San Diego’s coast experiencing a marine heat wave, Scripps researchers find – NBC 7 San Diego

Scientists at Scripps Institution of Oceanography at UC San Diego say a marine heat wave has pushed ocean temperatures well above seasonal averages off the Southern California coast for months, raising concerns about impacts on marine ecosystems and wildlife.

Researchers at Scripps Pier say the long-term average from November through April is from 58 to 63 degrees, with the coolest ocean water at the end of December through March. This year, the warmest temperatures recorded were in February and mid-March through mid-April. During that time, Melissa Carter, director of the Shore Stations Program at Scripps Institution of Oceanography at UC San Diego, says that’s when daily sea surface temperature records were being broken. Recently, she says many of these temperatures have been trending 3-7 degrees above average.

For more than a century, researchers at Scripps Institution of Oceanography have collected sea-surface temperature samples from Scripps Pier.

On Thursday, Carter demonstrated the mechanisms used to collect daily temperature readings from the pier, which showed a reading of about 20 degrees Celsius, or nearly 70 degrees Fahrenheit. “So it’s reading 20 degrees Celsius, almost exactly, which is almost exactly 70,” Carter said.

Researchers say the Pacific Ocean is currently experiencing a marine heat wave, which occurs when sea-surface temperatures remain above the 90th percentile for more than five days. It’s not only San Diego’s ocean waters that are experiencing these anomalies, but it’s also being recorded up and down California’s coast.

According to Scripps scientists, this event has lasted for more than three months. Data collected at Scripps Pier shows that 38 daily temperature records have already been broken this year.

“What we’ve seen over the last few years is that these marine heatwaves we can have extreme temperatures that can come out of these persistent high-pressure systems that last in the North Pacific,” Carter said.

Scientists say those persistent high-pressure systems can weaken winds and reduce the movement of nutrients to the ocean surface, affecting marine food supplies.

Tammy Russell, a marine seabird expert at Scripps, said seabirds have been washing up on beaches and dying from starvation. Russell says they are testing negative for avian flu, and that it could be the warmer water making it more difficult for them to find food since the fish they rely on live in cool ocean water.

“My reaction to this is that it’s really awful, potentially for our ecosystem if warming continues,” Carter said.

Researchers say forecasts calling for El Niño conditions this summer could allow the marine heat wave to continue. “We’re still seeing warmer temperatures off our coast and in Baja now connecting with those warmer temperatures at the tropics, which then, that’s the concern for driving these warm temperatures throughout summer,” Carter said.

This story was originally reported for broadcast by NBC San Diego. AI tools helped convert the story to a digital article, and an NBC San Diego journalist edited the article for publication.