Earth Sciences, PHYS.ORG
A reduction in the amount of oxygen dissolved in the oceans due to climate change is already discernible in some parts of the world and should be evident across large regions of the oceans between 2030 and 2040, according to a new study led by the National Center for Atmospheric Research (NCAR).
Scientists know that a warming climate can be expected to gradually sap oceans of oxygen, leaving fish, crabs, squid, sea stars, and other marine life struggling to breathe. But it’s been difficult to determine whether this anticipated oxygen drain is already having a noticeable impact.
“Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” said NCAR scientist Matthew Long, lead author of the study. “Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it’s been challenging to attribute any deoxygenation to climate change. This new study tells us when we can expect the impact from climate change to overwhelm the natural variability.”
The study is published in the journal Global Biogeochemical Cycles, a publication of the American Geophysical Union. The research was funded by the National Science Foundation, NCAR’s sponsor.
Read more at: Widespread loss of ocean oxygen to become noticeable in 2030s
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
Henry Fountain, THE NEW YORK TIMES
Less than a year after one of the strongest El Niños on record, forecasters see an increasing possibility that another will begin later this year.
There is no word yet on how strong a new El Niño might be, but even a mild one could affect weather patterns around the world. Among the potential effects are wetter conditions across the southern United States, including Southern California; a drier Midwest; and drought in parts of Africa, Asia and South America.
An El Niño can also influence global temperatures that are already rising because of greenhouse gas emissions. The strong El Niño of 2015-16 contributed to those years’ being the two warmest on record.
An El Niño occurs when warm water in the equatorial Pacific shifts, creating an immense warm zone in the central and eastern Pacific. This adds heat and moisture to the air, releasing energy that affects the high-altitude winds known as jet streams that circle the planet.
A small bunch of tiny red crustaceans that ought to be hanging out a thousand miles south of here came ashore on Salmon Creek Beach last week, the final remnants, it seems, of a wave of southern species brought north by unusually warm ocean conditions over the past few years.
The 18 pelagic red crabs now living at the UC Davis Bodega Marine Lab are the first ones reported this far north since 1985, when an isolated sighting was recorded in Fort Bragg, according to Eric Sanford, a UC Davis professor of evolution and ecology.
But those who follow life along the Pacific Coast may recall seeing images of the spidery, vermilion-colored creatures as they came ashore by the thousands last year in Monterey and a year prior, when beaches on both the Central Coast and in and around Orange County were covered in blankets of bright red crabs.
At the time, ocean waters were atypically high, a result initially of a phenomenon called “The Warm Blob” and then an ensuing El Niño ocean warming phase of record strength.
The surprise in finding the rare crabs off the Sonoma Coast at this point in time is that the ocean waters have cooled significantly over the past nine months or so, when the latest El Niño dissipated, Sanford said.
“They’re more often found in southern and central Baja, off of Mexico, and it’s very rare to see them even in the state of California,” Sanford said.
Seeing them now “is just another indicator of how strong that El Niño was,” he said.
Mass-starvation events have hit a spectrum of other West Coast marine wildlife, mostly due to the collapse of food chains brought on by warmer ocean water.
In any other year, the large bins of Dungeness crab that are loaded dockside in this busy fishing village and rolled out by truck to be sold and served during the holidays would seem like no big deal.
But after an unprecedented delay in the 2015-16 commercial season forced local crabbers to leave their boats tied up through winter and on into spring, the tons of meaty crustaceans landed in port this month have been a welcome sign of normalcy restored, if only for a moment.
For here on the edge of the Pacific, where commercial fishing remains a way of life, once reliable ocean rhythms have been seriously unsettled of late, confounding those who depend on predictable, seasonal cycles and highlighting future uncertainties.
Even the current Dungeness season lurched off to a bumpy start, with the fishery opening piecemeal and mostly behind schedule, a symptom of widespread marine anomalies that have prevailed for the past three years, threatening everything from seabirds and sea lions to treasured catches such as salmon and abalone.
“The ocean is changing,” one glum crabber aboard the vessel New Horizon said while waiting to unload his catch recently at Tides Wharf. Offshore a strong storm was building and the fisherman summed up the fishing industry’s environmental troubles with hard-earned experience.
“Irregularity “is starting to look like the new normal,” he said.
Scientists and fishermen alike are unsure about the degree to which recent upheaval fits within the ocean’s normal rhythms — which are complex — or is part of some longer-term trend, perhaps linked to global climate change and its many ripple effects.
It’s likely a bit of both, given the context of the Earth’s warming, though more immediate atmospheric conditions have been the primary suspect, scientists say.
“Climate change syndrome is definitely having an impact,” said John Largier, professor of coastal oceanography at the UC Davis Bodega Marine Laboratory. “…What is very difficult to tell is how much.”
It appears that an expanse of high-temperature water along the coast of North American known as “the Warm Blob” is mostly to blame for recent disturbances affecting the coast of California, causing significant redistribution of wildlife, disruptions in the food web and large-scale mortality in a variety of animals.
Read more at: Year in Review: Ocean changes upend North Coast fisheries | The Press Democrat
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
How to help: State scientists are seeking help with data collection and other activities, as well as observational accounts, photos and videos related to the urchin barren. Shared images and information should, if possible, include the date, location and depth at which they were acquired. Contact Cynthia Catton at Cynthia.Catton@wildlife.ca.gov or 875-2072.
Large tracts of kelp forest that once blanketed the sea off the North Coast have vanished over the past two years, a startling transformation that scientists say stems from rapid ecological change and has potentially far-reaching impacts, including on several valuable fisheries.
