Marine heatwave in Pacific Ocean moves closer to coast

A marine heatwave that has developed offshore in the Pacific Ocean has moved closer to shore, according to the National Oceanic and Atmospheric Administration (NOAA).

The heat wave has reached the coast of Washington and Oregon, according to NOAA, which is a U.S. government organization. The maps the organization has shared showing the heatwave also show it has reached the west coast of Vancouver Island as well.

Maps by NOAA's California Current Marine Heatwave Tracker showing how far above normal temperature the water is off the coast of Oregon, Washington and B.C. on July 30. (NOAA)The same map one week later on Aug. 6. (NOAA)

These marine heatwaves increase the potential for harmful algal blooms, reduced fish size and abundance, and negatively affect marine habitats.

NOAA is monitoring for these potential impacts.

The organization says there have been large marine heatwaves in the eastern north Pacific Ocean for most of 2023, but have remained far offshore, until now.

“We now know more about marine heatwaves and how they affect the ocean,” said Andrew Leising of the Southwest Fisheries Science Center. “This can help us anticipate and look for ways to reduce the negative impacts they may have.”

In previous years, marine heatwaves has led to closures for shellfish harvesting due to the algal blooms which cause a risk to the public, according to NOAA.

The emerging El Niño weather pattern indicates the heatwave will begin to impact the west coast by spring 2024, with increasing affects on ecosystems and marine life particularly down south by California.

“Ocean temperatures keep breaking records,” NOAA says in a post on its website. “The movement of the marine heatwave near the Northwest Coast comes as the world’s oceans are as warm as they have ever been since modern records began. While the emerging El Niño pattern contributes to the warming, the oceans also absorb much of the excess heat from climate change.”

The California Current Integrated Ecosystem Assessment, which is a NOAA program, says there have been large marine heatwaves each year between 2019 and 2022. Each of those four years have been the 2nd, 3rd, 6th, and 4th largest marine heatwaves for the eastern North Pacific respectively since monitoring began in 1982.

Animation of the progression of the 2020 marine heatwave courtesy of California Current Integrated Ecosystem Assessment:

Editorial Policies Report an Error