Seawater from San Diego has reached a record of 81.3 degrees Farenheit.
The shocking temperature is the highest all-time high seawater temperature in California since daily measurements began in 1916.
It's because new research warns that & # 39; marine heatwaves & # 39; since 1982 have doubled – and will even be the same more often.
& # 39; Just as we have heat waves on land, we also have heat waves in the ocean, "said Art Miller of the Scripps Institution of Oceanography.
Between 1982 and 2016, the number of marine heat waves & # 39; roughly doubled, and likely will be more common and intense as the planet warms up, a study released Wednesday found.
Prolonged periods of extreme heat in the oceans can damage kelp forests and coral reefs and damage fish and other marine life.
& # 39; This trend will only accelerate with the greenhouse effect, "said Thomas Frolicher, climate scientist at the University of Bern in Switzerland, who led the research.
His team defined marine heat waves as extreme events where the surface temperatures were above the 99th percentile of measurements for a given location.
Because oceans both absorb and release heat more slowly than air, most marine heat waves last at least several days – and some for several weeks, "said Frolicher.
& # 39; We knew that average temperatures were rising.
& # 39; What we have not previously focused on is that the increase in the average you come across in tufts of very hot days – a shock of several days or weeks of very high temperatures, & # 39; said Michael Oppenheimer, a university climate at Princeton University. scientist who was not involved in the study.
Many zeecritters have evolved to survive in a fairly narrow band of temperatures compared to creatures on land, and even rising warming can be disruptive.
Some free-swimming marine animals such as bat jets or lobsters can shift their routines.
But stagnant organisms such as coral reefs and kelp forests & # 39; are in real danger & # 39 ;, said Michael Burrows, an ecologist at the Scottish Marine Institute, who was not part of the research  In 2016 and 2017 have stubborn high ocean temperatures from eastern Australia killed as much as half of the shallow water corals of the Great Barrier Reef – with significant consequences for other creatures that depend on the reef.  & # 39; One in four fish in the ocean lives in or around coral reefs & # 39 ;, said Ove Hoegh-Guldberg, a marine biologist at the University of Queensland.
& # 39; So much of the ocean's biodiversity is dependent on a fairly small number of the ocean floor. & # 39;
The latest research in Nature relied on satellite data and other reports of sea surface temperatures including of ships and buoys.
It did not include the recent record-breaking measurements of Scripps Pillar in San Diego – which reached 79.5 degrees Fahrenheit on August 9 – but Frolicher and Miller said the event was an example of a heat wave.
Miller said he knew something was weird when he saw a school of bat rays – which usually only collect in bags of warm water – swimming just outside the pier earlier this month.
Changes in the ocean circulation associated with warmer surface waters are likely to mean a reduced production of phytoplankton – the small organisms that form the basis of the marine food web, he said.
Marine biologists cited a patch of persistently high temperatures in the Pacific between 2013 and 2016. the Blob. & # 39;
During this period, reduced phytoplankton production led to a cascade lack of food for many species, causing thousands of Californian sea lion pups to starve, said Miller, who had no role in the nature study.
& # 39; We have repeatedly set new heat records. It is not surprising, but it is shocking, "he said.