Sharks & Oysters Set to Thrive in Warmer UK Waters: Climate Boom or Ecological Warning?

As climate change warms UK coastal waters, an unexpected ecological shift is unfolding: both sharks and oysters may find the seas more hospitable. Recent UK research suggests that rising sea temperatures and improved habitat conditions could bring a boom in habitats suitable for basking sharks and native oysters—alongside warnings for less adaptable species.

🌊 A Warmer Climate Means More Habitat

A major climate impact study led by the Centre for Environment, Fisheries and Aquaculture Science (Cefas), supported by the Joint Nature Conservation Committee (JNCC), models future marine habitats around the UK. The study—covering 20 vulnerable marine species, including sharks and shellfish—projects rising sea temperatures (+0.25°C to +0.4°C per decade), salinity shifts, and sediment changes .

Crucially, it forecasts that species such as the basking shark and native oyster will enjoy a considerable increase in “suitable habitat” by 2100. The North Sea and central UK waters are expected to become ecological hotspots for these species .

🦈 Sharks on the Move

Already, around 40 shark species—including basking, blue, thresher, and mako—are recorded in UK waters. A June 2025 update from the Marine Conservation Society highlights sightings of shortfin mako, basking, blue, common thresher, and Greenland sharks off the UK coast .

Longer-term, warming seas may allow southerly shark species—blacktip, sand tiger, and possibly hammerheads—to expand northwards. While great whites have only unverified sightings, changing conditions could enable occasional visits . Some experts caution sightings are sporadic: deep-swimming individuals might already be present without detection [oai_citation:0‡carbonbrief.org](https://www.carbonbrief.org/factcheck-will-climate-change-bring-great-white-sharks-to-uk-waters/?utm_source=chatgpt.com).

🦪 Oysters Rebound in Northern Seas

Native oysters, heavily impacted by overfishing and pollution, may also benefit. The Cefas-JNCC analysis suggests suitable conditions for oysters will improve, particularly in the central and northern North Sea, enabling potential habitat recovery .

Oysters act as “ecosystem engineers”: filtering water, recycling nutrients, and strengthening coastlines. If populations rebound, the ecological and commercial payoff could be significant.

📉 Mixed Outcomes Across Species

The climate-driven boost isn't uniform. Some habitats will still see declines—ocean quahogs, sea fans, slender sea pens, and fan mussels face shrinking suitable ranges due to warming and sediment changes .

Species' fortunes depend on adaptability, mobility, and water conditions. Migratory sharks with wider thermal tolerances will likely fare better than slow-moving or rigid species.

🔧 What This Means for Conservation

• Marine protected zones must adapt to shifting habitats, protecting both expanding and declining species.
• Monitoring programs like the shark tagging initiative remain vital to confirm new arrivals and guide policy .
• Shellfish restoration efforts—such as native oyster reef revival—could be turbocharged by warming, provided pollution and fishing are controlled.
• Public education is key: warming seas don’t equal danger. Most sharks pose little threat, and native oysters support healthier marine ecosystems.

Conclusion: A Sea of Change

Climate change is reshaping UK marine ecosystems. While some species gain ground, others retreat. Sharks and native oysters may thrive—but only if careful management ensures ecological balance. These changes present both conservation opportunities and challenges. If harnessed wisely, warming seas could spur a resurgence of life in UK waters.