The UK could experience a surge in endangered sharks, rays, and native oysters as species shift their habitats in response to rising sea temperatures, according to scientists.

However, some species – including a clam known as the longest-living animal on Earth – may struggle to adapt.

Researchers at the Centre for Environment, Fisheries and Aquaculture Science have, for the first time, mapped how 19 threatened marine species are expected to respond to climate change in British waters.

Many of these species may establish themselves in parts of the North Sea that are projected to become biodiversity hotspots over the next 50 years. However, climate-related disruptions could also trigger negative knock-on effects for the marine ecosystem.

In May, an intense marine heatwave raised UK sea temperatures by as much as 4°C above the seasonal norm.

“As an island nation, we’re hugely reliant on the sea for our food and for jobs. Any changes that we see in our seas are particularly impactful,” Bryony Townhill, marine scientist at Cefas, said.

The findings are intended to help guide government policy on ensuring that Marine Protected Areas (MPAs) continue to safeguard vulnerable species, even as their habitats shift.

Oceans across the world are warming, having absorbed up to 90% of the excess heat produced by the burning of fossil fuels such as oil, coal, and gas.

UK seas are particularly affected, ranking among the top 20 fastest-warming marine regions globally over the past half-century.

Fishing communities and sea swimmers have already observed the changes, with reports of jellyfish swarms close to beaches and Mediterranean species like octopus being caught in British waters.

For this study, scientists modelled two scenarios projecting changes in sea temperature, salinity, and sediment levels through to 2060. They compared these shifts in ocean conditions with the preferred habitats of 19 species currently considered vulnerable in UK waters.

The biggest beneficiaries include native oysters, basking sharks, spurdog sharks – which can grow up to 1.6 metres in length – and thornback rays, which are characterised by their spiny bodies.

In general, more mobile species are expected to adapt better, while stationary organisms are likely to face greater challenges.

One such species is the sea pen – a small organism that contributes to reef formation – which could lose up to 40% of its suitable habitat by the end of the century.

The ocean quahog, a type of clam capable of living for more than 500 years and considered the longest-living animal, is also expected to struggle.

A decline in such species may have wider consequences for ecosystems and marine food chains.

The researchers expressed surprise at some of their findings.

“I didn’t expect that native oysters would do well. Frankly, they’ve been declining and disappearing for 100 years – and yet the climate model suggests they should be doing fine and perhaps even thriving,” says Prof Pinnegar.

However, they stressed that while new suitable habitats may emerge, these vulnerable species will still require protection from threats such as fishing gear, disease, and pollution.

“We’re not necessarily promising an increase in numbers – the seas still need to be managed carefully and other pressures reduced if the creatures are to thrive in new habitats,” he says.

The movement of these 19 marine species is also likely to impact coastal communities in the North Sea, potentially leading to increased fish catches, according to Dr Townhill.

The study has been published in the journal Marine Biology.

Separately, new research by the UK Met Office, published in the  journal Weather, highlights the rapidly increasing risk of extreme air temperatures in the UK.

Scientists estimate that the likelihood of temperatures exceeding 40°C is now more than 20 times higher than it was in the 1960s – and is set to continue rising.

They suggest there is now a 50% chance of the UK experiencing another 40°C day within the next 12 years.

The UK exceeded 40°C for the first time in recorded history in July 2022, during a heatwave that caused major disruption to transport and healthcare systems.

Scientists from the World Weather Attribution group have previously concluded that such temperatures would have been “virtually impossible” without human-driven climate change.

 

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At Natural World Fund, we are passionate about restoring habitats in the UK to halt the decline in our wildlife.