WASHINGTON -- Even the seas are seeing heat waves.

A new study finds the number of "marine heat waves" roughly doubled between 1982 and 2016. Scientists say such events will likely become more common and intense as the planet warms.

Prolonged periods of extreme heat in the oceans can damage kelp forests and coral reefs, and harm fish and other marine life.

The study published Wednesday in Nature relied on satellite data and other records of sea-surface temperatures including from ships and buoys.

Earlier this month, scientists recorded all-time high seawater temperatures off the San Diego coast since readings began in 1916. While the event wasn't part of the latest study, researchers say it was a marine heat wave.