[Vision2020] April 2012: "The Pacific oyster, Crassostrea gigas: Negative Correlation to Elevated CO2 levels: Implications for Ocean Acidification"

Sat Apr 14 13:23:56 PDT 2012

Of all the consequences of global warming that I see mentioned in the 
press, ocean acidification is the one that I find most threatening.  The 
planet has been at much higher concentrations of CO2 before, so I wonder 
just how much of an impact it will have.  It may be large, I don't 
know.  There is some hope that the oceans will prove to be more 
resilient than we give them credit for, though.  Here is a link to a 
report about a study that was done on the Great Barrier Reef that came 
out in the Brisbane Times on Friday:  
http://www.brisbanetimes.com.au/queensland/why-climate-change-might-not-spell-death-for-the-reef-20120412-1wwdb.html

This study took a look at how coral is adapting to warmer temperatures 
and changes in pH levels, and found that while some species are having 
trouble, others are flourishing and adapting to the changes.  That leads 
me to believe that while the particular species of oyster that the 
Whiskey Creek Shellfish Hatchery is using may become unprofitable, there 
may be others that are actually thriving.  I guess I'll have to wait for 
someone to do a study similar to the one described in the Brisbane Times 
on shellfish along the Pacific coast first, though, in order to find out.

Paul

On 04/13/2012 04:23 PM, Ted Moffett wrote:
> The dramatic decline in the Arctic, and impacts of ocean acidification 
> (as the following just published peer reviewed science paper described 
> lower down, as named in subject heading, indicates), are but two among 
> many impacts (increasing floods, fires, drought and eventually faster 
> rate of sea level rise and species extinction) of human sourced CO2 
> emissions and other human activities, that will only increase in 
> magnitude if we as a species do not profoundly alter course in a 
> matter of decades.
> Consider that the impacts we are already witnessing are with only 
> about 40% of the way towards a doubling of atmospheric CO2 level, from 
> about 280 ppm pre-industrial to the current level measured at the 
> Mauna Loa site, ( http://www.esrl.noaa.gov/gmd/ccgg/trends/  ) 394 
> ppm, which shows about at 2 ppm increase in the past year.  At this 
> rate, in 83 years, before the end of this century, humanity will have 
> pushed atmospheric CO2 to about a doubling over pre-industrial levels, 
> to 560 ppm, and another doubling will be underway.  The total 
> planetary reserves of fossil fuels will allow us to go beyond the 
> first doubling of atmospheric CO2 level.
> Global average temperatures have increased about .8 C in the GISS 
> temperature record,
> ( http://data.giss.nasa.gov/gistemp/2011/Fig2.gif ) and if this rate 
> of temperature increase follows the rate of potential atmospheric CO2 
> increase in a business as usual scenario, we will reach over 2 C. 
> increase in global average temperatures by 2100, a level that many 
> climate scientists think will result in unmanageable global impacts, 
> "tipping points", as they say, such as meters of sea level rise from 
> Greenland destabilization.  And of course, with increasing 
> industrialization and demand for energy, it is very possible that 
> human fossil fuel use and CO2 emissions will increase, thus rates of 
> atmospheric CO2 increase will increase, especially if carbon sink 
> reversal increases in magnitude.  Thus it is also within the range of 
> significant scientific probability that global average temperature 
> increase will increase in rate, especially given significant positive 
> feedbacks, reduced albedo from loss of ice cover, especially in the 
> Arctic, among them.
> Good luck, kids!  At 60 now, I certainly won't be around in 2100, 
> without medical breakthroughs.  But some born today will, who will be 
> about 88 in 2100.
> But what I find astonishing is the shrug I have witnesses from the 
> well educated in their middle years (30-50) who are well aware that 
> climate change is happening, who state that it "won't impact them," 
> but will impact the next generation.  Wrong!  Climate change is 
> already impacting us, and in a matter of decades the impacts will 
> significantly increase, so even for someone 60, let alone 30-50, if 
> they live to 90, not so incredible, even they will witness increases 
> in impacts, by 2042.
>  -----------------------------------------------------
> http://www.aslo.org/lo/toc/vol_57/issue_3/0698.html
>
> The Pacific oyster, /Crassostrea gigas/, shows negative correlation to 
> naturally elevated carbon dioxide levels: Implications for near-term 
> ocean acidification effects
>
> Alan Barton, Burke Hales, George G. Waldbusser, Chris Langdon and 
> Richard A. Feely
>
> Limnol. Oceanogr., 57(3), 2012, 698-710 | DOI: 10.4319/lo.2012.57.3.0698
>
> ABSTRACT: We report results from an oyster hatchery on the Oregon 
> coast, where intake waters experienced variable carbonate chemistry 
> (aragonite saturation state < 0.8 to > 3.2; pH < 7.6 to > 8.2) in the 
> early summer of 2009. Both larval production and midstage growth (∼ 
> 120 to ∼ 150 µm) of the oyster /Crassostrea gigas/ were significantly 
> negatively correlated with the aragonite saturation state of waters in 
> which larval oysters were spawned and reared for the first 48 h of 
> life. The effects of the initial spawning conditions did not have a 
> significant effect on early-stage growth (growth from D-hinge stage to 
> ∼ 120 µm), suggesting a delayed effect of water chemistry on larval 
> development.
>
> --------------------------------------------
>
