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
Weston Williams, THE CHRISTIAN SCIENCE MONITOR
The annual low for atmospheric concentrations of carbon dioxide has crossed the 400 parts per million threshold, a level not seen for millions of years.
Earth may have passed a significant symbolic threshold as the global climate continues to grow warmer.Usually, September marks a low in the amount of carbon dioxide (CO2) in the atmosphere. This concentration sets the bar over which levels of the greenhouse gas will fluctuate throughout the next year. But this September, CO2 levels are staying high, at around 400 parts per million, and many scientists think that we will not see levels of the greenhouse gas drop below that threshold within our lifetimes.
Earth has been steadily building up CO2 in the atmosphere since the Industrial Revolution, but the 400 ppm landmark is creating a new normal that hasn’t been seen on this planet for millions of years.
“The last time our planet saw 400 ppm carbon dioxide in our atmosphere was about 3.5 million years ago, and global climate was distinctly different than today,” David Black, associate professor in the School of Marine and Atmospheric Sciences at Stony Brook University in New York, tells The Christian Science Monitor in an email.
Read more at: Earth CO2 levels: Have we crossed a point of no return? – CSMonitor.com
A world-first global analysis of marine responses to climbing human carbon dioxide emissions has painted a grim picture of future fisheries and ocean ecosystems.
University of Adelaide, Australia
Published October 12 in the journal Proceedings of the National Academy of Sciences (PNAS), marine ecologists from the University of Adelaide say the expected ocean acidification and warming is likely to produce a reduction in diversity and numbers of various key species that underpin marine ecosystems around the world.
“This ‘simplification’ of our oceans will have profound consequences for our current way of life, particularly for coastal populations and those that rely on oceans for food and trade,” says Associate Professor Ivan Nagelkerken, Australian Research Council (ARC) Future Fellow with the University’s Environment Institute.
Associate Professor Nagelkerken and fellow University of Adelaide marine ecologist Professor Sean Connell have conducted a ‘meta-analysis’ of the data from 632 published experiments covering tropical to artic waters, and a range of ecosystems from coral reefs, through kelp forests to open oceans.
“We know relatively little about how climate change will affect the marine environment,” says Professor Connell. “Until now, there has been almost total reliance on qualitative reviews and perspectives of potential global change. Where quantitative assessments exist, they typically focus on single stressors, single ecosystems or single species.
“This analysis combines the results of all these experiments to study the combined effects of multiple stressors on whole communities, including species interactions and different measures of responses to climate change.”
The researchers found that there would be “limited scope” for acclimation to warmer waters and acidification. Very few species will escape the negative effects of increasing CO2, with an expected large reduction in species diversity and abundance across the globe. One exception will be microorganisms, which are expected to increase in number and diversity.
From a total food web point of view, primary production from the smallest plankton is expected to increase in the warmer waters but this often doesn’t translate into secondary production (the zooplankton and smaller fish) which shows decreased productivity under ocean acidification.
“With higher metabolic rates in the warmer water, and therefore a greater demand for food, there is a mismatch with less food available for carnivores ─ the bigger fish that fisheries industries are based around,” says Associate Professor Nagelkerken. “There will be a species collapse from the top of the food chain down.”
The analysis also showed that with warmer waters or increased acidification or both, there would be deleterious impacts on habitat-forming species for example coral, oysters and mussels. Any slight change in the health of habitats would have a broad impact on a wide range of species these reefs harbour.
Another finding was that acidification would lead to a decline in dimethylsulfide gas (DMS) production by ocean plankton which helps cloud formation and therefore in controlling Earth’s heat exchange.
Source: Global marine analysis suggests food chain collapse — ScienceDaily
Mary Callahan, THE PRESS DEMOCRAT
Experts meet to develop strategy to combat carbon dioxide-related changes affecting sea creatures
SAN JOSE — Members of a multidisciplinary panel tackling the related problems of ocean acidification and low-oxygen zones off the western shore of the continent conceded Sunday they had little to offer yet in the way of solutions beyond what most of us know: We need to dump less carbon dioxide into the air.
