(CNN) — A recent heatwave along the coast of northern California was too much for tens of thousand of Mussels.

Jackie Sones, a research coordinator at Bodega Marine Reserve, has worked a Bodega Bay for 15 years and has never seen a sight like this before, she says.

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“When I was approaching the field site, I could see right away that hundreds of mussels were dead,” Sones told CNN on Monday.

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As she conducted more surveys, she discovered it was not just hundreds of mussels, but tens of thousands of mussels dead along the shore. Sones has seen similar cases before where small patches of mussels die off due to heat, but she has never witnessed something this extensive.

When mussels are alive and healthy, their shells remain pressed together. When a mussel dies, those shells open up, exposing the internal tissue or an empty shell.

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California experienced a record-breaking heat wave in June, with temperatures in the north end of the state reaching triple digits.

On June 10 and 11, the high in Santa Rosa — 20 miles from Bodega Bay — was 100 degrees. The state issued a Flex Alert that day calling for voluntary electricity conservation.

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Alerts like these are only issued when outages are plaguing the electricity grid or temperatures are continuously high, according to the California Independent Systems Operator Corporation.

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Sones said mussels start to struggle physically when temperatures reach 90 degrees. In the case of these mussels, she believes they could have experienced temperatures closer to 100 degrees.