In 1799 about a hundred Aleut hunters working for a Russian-American trading group died in Alaska’s Peril Strait only two hours after eating black mussels collected there. Those who survived did so because they threw up after desperately consuming gunpowder, tobacco and alcohol to purge toxin from their bodies. This was the first recorded incidence of paralytic shellfish poisoning on the west coast of North America.

The Aleuts were killed by natural poisons known as toxins produced by certain algae that were trapped in the mussels’ food-gathering filters. Filter feeders like shellfish, some finned fish and other animals concentrate the toxins present in these algae.

Physical and chemical conditions cause populations of algae to wax and wane in cycles. Out of the vast diversity of plankton in the oceans, the worst offenders are a few species of diatoms, dinoflagellates and cyanobacteria, collectively called harmful algae. For example, some diatoms make domoic acid, which causes vomiting, cramping, headache and even seizures and memory loss; some dinoflagellates produce saxitoxin, which causes numbness, staggering and respiratory failure, among other symptoms.

Toxic blooms can occur naturally when deep, nutrient-rich water wells up in places like the west coasts of North and South America. They can be amplified by land runoff of fertilizers and other chemicals that provide nutrients such as phosphorus. Algal blooms have been increasing in coastal waters nearly everywhere.

In mid-December 2012 recreational mussel harvesting was closed along the entire Oregon coast because the mussels were contaminated with paralytic shellfish toxins. In 2002 razor clam harvesting was prohibited for the full season in Washington State because of high domoic acid levels. Florida’s coastline has frequent outbreaks of the toxic dinoflagellate Karenia brevis, whose toxins can escape into the air and cause severe respiratory distress. Today in the U.S. alone such incidents cause $82 million in public health costs and economic damages to fisheries and tourism annually, according to the National Oceanic and Atmospheric Administration (NOAA). These costs include emergency room visits and other medical treatment, lost work productivity, and fewer dollars reaching local businesses if beaches and sport or commercial fishing is curtailed.

Now scientists are investigating whether climate change could contribute to toxic blooms. As atmospheric carbon dioxide increases, the greenhouse gas is absorbed into ocean water, making it more acidic. The most obvious peril is that marine organisms like clams and sea snails either can’t build their calcium carbonate shells or find their housing harder to maintain. Acidifying ocean conditions could cause toxic algae to become nastier and more abundant. Conversely, the organisms might simply adapt without becoming more poisonous; their numbers could even be reduced.

Of course, researchers must assess ocean acidification as one of many simultaneous stressors in the oceanic environment. Scientists don’t fully understand the relationship between growth rates, toxin production and ocean conditions for these algae. Some species are known to ramp-up toxin production as a defense against predators, others in response to low supplies of crucial nutrients. Another possibility is that the toxins are simply a way for a diatom or dinoflagellate to store excess nutrients, such as carbon or nitrogen, rather than a stress response, says microbial ecologist William Cochlan of San Francisco State University.

To see how nutrient limitation and acidification interact, Avery Tatters, a graduate student in David Hutchins’s lab at the University of Southern California, cultured the diatom Pseudo-nitzschia fraudulenta taken from southern California waters, where it blooms frequently. The species produces domoic acid.

7 Comments

1. 1. dkahn400 in reply to Shoshin 10:53 AM 12/21/12

   Shoshin. The article is about ocean acidification, not global warming. You could at least bother to read the article before spreading your knee-jerk disinformation. The article is also about toxicity so it at least has that in common with your post.

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2. 2. Fossilnut 11:20 AM 12/21/12

   Shshin:
   
   "More Alarmist garbage...."
   
   Agreed. A Global warming groupies' agenda overlaid on what should be science artcle devoid of speculative buzz words.

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3. 3. bsebadger in reply to Shoshin 12:57 PM 12/21/12

   Gee, what tipped you off? The title?
   
   As dkahn400 responded, this article does not try to reinforce the rather well-substantiated phenomenon of anthropogenic climate change as you vociferously insisted. No sir, it actually talks about how increased use of fertilizers influence algal blooms (eutrophication) and how several factors (increased levels of CO2, rise in temperatures, and any others) affected the growth of these organisms and the composition of the toxins they produce... which you would have realized, had you bothered to read more than just the title and pounced onto your guns yelling murder.
   
