Warming seas might be making us sicker. Researchers have found that Vibrio bacteria — small organisms that can cause lethal infections such as cholera in humans — have become more abundant in coastal regions of the North Atlantic as water temperatures increased over a 50-year period. And that change might be responsible for an "unprecedented" rise in human infections, scientists say.
The increase in Vibrio bacteria is substantial. The report, published yesterday in Proceedings of the National Academy of Sciences, shows that since 1958, their numbers have doubled or tripled in certain coastal areas that have also grown warmer. And during that same period, the rate of human infections along the coasts of North America and Northern Europe also increased, reports The Washington Post.
Vibrio bacteria infect both fish and humans, and the results aren't pretty. Some bacterial species can cause cholera, whereas others poison people through their food, causing symptoms like diarrhea, fever, and chills. And this happens a lot; Vibrio bacteria are responsible for around 80,000 illnesses and 100 deaths in the US each year, according to the CDC. So, having more of these little critters in coastal waters probably isn't a good thing.
To obtain these results, the scientists analyzed water samples collected over a period of 54 years at nine coastal sites in North America and Europe. In all but one of those sites, the researchers found that Vibrio bacteria thrived and became more abundant as waters warmed. Because of this, the researchers suggest that sea-surface temperature data taken from satellites could be used to predict outbreaks — and plan a response — before they happen.