High temperatures are leading wild mussels to essentially cook themselves, marine experts say.

In California, for instance, Vice reports that a large number of mussels are dying. Many of the dead mussels were found attached to rocks, where it's already warmer, and it's believed they were "steamed to death in their own shells."

One expert told Vice it's the largest die-off of mussels she's seen in more than a decade.

When highs are around 75 degrees, for example, the temperature inside a mussel can easily reach 105.

The deaths won't just affect the mussel population, according to Vice. They also impact other sea creatures in the underwater ecosystem.

Expect more of the same in the coming years, says California research Jackie Sones.

“Climate scientists believe that the frequency and duration of heat waves is going to increase,” she told Vice. “From that perspective, although it’s hard to predict the future, it’s important to document these extreme weather events and their impacts.”

The average mussel lives for about two years, according to Wild Coast, although some species have life a span of up to 50 years. They're often served with, or in place of, clams and oysters.