   Of course, as you state, you would rather prefer articles that are really political in nature, but are thinly veiled as science stories. As you put it, these would be '...infinitely more enlightening and relevant.' If that is how most self-ascribed climate change skeptics feel, then it is a very sad state of affairs. To eagerly expect sensational and seemingly-vindictive rumor-mill stories that scream of non-existent conspiracies is doing a disservice to the erstwhile noble epithet of a 'skeptic'.
   
   I sincerely hope you get a chance to enjoy science without trying to politically deconstruct it just to promote a specific idealistic agenda that may or may not conform with the scientific evidence.

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4. 4. Nickuru 08:42 PM 12/21/12

   The perchlorate ion is stable kinetically. Meaning the perchlorate ion has a very high activation energy barrier. This is because it exists in the square planar configuration, labelled D4h in the Schoenflies geometric system. It has an immense amount of chemical energy, and once the D4h symmetry is broken it becomes extremely reactive. Putting perchlorate in contact with fuels like oil, graphite and sulphur is not harmful. However if you activate the mixture you had best be far away.

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5. 5. rodestar99 in reply to dkahn400 07:52 AM 12/22/12

   Dkhan400
   Regardless of what it is about. It is full of could
   be's, might bees, maybes, "needs more studies" , give
   me money for more researches" etc. They are starting
   out with a premise and then looking for ways to prove it.
   This is the way that Pseudo science is conducted
   these days. And this is the way that every weather
   phenomenon or any other natural phenomenon gets attributed to mans activities.
   This is kind of like the approach that prosecuting attorneys use in getting a conviction. Just keep throwing stuff at the wall until you get something that sticks. Make a case ...no matter how shaky and then make people disprove it. This is not science ...this is an agenda.
   Man is part of the environment and we can effect it
   just like animals can over graze their pastures.
   Wringing our hands over it is not going to change it
   and no matter what measures we take for conservation they are all bound to fail as long as we keep increasing
   our numbers . The ONLY long term solution is to control
   our numbers and this is where we need to be focusing
   our efforts. Anything else is doomed to failure.
   

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6. 6. Postman1 11:05 PM 12/25/12

   “The work is really at an early stage,” says Ulf Riebesell, a professor of biological oceanography at the Helmholtz Center for Ocean Research in Kiel, Germany. But it is fair to say that as algae and other tiny ocean species solve new survival problems, they may force us to do the same.
   
   This last paragraph says it all and makes one wonder what the point is in printing this, unless it is part of an agenda, or begging for more research dollars.

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7. 7. IslandGardener in reply to rodestar99 04:08 AM 1/1/13

   rodestar99 - You say 'The ONLY long term solution is to control our numbers and this is where we need to be focusing our efforts. Anything else is doomed to failure.'
   
   I agree with you that we the human species do need to reduce our numbers. But that is most definitely not the only thing we need to do, even if all other efforts will be 'doomed to failure' if we don't also reduce our population.
   
   But when you say the article 'is full of could
   be's, might bees, maybes, "needs more studies" , give
   me money for more researches" etc. They are starting
   out with a premise and then looking for ways to prove it' I'm not sure why you're surprised.
   You say 'This is the way that Pseudo science is conducted these days.'
   But what scientists - real scientists - do is precisely to start with a premise and then go and look for evidence to prove or disprove it.
   As for 'And this is the way that every weather phenomenon or any other natural phenomenon gets attributed to mans activities' I don't know that any climate scientists claim that human beings are responsible for everything! Climate scientists have made huge efforts in research and in modelling to find out what contribution human activities make, and what contribution natural forces make, to the climate. Unless we understand both we can't understand the world.
   
   Back to my first point. As bsebadger says, the article also mentions the now well-known phenomenon that fertiliser runoff makes algal blooms worse. So as well as reducing our population we need to grow our food in more sustainable ways.
   
   Examples include growing nitrogen-fixing plants such as legumes to reduce fertiliser use, increasing soil aeration and organic matter to enable soils to absorb water and nutrients, switching from annual crops to perennial crops and from simplistic monocultures to polycultures so that more extensive, diverse and effective root systems can absorb nutrients better, and increasing woods, orchards, scrub and hedges to absorb runoff.
   
   See for example http://en.wikipedia.org/wiki/Agroforestry.
   

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