Heat waves don’t just occur over land. They can also happen in our oceans and last for long periods.

What is a marine heat wave?

NOAA defines a marine heat wave as, “any time the ocean temperature is above the 90th percentile for a specific length of time. This means that the temperatures are warmer than 90% of the previous observations for a given time of year.”

Currently, scientists are observing warmer ocean waters in the Gulf of Mexico and the Caribbean Sea and say it could last for several more months.

How this affects us

One way marine heat waves affect us is if tropical systems pass through the warm waters, they can strengthen, which could cause problems if these stronger storms make landfall.

These heat waves can also cause coral to lose algae, which help supply the coral with food. After long periods without algae, the coral can die. Coral reefs help shield coasts from storms and floods, not to mention provide homes for marine wildlife.

(Pexels/BelleCo)

NOAA states that coral will like die if, “the corals experience ocean temperatures of 1°C greater than the historical maximum monthly average for two months, or 2°C greater than the historical maximum monthly average for one month.”

Marine heat waves can also change migration routes for marine wildlife, cause algae blooms near the shore, and kill off crabs and fish that fisheries depend on.

Click here to read about “The Blob,” a marine heat wave that lasted years and caused devastation.

Can we do anything about it?

Meteorologists can forecast these marine heat waves now, which help prepare communities for what might come. 

Making small changes in our everyday lives can also help cut out greenhouse gases that contribute to the warming.

Our team of meteorologists dives deep into the science of weather and breaks down timely weather data and information. To view more weather and climate stories, check out our weather blogs section.