Some parts of the ocean are warming quicker than scientists ever expected. This affects everything from tiny plankton to large fish.
Not all sea creatures will suffer. Some species will thrive in warmer waters, while others will struggle to survive or vanish from certain areas.
Marine life is already stressed by pollution and overfishing. Climate change adds a new challenge: shifting habitats and disrupted food chains.
According to researchers, many fish move to stay in waters that suit them. But some, especially those needing special habitats like kelp forests, can’t easily relocate.
A UK ocean model found that while sardines might increase by 10%, mackerel could drop by 10% in the Atlantic and 20% in the North Sea.
Events like marine heatwaves rapidly change sea layers, blocking the movement of nutrients. This can weaken the entire food web almost overnight.
During a 2023 heatwave, Tom Rippeth from Bangor University warned that warmer surface waters caused stronger layering (stratification), reducing nutrient mixing.
Tiny creatures like phytoplankton feed small fish and crustaceans, which are eaten by larger fish like cod and haddock. So when plankton suffer, the entire system feels it.
According to researchers, jellyfish are increasing in the UK. They thrive in warm waters and are often a signal that the ocean food web is changing.
As the ocean warms, smaller, less nutritious plankton species replace colder-water ones in northern Europe. This weakens the energy available for fish higher up the food chain.
Due to these changes, species like bluefin tuna may become more common in UK seas. But cold-water fish like cod and herring could decline or disappear from these areas.
Climate change is reshaping entire marine ecosystems. Some fish will adapt or even benefit, but many others will lose habitat, food sources, or survival chances.
Read more at Phys.org. Winners and losers in a hotter ocean