Extinction of Pteropods

Subtitle: And, eventually you know who, too

Writing for the News and Observer, coral reef and oceanography experts John F. Bruno and Ove Hoegh-Guldberg put the Gulf oil disaster into perspective, then, at Skeptical Science, John Cook took a few excerpts and added some commentary, to which this blog hastened to comment.

First, an excerpt from the article, “In the oceans, the heat is really on”:

The world is saturated by coverage of the oil spill in the Gulf of Mexico. Yet the impacts of this tragedy are localized, short-term and trivial compared to the broader effects of climate change. The oil spill has damaged the lives and businesses of many innocent people. Remarkably, however, every day we are releasing several thousand times as much carbon as the Gulf spill by driving, flying and consuming and by heating and cooling our energy-inefficient houses. Hundreds of years from now, when BP is forgotten and the gulf wetlands have healed, ocean life will still be affected by the fossil fuels we are burning today.

Cook’s commentary is defensive about how the authors could offend those affected by the BP oil disaster.

I don’t see this as diminishing the devastating impact of the oil spill. It brings home to me the strong visual impact of the oil spill hence the strong public reaction. Climate change is not so easy to process visually, dealing in long-term trends and impacts that stretch on decades and centuries into the future.

At the talk on climate change at the University of Qld, Ove explained the problem with climate change was it’s like littering and the litter not turning up until a decade later. The irony is the impacts from our CO2 emissions will dwarf the impacts of the oil spill.

Toles cartoon

The defensiveness is understandable. This blog initially avoided the entire article because it seemed deprecating to disaster victims, yet came to recognize that the authors attempt to emphasize scale, scope and speed, which for many, is a tough slog.

When this blog last conveyed the concern among oceanographers that Earth’s oceans are losing their ability to absorb carbon dioxide, it reported that human activity—from coal-fired power plants to car tailpipes—is responsible for nearly 30 billion metric tons of carbon dioxide wafting into the atmosphere yearly.

We know that roughly 15 billion metric tons remains in the atmosphere for a century or more. A portion of the rest ends up in the ocean—acidifying saltwater and making the oceans inhospitable to calciferous marine life.

On Facebook, this blog carped about the tagline to the News and Observer article — “It’s not climate change, it’s ocean change!” — since the oceans and weather patterns are highly interrelated. The authors say something likewise within the body of the article: the Gulf oil disaster highlights (and sadly will show for a long time to come) how tightly coupled certain economic activity is to the health of marine ecosystems.

In retrospect, the costs of preventing the spill by installing more reliable safety systems are paltry in comparison to the economic losses in the tourism and fisheries sectors. The same is true for mitigating climate change. Responses that cost less than 1 percent of GDP growth over the next few decades are matched against massive impacts on people and industry, especially in coastal areas of the world.

To paraphrase Kurt Vonnegut, “We could have saved” [Life on the Planet as We know It] “but we were too damned cheap.”

SK commentator Patricia W critiques the authors for still repeating “the long since abandoned target of under 450ppm.”

They also do not mention the effect on the planet’s oxygen supply which ocean acidification will probably cause if it kills off oxygen generating phytoplankton.


“SeaWiFS data show increase in chlorophyl in the oceans which links to loss of primary production.”

In this blog’s not-so-humble opinion, what the authors failed to communicate is the non-linearity implicit in their and others observations about human-caused CO2 emissions. The commentary does get to the idea, although with words like “catastrophe” and “catastrophic.” SK commentator Agnostic gets bonus points for noting the article failed to mention the effects of increased absorption of CO2 creating carbonic acid, particularly in cooler seawater.

These cause depletion of aragonite and other material on which calcifying marine life depends for production of protective shells. This is known to threaten a major marine food source, Pteropods (Thecosomata). Such a wide variety of fish depend on them as their main source of nourishment and consume them in such vast numbers that they have been appropriately described by Dr. Hoffmann (University of California) as ‘chips of the sea’.

Extinction of Pteropods is likely with increased absorption of CO2 and their loss may well threaten marine life which depend on them and, ultimately, humans who depend on marine life as a major source of protein.

While the presence of CO2 does stimulate seagrass growth, providing an enhanced nursery for some marine life, its ability to form carbonic acid poses a threat to corals which provide such an important environment for a wide variety of marine life. The loss of coral reefs endangers marine life on which humans depend.

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3 Comments

  1. jcwinnie
    Posted 2010-7-19 at 8:23 pm | Permalink

    People in the Gulf states have gained membership in a very large club. As Ellen Cantarow puts it, the Gulf Coast joins the Niger Delta, the Ecuador rain forest and elsewhere on our oil-despoiled planet.


