Tag Archives: ocean warming

Op-Ed: It’s a fact: climate change made Hurricane Harvey more deadly 

Michael Mann, THE GUARDIAN

What can we say about the role of climate change in the unprecedented disaster that is unfolding in Houston with Hurricane Harvey? There are certain climate change-related factors that we can, with great confidence, say worsened the flooding. What we know so far about tropical storm Harvey Read more Sea level rise attributable to climate change – some of which is due to coastal subsidence caused by human disturbance such as oil drilling – is more than half a foot (15cm) over the past few decades (see here for a decent discussion). That means the storm surge was half a foot higher than it would have been just decades ago, meaning far more flooding and destruction.

In addition to that, sea surface temperatures in the region have risen about 0.5C (close to 1F) over the past few decades from roughly 30C (86F) to 30.5C (87F), which contributed to the very warm sea surface temperatures (30.5-31C, or 87-88F).

There is a simple thermodynamic relationship known as the Clausius-Clapeyron equation that tells us there is a roughly 3% increase in average atmospheric moisture content for each 0.5C of warming. Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average temperatures, which translates to 1-1.5C warmer than “average” temperatures a few decades ago. That means 3-5% more moisture in the atmosphere.

That large amount of moisture creates the potential for much greater rainfalls and greater flooding. The combination of coastal flooding and heavy rainfall is responsible for the devastating flooding that Houston is experiencing.

Not only are the surface waters of the Gulf of Mexico unusually warm right now, but there is a deep layer of warm water that Harvey was able to feed upon when it intensified at near record pace as it neared the coast. Human-caused warming is penetrating down into the ocean. It’s creating deeper layers of warm water in the Gulf and elsewhere.

Read more at: It’s a fact: climate change made Hurricane Harvey more deadly | Michael E Mann | Opinion | The Guardian

Filed under Climate Change & Energy

More limits foreseen for California abalone fishery as scientist raises alarm 

Mary Callahan, THE PRESS DEMOCRAT

The crisis comes in the wake of a massive deterioration in the spread and health of North Coast kelp forest over the past several years, a consequence of what scientists call “a perfect storm” of large-scale stressors that include two years of unprecedented and prolonged warm ocean conditions.

A marine wildlife expert put California fish and game commissioners on notice Thursday that significant new restrictions in the abalone fishery — including more closures — may be necessary next year because of continued starvation and die-off among the sought-after mollusks.

Even a shutdown of the iconic North Coast sport fishery should be on the table, though only as a worst-case scenario, said Sonke Mastrup, invertebrate program manager for the California Department of Fish and Wildlife.

“What we’re seeing is going to have long-term implications,” Mastrup said in an interview. “This is not a temporary problem, and what that turns into, we don’t know yet, and it’s appropriate to start having the conversation so people aren’t shocked down the road.”

No decisions regarding the 2018 season need to be made until later this year, after the results of annual underwater surveys conducted in August and September are available, Mastrup told the California Fish and Game Commission at its regular, bi-monthly meeting, held in Smith River.

But commissioners and the public need to be prepared for the possibility of drastic measures, given declining health and reproductive capacity among red abalone on the North Coast, he told commissioners.

Read more at: More limits foreseen for California abalone fishery as scientist raises alarm | The Press Democrat

Filed under Sonoma Coast, Wildlife

Widespread loss of ocean oxygen to become noticeable in 2030s

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 . 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

Filed under Climate Change & Energy, Wildlife

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

Filed under Climate Change & Energy, Sonoma Coast, Wildlife

It’s like it never left: Another El Niño may be on the way

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.

Read more at: It’s Like It Never Left: Another El Niño May Be on the Way – The New York Times

Filed under Climate Change & Energy

Red crabs deposited on Sonoma Coast by unusual ocean conditions

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.

Read more at: Red crabs deposited on Sonoma Coast by unusual ocean conditions

Filed under Sonoma Coast, Wildlife

Ocean rhythms are changing, ocean wildlife dying

Mary Callahan, THE PRESS DEMOCRAT

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

Filed under Climate Change & Energy, Sonoma Coast, Wildlife

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

Filed under Climate Change & Energy

Collapse of kelp forest imperils North Coast ocean ecosystem

Mary Callahan, THE PRESS DEMOCRAT

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

Filed under Habitats, Sonoma Coast, Wildlife

Outlook grim for oceanic habitats

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

Filed under Agriculture/Food System, Sonoma Coast, Wildlife