The unprecedented collapse has been observed along hundreds of miles of coastline from San Francisco to Oregon. The region’s once-lush stands of bull kelp, a large brown alga that provides food and habitat for a host of wildlife species, have been devoured by small, voracious purple urchins. In the most-affected areas, denuded kelp stalks are almost all that remains of plant life.
Scientists have described the landscape left behind as an “urchin barren.” Other factors, including warmer water, also are to blame, they say.
“It’s no longer a kelp forest,” said Cynthia Catton, an environmental scientist with the California Department of Fish and Wildlife, stationed in Bodega Bay.Laura Rogers-Bennett, another Bodega Bay scientist, said it is as if whole terrestrial forests were disappearing, only in this case they are underwater and out of sight.
“A lot fewer people swim through the kelp forest,” she said. “But if they do right now, they‘re going to really see that there are huge changes that have taken place in the last year and a half or so.
”The discovery has taken shape as California scientists and policy makers are raising a broader alarm over the ebbing health of ocean waters, pointing to their increasing warmth, acidity and other conditions that have affected wildlife and the fishing industry.
Read more at: Collapse of kelp forest imperils North Coast ocean ecosystem | The Press Democrat
Mary Callahan, THE PRESS DEMOCRAT
With the wait underway for federal aid that might help idled fishermen amid the unprecedented closure of California’s commercial Dungeness crab season, scientists and lawmakers assembled at the state capitol Thursday to grapple with other looming hardships ahead for those who make their living on the seas.
Between drought, the increasing warmth and acidity of ocean waters and other factors that have disrupted conditions and wildlife habitat, the outlook is overwhelmingly grim, presenters said at an annual forum of the joint legislative Committee on Fisheries and Aquaculture.
“Something’s going on in the ocean, and it’s not right, and it doesn’t fit our historical understandings,” California Fish and Wildlife Director Chuck Bonham told members of the committee, led by state Sen. Mike McGuire, D-Healdsburg.Bonham noted stretches of coastline suddenly barren of sea urchins, while tropical sea snakes and other warm water species are plying the waters off the California coast. The prolonged algal bloom and resulting neurotoxin that has shut down the state’s commercial crab season is among numerous anomalies that are growing increasingly apparent, Bonham said.
“This should be an … alarm to the general public to stay aware and engaged in this ecological change that’s going on in the ocean,” Bonham said.
Commercial fishermen, especially those on the North Coast, are all too aware of the impacts, having come off a dismal salmon season last summer. The second blow was the postponement of the crab season over human health concerns presented by a naturally occurring neurotoxin called domoic acid that has persisted in a massive algae bloom off the West Coast.
What’s worse, said Clarissa Anderson, an assistant researcher at UC Santa Cruz’s Institute of Marine Sciences, is the record levels of domoic acid follow an overall rise in the neurotoxin since a shift in conditions observed in 1998.
“There have been a few dips in there, but in the last five, six years, we start to see an unprecedented level every year,” Anderson said.
Read more at: Scientists and lawmakers foresee grim outlook for California’s | The Press Democrat
The northern fur seal strandings are the latest in a string of alarming marine events. Experts have been working all year to address an “unusual mortality event” among California sea lions.
Another species of marine wildlife has begun turning up, emaciated and weak, in record numbers on the California coast in what continue to be alarming signs of oceanic distress.
Unhealthy northern fur seal pups have been found stranded on beaches in record numbers, newly weaned and weighing little more than typical birth weight for the species, marine mammal experts said.
“They’re adorable, but on the other hand they’re these little bags of skin and bones,” said Jeff Boehm, executive director of the Marine Mammal Center near Sausalito.
As of Friday, the nonprofit center on the Marin Headlands had taken in 85 northern fur seals, which live out in the Pacific Ocean’s waters and islands and would only rarely be found on shore.
That number is more than double the previous record of 31 pups in 2006, according to the center.
Read more at: Sausalito’s Marine Mammal Center sees record number of | The Press Democrat
Rong-Gong Lin II & Rosanna Xia, LOS ANGELES TIMES
A key location of the Pacific Ocean is now hotter than recorded in at least 25 years, surpassing the temperatures during the record 1997 El Niño.
Some scientists say their measurements show that this year’s El Niño could be among the most powerful on record — and even topple the 1997 event from its pedestal.
“This thing is still growing and it’s definitely warmer than it was in 1997,” said Bill Patzert, climatologist with NASA’s Jet Propulsion Laboratory in La Cañada Flintridge. As far as the temperature readings go, “it’s now bypassed the previous champ of the modern satellite era — the 1997 El Niño has just been toppled by 2015.”
Daniel Swain, a climate scientist at Stanford University, called the temperature reading significant. It is the highest such weekly temperature above the average in 25 years of modern record keeping in this key region of the Pacific Ocean west of Peru.
“This is a very impressive number,” Swain said, adding that data suggest that this El Niño is still warming up. “It does look like it’s possible that there’s still additional warming” to come.“
We’re definitely in the top tier of El Niño events,” Swain said.
Temperatures in this key area of the Pacific Ocean rose to 5.4 degrees Fahrenheit above average for the week of Nov. 11. That exceeds the highest comparable reading for the most powerful El Niño on record, when temperatures rose 5 degrees Fahrenheit above the average the week of Thanksgiving in 1997.
Read more at: El Niño could be the most powerful on record, scientists say – LA Times