Dust from the African Desert can increase the growth of bacteria that are the main cause of food poisoning from seafood.
Researchers have found that harmful bacteria found in seawater flourish in the presence of dust that comes from the Sahara desert in western Africa, as well as other areas of continent.
They warn that as climate change causes such desert areas to grow, the risk of seafood poisoning could rise around the world.
At the same time, rising sea temperatures could further increase the chances of these bacteria occurring in shellfish caught in British waters.
Huge quantities of the dust can be carried long distances across the sea by the trade winds.
Although much of it is deposited in the Caribbean, the Gulf of Mexico and the Mediterranean, some reaches northern Europe and the UK, where it can sometimes be found forming a thin layer on car windscreens.
Dr Erin Lipp, from the University of Georgia, said that species of harmful bacteria including Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio vulnificus and even cholera showed significant growth spurts two days after African desert dust was added to the water they grew in.
She said: “We focused on desert areas in western Africa that are likely to grow over the coming century due to climate change. Dust storms in these areas are also projected to increase and with them, the transport of dust across the Atlantic Ocean basin.”
Dr Lipp, who presented the findings at the American Association for the Advancement of Science annual meeting in Washington on Saturday, added: “Our results suggest that in addition to rising sea surface temperatures, increased global production and oceanic deposition of desert dust may have a significant affect on key marine pathogens and may ultimately increase exposure rates and infection risk in humans.
“We saw a 10 to 1,000-fold growth in Vibrios, including one strain that could cause eye, ear, and open wound infections, and another strain that could cause cholera.”
Desert dust can lead to huge booms in sea life as it helps to nourish the water but the new findings could also now be used to help predict when shellfish from different regions are most at risk of causing food poisoning outbreaks.
Other research presented at the AAAS meeting also suggested that poisoning events caused by harmful algal blooms, which can release toxins that accumulate in shellfish and can be lethal to humans, will increase as the climate changes.
Stephanie Moore at the National Oceanic and Atmospheric Administration in Seattle, found that by the end of the century algal blooms would begin up to two months earlier in the year and last for a month longer than they do at present.
She said: “Changes in the harmful algal bloom season appear to be imminent and we expect a significant increase in Puget Sound and similar at-risk environments within 30 years, possibly by the next decade.
“A longer window of opportunity means that there are more days each year when shellfish beds will be closed due to harmful algal blooms.”