Tag: ocean acidification

Author SuzannePosted on Categories Agriculture/Food System, Climate Change & Energy, Sonoma Coast, WildlifeTags , , , , ,

Rising ocean acidity bad news for West Coast’s $200 million Dungeness crab fishery

Mary Callahan, THE PRESS DEMOCRAT

Acidification of the world’s oceans was supposed to be a distant problem — nothing to worry about until some time in the future.

But a new study of juvenile Dungeness crab collected off the Pacific Northwest coast shows the crustaceans are vulnerable to conditions that exist right now.

Published last week in the journal “Science of The Total Environment,” the study found that tiny developing crabs sampled from coastal waters off Oregon and Washington suffered damage to their shells as well as to bristly, hairlike sensory organs believed to help them orient to their surroundings.

The findings have unsettling implications for a roughly $200 million West Coast fishery — California’s most valuable ocean crop and a key economic driver for struggling fishing ports on the North and Central Coast.

The California fleet caught more than $47 million worth of Dungeness crab last year, including nearly $5 million worth of crustaceans landed in Bodega Bay.

The new research, said veteran Bodega Bay fishermen Tony Anello, sounds “very discouraging.”

Read more at https://www.pressdemocrat.com/news/10644113-181/rising-ocean-acidity-bad-news

Author SuzannePosted on Categories Climate Change & Energy, Sonoma CoastTags , ,

California coastal waters rising in acidity at alarming rate, study finds

Rosanna Xia, THE LOS ANGELES TIMES

Waters off the California coast are acidifying twice as fast as the global average, scientists found, threatening major fisheries and sounding the alarm that the ocean can absorb only so much more of the world’s carbon emissions.

A new study led by the National Oceanic and Atmospheric Administration also made an unexpected connection between acidification and a climate cycle known as the Pacific Decadal Oscillation — the same shifting forces that other scientists say have a played a big role in the higher and faster rates of sea level rise hitting California in recent years.

El Niño and La Niña cycles, researchers found, also add stress to these extreme changes in the ocean’s chemistry.

These findings come at a time when record amounts of emissions have already exacerbated the stress on the marine environment. When carbon dioxide mixes with seawater, it undergoes chemical reactions that increase the water’s acidity.

Across the globe, coral reefs are dying, oysters and clams are struggling to build their shells, and fish seem to be losing their sense of smell and direction. Harmful algal blooms are getting more toxic — and occurring more frequently. Researchers are barely keeping up with these new issues while still trying to understand what’s happening under the sea.

Read more at https://www.latimes.com/california/story/2019-12-16/ocean-acidification-california

Author SuzannePosted on Categories Climate Change & Energy, Habitats, Sonoma CoastTags , , , , ,

The world’s oceans are in danger, major climate change report warns

Brad Plumer, THE NEW YORK TIMES

Climate change is heating the oceans and altering their chemistry so dramatically that it is threatening seafood supplies, fueling cyclones and floods and posing profound risks to the hundreds of millions of people living along the coasts, according to a sweeping United Nations report issued Wednesday.

The report concludes that the world’s oceans and ice sheets are under such severe stress that the fallout could prove difficult for humans to contain without steep reductions in greenhouse gas emissions. Fish populations are already declining in many regions as warming waters throw marine ecosystems into disarray, according to the report by the Intergovernmental Panel on Climate Change, a group of scientists convened by the United Nations to guide world leaders in policymaking.

“The oceans are sending us so many warning signals that we need to get emissions under control,” said Hans-Otto Pörtner, a marine biologist at the Alfred Wegener Institute in Germany and a lead author of the report. “Ecosystems are changing, food webs are changing, fish stocks are changing, and this turmoil is affecting humans.”

Hotter ocean temperatures, combined with rising sea levels, further imperil coastal regions, the report says, worsening a phenomenon that is already contributing to storms like Hurricane Harvey, which devastated Houston two years ago.
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For decades, the oceans have served as a crucial buffer against global warming, soaking up roughly a quarter of the carbon dioxide that humans emit from power plants, factories and cars, and absorbing more than 90 percent of the excess heat trapped on Earth by carbon dioxide and other greenhouse gases. Without that protection, the land would be heating much more rapidly.

But the oceans themselves are becoming hotter, more acidic and less oxygen-rich as a result, according to the report. If humans keep pumping greenhouse gases into the atmosphere at an increasing rate,marine ecosystems already facing threats from seaborne plastic waste, unsustainable fishing practices and other man-made stresses will be further strained.

Read more at https://www.nytimes.com/2019/09/25/climate/climate-change-oceans-united-nations.html

Author SuzannePosted on Categories Climate Change & Energy, Sonoma Coast, WildlifeTags , , , , ,

UC Davis study: North Coast water changes affecting marine life 

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

Author SuzannePosted on Categories Climate Change & EnergyTags , , , ,

Earth CO2 levels: Have we crossed a point of no return?

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

Author SuzannePosted on Categories Climate Change & Energy, Sonoma Coast, WildlifeTags , , ,

Global marine analysis suggests food chain collapse in oceans

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

Author SuzannePosted on Categories Climate Change & Energy, Sonoma Coast, WildlifeTags , , , Leave a comment on Scientists gather on ocean acidification

Scientists gather on ocean acidification

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.

Author SuzannePosted on Categories Climate Change & Energy, Sonoma CoastTags , Leave a comment on Concern about ocean acidity prompting new attention

Concern about ocean acidity prompting new attention

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.

Author SuzannePosted on Categories Climate Change & Energy, Sonoma Coast, WildlifeTags , Leave a comment on Climate change: Pacific Ocean acidity dissolving shells of key species

Climate change: Pacific Ocean acidity dissolving shells of key species

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.

Author SuzannePosted on Categories Agriculture/Food System, Climate Change & Energy, Sonoma CoastTags , , Leave a comment on Oyster company balances demand, climate change impact

Oyster company balances demand, climate change impact

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.