    “More oil is spilled in the Niger Delta every year than has been spilled in the Gulf so far.”

    The Niger Delta region, which faces the Atlantic in southern Nigeria, is the world’s third largest wetland. As with shrimp and oysters in the Gulf, so its mangrove forests, described as “rain forests by the sea,” shelter all sorts of crustaceans. The Amazon rain forest, the Earth’s greatest nurturer of biodiversity, covers more than two billion square miles and provides this planet with about 20 percent of its oxygen. We are, in other words, talking about the despoliation-by-oil not of bleak backlands, but of some of this planet’s greatest natural treasures.

  2. jcwinnie
    Posted 2010-7-24 at 6:15 pm | Permalink

    Dominique Browning relays an observation by Professor Jeremy Jackson of the Scripps Institution of Oceanography at UC San Diego. Jackson describes a “shifting baselines syndrome”: “we don’t pay close attention to slow change, even if it is chronic.”

    Our baselines have been shifting with regard to our oceans. We are in danger of forgetting what they used to be like, lowering our standards for what is an acceptable measurement of health.

  3. jcwinnie
    Posted 2010-7-29 at 9:18 am | Permalink

    The warning from San Francisco Treehugger Jaymi Heimbuch is as dire as that from a bicycling elementary school teacher that I know. Heimbuch relays a warning from Nature that “scientists are finding that across the globe, phytoplankton — the food for zooplankton which is food for many other ocean species — is in decline, and that will have massive impacts for not just the marine food chain but ocean systems on the whole.”

    plankton bbc image
    Image via BBC

    The elementary school teacher was much more succinct. Less plankton, less oxygen, which is what we need to breath to live.

    Scientists report in the journal Nature that phytoplankton levels have decreased by about 1% per year as the oceans have warmed. While 1% doesn’t sound like much, consider that the algae species represents about half of all our planet’s photosynthetic biomass (which means it plays a vital role in processing the carbon dioxide out of the atmosphere, acting as microscopic carbon capture and storage units while also producing about half of the planet’s oxygen) and is the basis of the entire oceanic food chain.

    By combining satellite-derived observations of phytoplankton activity from 1997 to 2006 with historical shipboard measurements dating back to the beginning of oceanography, the researchers discovered the downward trend. In the past 60 years, algal biomass has decreased by about 40%, with the rate speeding up in recent years, and the scientists are pointing at ocean warming as the culprit.

    From Nature:

    “Clearly, 40% is a huge number,” says Paul Falkowski, an oceanographer at Rutgers University in New Brunswick, New Jersey. “This implies that the entire ocean system is out of steady state, slowing down.”

    “This is severely disquieting,” adds Victor Smetacek, a marine biologist at the Alfred Wegener Institute of Polar and Marine Research in Bremerhaven, Germany. “One must really digest the very magnitude of this decline and its possible implications.”

    “The study adds to a growing body of global ocean research, all evidencing a fundamentally common result: the net effect of a warming ocean surface is a reduction in phytoplankton surface chlorophyll concentration,” says Michael Behrenfeld, a marine ecologist at Oregon State University in Corvallis.

    The warming of the ocean causes “stratification” — or emphasized differences in the ocean’s layers. Phytoplankton need sunlight from the upper layers and nutrients from the lower layers, and as the ocean stratifies, the nutrients are harder to obtain. However, decreases in arctic areas aren’t necessarily explained by this, and scientists are looking at other factors such as changes in wind and ocean circulation (which also link back to warming oceanic temperatures).

    Whatever the specific reasons, there seems to be no doubt that the levels of phytoplankton are diminishing. Adding the dwindling supply of phytoplankton to the dwindling stocks of fish, changing temperatures, acidification and pollution of the ocean, and we’re looking at a serious problem that may already be impossible to rectify.

    More, mostly Treehugger posts on the topic of Ocean Systems in Peril

    Just remember, boys and girls that money talks and Mister Crotch says Global Warming is Good for You.

    Note: Nature requires a subscription, so I am grateful for Treehugger to re-publish a portion of this important information. There is more at Scientific American online e-zine.

    Gosh, it even made mainstream media, e.g., Associated Press reports that worldwide, levels of plant plankton found in the world’s oceans and crucial to much of life on Earth are declining sharply. “The likely cause is global warming, which makes it hard for the plant plankton to get vital nutrients, researchers say.” How did the Crotch minions let that slip?

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  1. [...] — the food for zooplankton which is food for many other ocean species — is in decline. As authors of a recent Nature article warn, the decline in phytoplankton “will have massive impacts for not just the marine food chain [...]

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