Only eat oysters in months that end with R. It’s an old adage well-known to those who love the half-shell delicacy, and the reason for the legend is simple: Warmer water temperatures in the summer months often have higher levels of naturally occurring—but potentially fatal—marine bacteria. As climate change pushes water temperatures higher, however, scientists worry that the risks are rising for shellfish consumers.
A new study, have linked to sea temperatures, with cases of vibrio rising almost 200 percent each year that ocean temperatures rose one degree.
The PNAS study analyzed 50 years worth of North Atlantic plankton samples, which vibrio cling to and can later be separated from. The researchers found a direct correlation between higher water temperature and increases in vibrio infections, and were even able to show up to a quadrupling of vibrio in some areas over that time span.
While most people who get a vibrio infection will experience symptoms not unlike food poisoning (nausea, vomiting and diarrhea, among others), high-risk individuals exposed to vibrio have a 50 percent fatality rate and death can occur within two days. Conditions that make a person high risk include cancer or diabetes, but also conditions that individuals may not realize they have, such as iron overload disease or certain stomach disorders.
On Thursday, the Florida Department of Health reported that can’t be seen, smelled or tasted, the U.S. Food and Drug Administration (FDA) advises individuals that it can be impossible to distinguish a contaminated oyster from a safe one. Instead, the FDA recommends that anyone who believes they may be high-risk if exposed to vibrio say no to slurping down raw oysters and only consume the shellfish cooked.