But scientists associated with the West Coast Ocean Acidification and Hypoxia Science Panel offered hope in a uniquely collaborative, cross-jurisdictional approach set up to move quickly toward a more complete understanding of shifting ocean conditions that enables direct feedback to government decision-makers who can compel action.
The 20-member panel includes representatives from varied research areas across California, Oregon, Washington and British Columbia, but also has the support of governors of those regions and an urgent desire to develop action strategies, members said during a session of the American Association for the Advancement of Science’s annual convention in San Jose.
The idea is to accelerate the already growing body of research on changing ocean chemistry and tailor studies specifically so government regulators, industry and scientific innovators can adapt problem-solving techniques.
“We want to make sure we have the answers while they’re still useful,” said Francis Chan, an assistant professor in the department of integrative biology at Oregon State University.
Read more via Effort afoot to ramp up study of West | The Press Democrat.
KQED Forum program on ocean acidification.
Mary Callahan, THE PRESS DEMOCRAT
It’s been called the “evil twin” of climate change, an environmental peril so daunting and widespread that it could undo much of the world’s food web, undermine global nutrition and devastate coastal economies.
Ocean acidification, however, is often largely overlooked outside the circles of scientists, yet North Coast Congressman Jared Huffman is seeking to somehow change that and spur action on the issue before it’s too late.
Acidification of the world’s oceans, said Huffman, D-San Rafael, “is the biggest thing that nobody is talking about.”
Shellfish grown off the nation’s West Coast already display the ill effects of rapid changes in the ocean’s chemistry, an early sign that the health of the marine ecosystem could hang in the balance, Huffman said.
“You can’t really overstate the impact of this,” Huffman said at a news conference this week at Bodega Marine Laboratory that was attended by representatives from science, aquaculture and government.
“We’re very, very quickly approaching the tipping point, I believe,” Huffman said.
via Concern about ocean acidity prompting new attention | The Press Democrat.
Paul Rogers, SAN JOSE MERCURY NEWS
In a troubling new discovery, scientists studying ocean waters off California, Oregon and Washington have found the first evidence that increasing acidity in the ocean is dissolving the shells of a key species of tiny sea creature at the base of the food chain.
The animals, a type of free-floating marine snail known as pteropods, are an important food source for salmon, herring, mackerel and other fish in the Pacific Ocean. Those fish are eaten not only by millions of people every year, but also by a wide variety of other sea creatures, from whales to dolphins to sea lions.
If the trend continues, climate change scientists say, it will imperil the ocean environment.
"These are alarm bells," said Nina Bednarsek, a scientist with the National Oceanic and Atmospheric Administration in Seattle who helped lead the research. "This study makes us understand that we have made an impact on the ocean environment to the extent where we can actually see the shells dissolving right now."
Scientists from NOAA and Oregon State University found that in waters near the West Coast shoreline, 53 percent of the tiny floating snails had shells that were severely dissolving — double the estimate from 200 years ago.
via Climate change: Pacific Ocean acidity dissolving shells of key species – San Jose Mercury News.
Guy Kovner, THE PRESS DEMOCRAT
With consumers wolfing down millions of its shellfish every year and clamoring for more, Hog Island Oyster Co. should be sitting pretty on the east shore of scenic Tomales Bay, a bountiful estuary abutting Point Reyes National Seashore.
Co-founder John Finger, a surfer-entrepreneur with a degree in marine biology, decided to farm the mile-wide and 15-mile-long bay due to its productivity and proximity to the Bay Area’s food-savvy multitudes.
Seeded by a $500 family loan in 1983, the oyster farm has prospered — propelled by a nationwide yen for raw oysters on the half shell — into a business that sells about $10 million worth of bivalves a year, employing about 120 workers who feel a bit like family themselves.
via Ground zero for future of oyster farming | The Press Democrat.