Darryl Fears, WASHINGTON POST
Six years after it was stricken by a wasting disease off the northern California coast, the sunflower sea star – one of the most colorful starfish in the ocean – has all but vanished, and the domino effect threatens to unravel an entire marine ecosystem.
The cause of the sea star’s demise is a mystery, but it coincided with a warming event in the Pacific Ocean, possibly tied to the climate, that lasted for two years ending in 2015. It heated vast stretches of water in patches, and likely exacerbated the disease, according to a new study released Wednesday.
“I’ve never seen a decline of this magnitude of a species so important,” Drew Harvell, the lead author of the study, published in the journal Science Advances, that documented the sunflower sea star’s retreat into possible extinction off California and Oregon.
If the study had a purpose, she said, it was to call attention to the sea star’s demise so that federal officials would take action to list it as endangered and work to save it, possibly with a breeding program using sunflower stars that are surviving in parts of Washington, Alaska and Canada.
“It’s big news and cause for major management action,” Harvell said. “We felt there wasn’t enough attention.”
Read more at https://www.adn.com/nation-world/2019/02/01/colorful-sea-star-stricken-by-disease-vanishes-from-most-of-the-west-coast/
Mary Callahan, THE PRESS DEMOCRAT
Aerial surveys conducted each year to gauge abundance in the iconic kelp forests off the North Coast showed a slight improvement last fall, offering a glimmer of hope for the recovery of the coastal marine habitat, the California Department of Fish and Wildlife has reported.
But conditions for the “bull kelp,” an annual type of seaweed — especially off Sonoma County — have become so bleak in recent years that even a reported doubling of the forest canopy during last year’s growing season has done little to bring the underwater habitat back to full strength, scientists said.
Despite patches that resemble the historic ecosystem in some ways, large swaths of ocean floor off the North Coast remain devoid of bull kelp and other fleshy algal species, prompting continued starvation among common marine herbivores like red abalone and urchins, they said.
Even with growth in the overall canopy last year, data indicates the kelp off Sonoma and Mendocino counties covered at least 95 percent less surface area in 2016 than it did in the banner year of 2008, said Cynthia Catton, an environmental scientist with the state wildlife agency.
The apparent expansion of the kelp canopy “is deceptive,” said Sonke Mastrup, environmental program manager for the agency’s invertebrate program, “because 2016 is still way below anything we would consider normal.”
Read more at: Along the North Coast, mixed news about the health of the undersea kelp forest | The Press Democrat
Mary Callahan, THE PRESS DEMOCRAT
Scientists at the UC Davis Bodega Marine Laboratory say a new study shows that the response by certain aquatic animals to warming ocean temperatures may make them more vulnerable to growing acidification, a secondary effect of climate change already measurable off the Sonoma Coast.
The research showed that organisms called bryozoan changed the composition of their skeletons in warm water to ones that quickly dissolved when exposed to water of higher acidity, causing the animals to shut down, lead author Dan Swezey said. He said the study mimicked condititions expected to be widespread by the end of the century.
The findings suggest that some marine life faced with adapting to a shifting ocean environment may be in a double bind when confronted with the “one-two punch” of global warming, a university representative said, with implications for sea stars, sea urchins, coralline algae and other ecologically significant marine life that depend on mineralized skeletons containing magnesium.
UC Davis spokeswoman Kat Kerlin likened the bryozoan to a “canary in a coal mine.”
“Our results add to this growing body of evidence that ocean acidification is a threat for lots of marine animals that are producing hard shells and skeletons,” said the study’s co-author, Eric Sanford, a professor of evolution and ecology. “But that might be increasingly true if the trend of acidification is combined with this trend of warming oceans.”
Read more at: UC Davis study: North Coast water changes affecting marine life | The Press Democrat