A Marine Heat Wave Intensifies, with Risks for Wildlife, Hurricanes and California Wildfires

A Marine Heat Wave Intensifies, with Risks for Wildlife, Hurricanes and California Wildfires

SOURCE: Inside Climate News DATE: September 18, 2019 SNIP: An intensifying marine heat wave in the northeastern Pacific Ocean has triggered government warnings about harm to salmon and other fisheries along the U.S. West Coast, and it’s raising concerns about hurricane risks to the Hawaiian islands and wildfire risks in California. The current marine heat wave covers a horseshoe-shaped area about the size of Alaska. It extends from the Gulf of Alaska down the coast of Western North America and westward to Hawaii. In the warmest areas, sea surface temperatures have reached about 5.4 degrees Fahrenheit above average. Marine heat waves occur when sea surface temperatures in part of the ocean rise and stay above the expected seasonal temperatures for at least five days in a row. Scientists say these heat waves are forming more frequently, and they suspect that shifts in winds and ocean currents driven by global warming are a big part of the cause. A 2018 study showed that, since 1925, marine heat waves have become 34 percent more frequent and they are lasting longer. The majority of marine heat waves, about 87 percent, can be attributed to human-caused global warming, the authors found. The National Oceanic and Atmospheric Administration is tracking the current marine heat wave and has warned of disruptions to ocean ecosystems and fisheries along the West Coast. Andy Leising, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, California, said this year’s warm blob could be as strong as the last and is already one of the most significant marine heat waves on record in the region because...
New marine heat wave resembles killer ‘Blob’ that devastated sea life on West Coast, NOAA says

New marine heat wave resembles killer ‘Blob’ that devastated sea life on West Coast, NOAA says

SOURCE: Seattle Times DATE: September 5, 2019 SNIP: A new marine heat wave has formed off the West Coast that is similar to “The Blob” that devastated sea life and ravaged runs of Pacific salmon. Although the similarities are striking, whether the new system will cause the same havoc is yet to be seen. Like The Blob, which formed in 2014 and peaked in 2015, the new mass of warm water emerged over the course of a few months. A persistent weather pattern has becalmed winds that typically stir up the ocean’s surface to keep it cool. The heat wave is relatively new and right now mostly has affected the upper layers of the ocean. If weather patterns shift, it could break up rapidly, according to the National Oceanic and Atmospheric Administration (NOAA). “It looks bad, but it could also go away pretty quickly,” said Nate Mantua, a research scientist at NOAA’s Southwest Fisheries Science Center in La Jolla, California, in a news release Thursday. The Blob upended the West Coast marine ecosystem, resulting in the deaths of millions of animals, from seabirds to sea lions. Salmon runs cratered, adding to the stress on animals that eat them, including endangered southern resident killer whales. The new expanse of unusually warm water is eerily similar: It has quickly grown in much the same way, in the same area, to almost the same size, stretching from roughly Alaska to California. It is the second-largest marine heat wave in terms of area in the northern Pacific Ocean in the last 40 years, after the earlier Blob. About five years ago, sea temperatures...
Climate change: Marine heatwaves kill coral instantly

Climate change: Marine heatwaves kill coral instantly

SOURCE: BBC DATE: August 9, 2019 SNIP: Increasingly frequent marine heatwaves can lead to the almost instant death of corals, scientists working on the Great Barrier Reef have found. These episodes of unusually high water temperatures are – like heatwaves on land – associated with climate change. Scientists studying coral after a heat event discovered that extreme temperature rises decayed reefs much more rapidly than previously thought. The study revealed that corals became up to 15% weaker after an extreme heat event, causing some fragments to actually break off from the reef. Dr Tracy Ainsworth, from the University of New South Wales in Australia, worked on the study. She told BBC News that her whole research team, made up of scientists who have worked on corals for more than a decade, was shocked to find them to be “really brittle”. More typically, temperature rises cause something called coral bleaching – when the coral expels vital algae that lives in its tissues. In those events, the coral itself remains intact. “But what we’re seeing here is that – when the coral tissue dies – it falls and breaks away from the skeleton,” Dr Ainsworth explained. Commenting on the paper, Dr Laura Richardson, from the School of Ocean Sciences at Bangor University, UK, said that the really significant discovery was “the rapidity with which the reef skeleton breaks down when you have these severe heatwaves”. Dr Richardson added that the team had documented, for the first time, that severe heatwaves were causing “almost instant mortality of corals”. Dr Ainsworth said the researchers referred to the resulting, heat-damaged skeletons as “ghost corals,...
Surprise! Unexpected ocean heat waves are becoming the norm

Surprise! Unexpected ocean heat waves are becoming the norm

SOURCE: The Daily Climate and PNAS DATE: August 6, 2019 SNIP: Ocean heat waves, which can push out fish, plankton and other aquatic life, are happening far more frequently than previously thought, according to a study published today in the Proceedings of the National Academy of Sciences. “Based on historical and lived experience, people expect certain conditions to prevail in the ecosystems they depend upon. Climate change is now introducing strong trends that push conditions beyond historic levels,” the authors wrote. Led by the Gulf of Maine Research Institute, researchers looked at 65 large marine ecosystems around the world over the past 164 years to determine how frequently “surprising” ocean temperatures occur, with surprising defined as an event expected to occur about two times in 100 years, lead author and chief scientific officer at the Gulf of Maine Research Institute Andrew Pershing told EHN via email. Pershing and colleagues reported that over the past seven years, the planet averaged 12 ecosystems each year experiencing the kind of unusually warm temperatures that someone in the given region would expect to see only a couple times in a century. In 2016 alone there were 23 such events. “Across the 65 ecosystems we examined, we expected about six or seven of them would experience these ‘surprises’ each year,” Pershing said in a statement. The results are in line with what scientists continue to warn: oceans are the Earth’s largest heat collector. According to the National Oceanic and Atmospheric Administration, more than 90 percent of Earth’s warming over the past 50 years has happened in the...
Heatwave cooks mussels in their shells on California shore

Heatwave cooks mussels in their shells on California shore

SOURCE: The Guardian DATE: June 29, 2019 SNIP: In all her years working at Bodega Bay, the marine reserve research coordinator Jackie Sones had never seen anything like it: scores of dead mussels on the rocks, their shells gaping and scorched, their meats thoroughly cooked. A record-breaking June heatwave apparently caused the largest die-off of mussels in at least 15 years at Bodega Head, a small headland on the northern California bay. And Sones received reports from other researchers of similar mass mussel deaths at various beaches across roughly 140 miles (225km) of coastline. While the people who flocked to the Pacific to enjoy a rare 80F (27C) beach day soaked up the sun, so did the mussel beds—where the rock-bound mollusks could have been experiencing temperatures above 100F at low tide, literally roasting in their...