Plastic pollution and global warming are combining forces to disrupt ocean life – Bangor University research

New Bangor University research has revealed that the combined effects of ocean warming and microplastic pollution could severely damage marine ecosystems, with global consequences for the planet’s climate and food security.

In controlled experiments mimicking future ocean conditions, scientists found that phytoplankton – microscopic organisms responsible for producing half the world’s oxygen and capturing vast amounts of carbon – suffered significant losses in both growth and diversity when exposed to both higher temperatures and projected microplastic levels.

Diatoms, a key group of phytoplankton and major carbon fixers, were particularly hard hit.

‘Hostile environment’

Dr Abi Cousins, who conducted the study as part of her PhD at Bangor University, said: “The climate and plastic crises are not separate issues – they’re deeply connected.”

“Together they could create a hostile environment for the very organisms that help stabilise our planet’s climate. If phytoplankton suffer, we all do,” Dr Cousins added.

The findings suggest that this dual threat could reduce the ocean’s ability to sequester carbon by over 10 billion tonnes a year – a third of annual current fossil fuel emissions.

But the study also points to hope in the form of Nature-based Solutions (NbS).

Seagrass

When seagrass fronds were added to the experimental setups, phytoplankton fared far better.

Seagrasses appear to trap microplastics, preventing them from harming marine life.

Co-author Professor Christian Dunn, from Bangor University said: “This is a wake-up call, but also a call to action.

“We need urgent global action to cut plastic pollution and carbon emissions – but we must also invest in restoring ecosystems like seagrass meadows. They’re not just beautiful and full of marine life; they’re frontline climate defenders.

“The research highlights the urgent need to tackle interconnected environmental crises together – and to recognise the powerful role nature can play in the fight back,” Prof Dunn said.