New bacteria found in UK waters due to rising sea temperatures

‘Increasing abundance and diversity of Vibrio bacteria creates health risks,’ study says

Vibrio bacteria was found in shellfish samples from Chichester Harbour (Getty Images/iStockphoto)

New bacteria species have been found in sea around the UK as warmer waters lead to “growing diversity” in their family, according to a new study.

Researchers warned this could lead to health risks for humans, with some Vibrio bacteria causing illness – such as stomach bugs if eaten in raw or undercooked shellfish – and skin infections.

The study, led by the University of Exeter, found UK waters were seeing a greater diversity of this species and even detecting two strains – Vibrio rotiferianus and Vibrio jasicida – for the first time.

“Vibrio species can often be found in UK waters in summer, when temperatures are more favourable for them,” said Dr Sariqa Wagley, one of the study’s authors.

“With sea-surface temperatures rising due to climate change, Vibrio activity in the waters is more common, and the diversity of Vibrio species is now increasing.”

The study, published in journal Water Research, said this has led to a “worldwide surge” of infections linked to this virus in humans and acquatic animals.

It looked at sea surface temperatures around the UK to identify conditions that would be favourable for Vibrio bacteria to live and grow.

Researchers then collected samples of shellfish from four sites used by the industry and tested them for Vibrio bacteria.

Species that can cause illness in humans were detected in samples from three of these: Chichester Harbour, Osea Island and Whitstable Bay.

Dr Wagley said: “Increasing abundance and diversity of Vibrio bacteria creates health risks not only for people eating seafood, but for those using the sea for recreation purposes – either due to swallowing infected seawater or from the bacteria entering exposed wounds or cuts.

“Vibrio bacteria are also a threat to a variety of marine species including shellfish themselves.”

Authorities in the US said last year a bacteria species from the Vibrio family was behind numerous instances of dead fish washing ashore or floating in waterways.

A man also died after being infected by a rare Vulvio bacterium in the US in 2018.

Dr Wagley said the latest UK study’s findings support the “hypothesis that Vibrio-associated diseases are increasing and are influenced by the rise in sea-surface temperature”.

She added: “We need to monitor this situation closely, to protect human health, marine biodiversity and the seafood industry.”

Dr Luke Helmer, from the Blue Marine Foundation, said: “The impacts of climate change on the marine environment are likely to be widespread.

“Understanding how these changes will affect ecologically and commercially important species and the people that rely on them will be crucial moving forward, in order to mitigate against them.”