found populations have since made a modest recovery. North Sea anglerfish and cod are among fish populations in a “deeply troubling state”, a 2023 report found, while demersal fish – species living close to the sea floor – have declined by 23% since 1993, according to the state of nature 2023 report. But in recent years, a bounceback in some wildlife has given conservationists reason for cautious optimism.

“The North Sea is one of the most pressured areas of ocean on planet Earth. There are relatively few other places that have a combination of industrialised countries around a largely enclosed sea, intensive agriculture, and pressures from fishing going back centuries. But the wonderful thing about nature is that it can recover pretty quickly if you give it the chance,” says Juniper.

The North Sea was one of the most productive in the world which is why we’ve seen so much extraction over the centuries
Kirsten Carter, RSPB

Bottlenose dolphins, along with humpback and minke whales, have been spotted in greater numbers in recent years along England’s North Sea coast, monitoring groups say. Their reasons for returning are not entirely clear. Grey seals – once in danger of disappearing around the UK – are flourishing. Visits to colonies on Norfolk beaches – where thousands of pups are born every year – have become a Christmas ritual for local people. Around the beach at Horsey, nearly 4,000 seal pups were born last year during a record-breaking season.

“We know the grey seals are doing well, which is fantastic news, and we know that’s also true of other species in the North Sea,” says Bex Lynam, marine advocacy manager for North Sea Wildlife Trusts. “Bottlenose dolphins – which we weren’t seeing off the Yorkshire coast until the last five years – have been recorded in a huge number of sightings. It’s clear they have enough food. They are also calving down here, which is fantastic,” she says.

Lynam credits the impact of growing protections for nature in the North Sea, such as new marine protected areas and increased controls on fishing. In April, the UK and Scottish governments announced a ban on commercial sandeel fishing in the North Sea in an effort to help other marine species recover. Sandeels are a leading food source for puffins, kittiwakes and other bird species, many of which are suffering significant population declines. They are also a food source for many of the fish humans regularly eat. This ban is being contested by the EU.

“I think what we are seeing is some of the benefits of some of the legislation that’s been put in years ago,” says Lynam. “The EU’s common fisheries policy put catch limits on some fish species. While they’re not as ambitious as we might like to see, having been in place for decades now, I think we are starting to see the recovery to some fish stocks. It is undoubtedly helping the wider marine environment,” she says.

With the expansion of offshore wind infrastructure already signalling a new industrial era in the North Sea, conservation groups have cautioned that they could present a new challenge to wildlife. But others are daring to imagine the species that could return with strengthened conservation measures, for example orca, salmon and even the bluefin tuna.

“The North Sea was one of the most productive seas in the world, which is why we’ve seen so much extraction over the centuries,” says Kirsten Carter, head of UK marine policy with the RSPB.

“[But] we did have big species living off our coast in mass quantities. Currently, everyone gets excited when we see one whale, a few dolphins … Seeing things in mass numbers is something that we’ve lost. We normalise what we are seeing now. But things can be different,” she says.

This article by Patrick Greenfield was first published by The Guardian on 9 January 2025. Lead Image: A minke whale breaching – they have been sighted in growing numbers in recent years along England’s North Sea coastline. Photograph: Tom McDonnell/The Wildlife Trusts/PA.

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