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...
Global Warming Is Hitting Ocean Species Hardest, Including Fish Relied on for Food

Global Warming Is Hitting Ocean Species Hardest, Including Fish Relied on for Food

SOURCE: Inside Climate News DATE: April 24, 2019 SNIP: Sea creatures, especially those that live in shallower water near the coasts, are much more vulnerable to global warming than land animals, new research shows. The scientists found that local populations of marine animals are disappearing at double the rate of land-based species. That’s because marine animals like fish, crabs and lobster are already more likely to be living near the threshold of life-threatening temperatures, and because in the ocean, there are fewer places to hide from extreme heat, said Malin Pinsky, lead author of a new study published Wednesday in the journal Nature. “These results are stunning, in part because the impacts of climate change on ocean life were virtually ignored just a decade ago,” said Pinsky, an ocean researcher at Rutgers University. The study took a close look at cold-blooded marine species whose body temperatures are dependent on their surroundings. “We already know terrestrial species are highly vulnerable to climate change,” he said, “and now we see that marine species are even more vulnerable.” “We’re heading into uncharted territories. We’re already seeing species disappear from places they’ve been for generations and longer,” Pinsky said. For example, damselfish and cardinalfish, two small species that live on coral reefs, already live near their thermal limits and have started to disappear from some areas, which contributes to the overall decline of coral reef health. Of the marine species they studied, 56 percent experienced a range contraction due to global warming, compared to 27 percent of the land species. Fish species won’t be able to evolve fast enough to keep up, so...
Turtles’ absence from Nicaraguan stronghold raises alarm for future

Turtles’ absence from Nicaraguan stronghold raises alarm for future

SOURCE: The Guardian DATE: April 15, 2019 SNIP: Every year, from November through March, leatherback sea turtles arrive to the secluded shores of the Río Escalante Chacocente wildlife reserve on Nicaragua’s Pacific coast to lay their eggs. Though leatherback nesting habits vary, Chacocente has been a reliable egg-laying site for as long as conservationists have collected nesting data. But this year, not a single leatherback came to Chacocente, and conservation groups in Costa Rica and Mexico, have recorded declines in sightings of the huge turtles. Leatherback populations face threats from human activity, and the eastern Pacific population of leatherbacks is classified as critically endangered. Both legal and illegal fishing have helped drive the decline, as well as egg poaching. In Central America sea turtle eggs are considered a delicacy and in some communities are held to be an aphrodisiac. While conservation efforts have focused on countering human harvesting of turtles, there is also growing evidence that warming temperatures could play a role in the population decline. In leatherbacks and other species of sea turtles, the sex of a turtle hatchling is determined by the temperature of the sand where the egg incubated. Higher temperatures produce female eggs, and scientists suspect that a large portion of sea turtle hatchlings are now...
Climate Change Threat to Dolphins’ Survival

Climate Change Threat to Dolphins’ Survival

SOURCE: University of Zurich DATE: April 1, 2019 SNIP: An unprecedented marine heatwave had long-lasting negative impacts on both survival and birth rates on the iconic dolphin population in Shark Bay, Western Australia. Researchers at UZH have now documented that climate change may have more far-reaching consequences for the conservation of marine mammals than previously thought. Shark Bay in Western Australia in early 2011: A heatwave causes the water temperatures to rise to more than four degrees above the annual average. The extended period caused a substantial loss of seagrass, which drives the Shark Bay ecosystem, in this coastal area, a UNESCO world heritage site. Researchers from UZH have now investigated how this environmental damage has affected survival and reproduction of dolphins. They used long-term data on hundreds of animals collected over a ten-year period from 2007 to 2017. Their analyses revealed that the dolphins’ survival rate had fallen by 12 percent following the heatwave of 2011. Moreover, female dolphins were giving birth to fewer calves – a phenomenon that lasted at least until 2017. “The extent of the negative influence of the heatwave surprised us,” says Sonja Wild, former PhD candidate at the University of Leeds and first author of the study. “It is particularly unusual that the reproductive success of females appears to have not returned to normal levels, even after six...