Posts Tagged ‘Ocean acidification’

Global ocean warming – never mind being washed away, it can kill you if you eat crabs.

Posted: November 5, 2015 in Political musings, Science
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Potentially deadly.

Potentially deadly.

Dungeness and rock crabs in California have been found to contain toxic levels of an acid that can kill.

The authorities in California are advising people to avoid consumption of crabs contaminated by a natural toxin that has spread throughout the marine ecosystem off the West Coast, killing sea mammals and poisoning various other species.

Kathi A. Lefebvre, the lead research biologist at the Wildlife Algal Toxin Research and Response Network, said on Wednesday that her organization had examined about 250 animals stranded on the West Coast and had found domoic acid, a toxic chemical produced by a species of algae, in 36 animals of several species.

“We’re seeing much higher contamination in the marine food web this year in this huge geographic expanse than in the past,” Ms. Lefebvre said.

She said that the toxin had never before been found in animals stranded in Washington or Oregon, and that there were most likely greater numbers of contaminated marine mammals not being found by humans.

The guilty algae’s growth has been exponential recently, largely because of record temperatures in the Pacific Ocean. Warm water causes the toxic algae to divide more rapidly and to outcompete other species in the water. The algae then becomes a more prominent element of local plankton, a kind of marine trail mix made up of tiny particles that various species of aquatic wildlife subsist on.

The California Department of Public Health recently advised people to avoid consumption of certain species of crabs because of potential toxicity. Razor clam fisheries in Washington have been closed throughout the summer for the same reason.

In a statement released on Tuesday, the California department said that “recent test results” indicated dangerous levels of domoic acid in Dungeness and rock crabs caught in California waters between Oregon and Santa Barbara, Calif.

Domoic acid is a naturally occurring toxin that in severe cases can cause excessive bronchial secretions, permanent loss of short-term memory, coma or death in humans, according to the California department’s statement. Milder cases can result in vomiting and diarrhea.

A release from the National Oceanic and Atmospheric Administration Fisheries specified that “commercial seafood remains safe and state public health agencies monitor recreational fisheries for algal toxins.”

Pseudo-nitzschia, the type of algae that produces the acid, is a single-celled organism consumed directly by marine wildlife like anchovies, sardines, krill and razor clams. Those species are then eaten by larger predators, and the acid makes its way up the marine food chain.

This summer, the West Coast experienced the largest algal bloom that scientists have on record. Ms. Lefebvre said that though there was not a lot of monitoring for species that had consumed domoic acid in Alaska, it was likely that the blooms reached the Alaskan coast as well.

Michael Parsons, a professor of marine science at Florida Gulf Coast University, said there were several hypotheses for why Pseudo-nitzschia produces acid.

“We’re not sure exactly why they do it,” he said. “Maybe it’s meant to keep things from eating them. It might be a result of stress.”

If acid secretion is meant to deter predators, it is clear that it is a failing strategy on the part of the algae. Ms. Lefebvre expressed concern that the acid poisoning of sea life would continue to spread.

“My concern is that we’re going to see an increase in the number and geographic range of marine mammals being affected,” she said.

Or in other words, global warming is killing the seas, and now it can kill you too. And that’s before we even return to the topic of ocean acidification and its affect on our food chain. Or how this news will affect commercial fishers, and restaurants.

But don’t worry, everyone, go back to sleep, go back to sleeeeeeep ….

(NY Times and others)

LA Times spells it out: the oceans are dying. Right now.

Posted: January 4, 2013 in Political musings, Popular Culture et al
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As we fiddle about twiddling our intellectual thumbs deciding just how bad global climate change is and what to do about it, time may already have run out for a vital part of the food chain.

Say Goodbye to me.

Say Goodbye to me.

And me.

And me.

And me.

And me.

And me.

And me.

As David Horsey of the LA Times reports, our oceans are not just in danger of becoming murderously acid, it’s happening right now.

He writes:

If the prospect of coastal cities sinking into the sea 100 years from now does not motivate Americans (read, the world) to do something dramatic to reduce carbon dioxide emissions, there is something happening at this very moment that should be setting off sirens. Rising CO2 levels are making the oceans more acidic and that change in the chemistry of the seas is disrupting the food chain that ends with you and me.

For years, as scientists watched the carbon emissions from our tailpipes and smokestacks spew into the sky and goose temperatures higher, there was one mitigating factor that was keeping a brake on global warming: The oceans were absorbing a whole lot of that CO2.

Now, though, it turns out that is not such a blessing. Carbon dioxide welling up from the cold, deep ocean is shifting the pH balance in shallower coastal waters. That rise in acidity is affecting organisms that depend on calcium carbonate to form protective shells and exoskeletons – creatures such as crabs and oysters and clams, as well as coral reefs that provide crucial habitat for many kinds of sea life.

Acidification dissolves shells and coral. There is evidence it also screws up the instinctual guidance systems of at least some types of fish, making them unable to discern the difference between predators and prey. Scientists suspected something bad like this might happen as the oceans grew more sour, but they did not expect it to be happening already.

Researchers are finding that, in several locales, the shells of tiny creatures called pteropods are being thinned and broken down by acidity. People do not eat pteropods, but plenty of fish do. They supply 50% of the diet of pink salmon, and people do eat salmon. It is not hard to understand the biology: If pteropods disappear, salmon and other fish get scarce.

In an interview with the Seattle Times, Gretchen Hofmann, a biologist at UC Santa Barbara stressed how crucial little creatures like pteropods are in maintaining the food chain. “They’re small but carry an enormous amount of nutrition and are eaten even by very big fish. If you’re in the Antarctic and see a beautiful emperor penguin, it exists by eating fish under the sea ice. And those fish eat pteropods.”

Moved to action by a massive die-off of oyster larvae that was traced to acidification, Washington became the first state to establish a blue-ribbon panel to come up with a plan to cope with ocean acidification. The panel released its findings on Tuesday and recommended 42 steps toward adaptation, remediation, monitoring and education.

For now, such efforts may help protect the seafood industry that brings $1.7 billion annually to Washington, but one state cannot fix this problem permanently.

The threat is global. A report by the United Nations Environment Program said, “Fish, including shellfish, contribute 15% of animal protein for three billion people worldwide. A further one billion people rely on fisheries for their primary source of protein. Fish stocks, already declining in many areas due to over-fishing and habitat destruction now face the new threats posed by ocean acidification.”

Each and every day, humans loft 70 million tons of CO2 into the atmosphere, and the seas absorb one quarter of that. Unless we are feeling suicidal, it is time to change our way of doing business. This is not a matter of finding empathy for our grandchildren who will be stuck living on a simmering, stormy planet because we refuse to end our carbon-burning ways, this is a matter of killing off species that feed us today.

Global warming is the foreboding thunder in the distance. Ocean acidification is the lightning strike in our front yard, right here, right now.

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