> http://www.sciencedaily.com/releases/2012/04/120411132219.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29 
> <http://www.sciencedaily.com/releases/2012/04/120411132219.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29>
>
>
>   Ocean Acidification Linked to Larval Oyster Failure
>
> ScienceDaily (Apr. 11, 2012) — Researchers at Oregon State University 
> have definitively linked an increase in ocean acidification to the 
> collapse of oyster seed production at a commercial oyster hatchery in 
> Oregon, where larval growth had declined to a level considered by the 
> owners to be "non-economically viable."
>
> A study by the researchers found that elevated seawater carbon dioxide 
> (CO_2 ) levels, resulting in more corrosive ocean water, inhibited the 
> larval oysters from developing their shells and growing at a pace that 
> would make commercial production cost-effective. As atmospheric CO_2 
> levels continue to rise, this may serve as the proverbial canary in 
> the coal mine for other ocean acidification impacts on shellfish, the 
> scientists say.
>
> Results of the research have just been published in the journal, 
> /Limnology and Oceanography./
>
> "This is one of the first times that we have been able to show how 
> ocean acidification affects oyster larval development at a critical 
> life stage," said Burke Hales, an OSU chemical oceanographer and 
> co-author on the study. "The predicted rise of atmospheric CO_2 in the 
> next two to three decades may push oyster larval growth past the 
> break-even point in terms of production."
>
> The owners of Whiskey Creek Shellfish Hatchery at Oregon's Netarts Bay 
> began experiencing a decline in oyster seed production several years 
> ago, and looked at potential causes including low oxygen and 
> pathogenic bacteria. Alan Barton, who works at the hatchery and is an 
> author on the journal article, was able to eliminate those potential 
> causes and shifted his focus to acidification.
>
> Barton sent samples to OSU and the National Oceanic and Atmospheric 
> Administration's Pacific Marine Environmental Laboratory for analysis. 
> Their ensuing study clearly linked the production failures to the CO_2 
> levels in the water in which the larval oysters are spawned and spend 
> the first 24 hours of their lives, the critical time when they develop 
> from fertilized eggs to swimming larvae, and build their initial shells.
>
> "The early growth stage for oysters is particularly sensitive to the 
> carbonate chemistry of the water," said George Waldbusser, a benthic 
> ecologist in OSU's College of Earth, Ocean, and Atmospheric Sciences. 
> "As the water becomes more acidified, it affects the formation of 
> calcium carbonate, the mineral of which the shell material consists. 
> As the CO_2 goes up, the mineral stability goes down, ultimately 
> leading to reduced growth or mortality."
>
> Commercial oyster production on the West Coast of North America 
> generates more than $100 million in gross sales annually, generating 
> economic activity of some $273 million. The industry has depended 
> since the 1970s on oyster hatcheries for a steady supply of the seed 
> used by growers. From 2007 to 2010, major hatcheries supplying the 
> seed for West Coast oyster growers suffered persistent production 
> failures.
>
> The wild stocks of non-hatchery oysters simultaneously showed low 
> recruitment, putting additional strain on limited seed supply.
>
> Hales said Netarts Bay, where the Whiskey Creek hatchery is located, 
> experiences a wide range of chemistry fluctuations. The OSU 
> researchers say hatchery operators may be able to adapt their 
> operations to take advantage of periods when water quality is at its 
> highest.
>
> "In addition to the impact of seasonal upwelling, the water chemistry 
> changes with the tidal cycle, and with the time of day," Hales said. 
> "Afternoon sunlight, for example, promotes photosynthesis in the bay 
> and that production can absorb some of the carbon dioxide and lower 
> the corrosiveness of the water."
>
> A previous study co-authored by Hales found the water that is being 
> upwelled in the Pacific Ocean off the Oregon coast has been kept at 
> depth away from the surface for about 50 years -- meaning it was last 
> exposed to the atmosphere a half-century ago, when carbon dioxide 
> levels were much lower. "Since atmospheric CO_2 levels have risen 
> significantly in the past half-century, it means that the water that 
> will be upwelled in the future will become increasingly be more 
> corrosive," Hales said.
>
> The OSU researchers also found that larval oysters showed delayed 
> response to the water chemistry, which may cast new light on other 
> experiments looking at the impacts of acidification on shellfish. In 
> their study, they found that larval oysters raised in water that was 
> acidic, but non-lethal, had significantly less growth in later stages 
> of their life.
>
> "The takeaway message here is that the response to poor water quality 
> isn't always immediate," said Waldbusser. "In some cases, it took 
> until three weeks after fertilization for the impact from the acidic 
> water to become apparent. Short-term experiments of just a few days 
> may not detect the damage."
>
> The research has been funded by a grant from the National Science 
> Foundation, and supported by NOAA and the Pacific Coast Shellfish 
> Growers Association. Other authors on the journal article include 
> Chris Langdon, of OSU's Hatfield Marine Science Center, and Richard 
> Feely, of NOAA's Pacific Marine Environmental Laboratories.
>
> -----------------------------------------
>
> Vision2020 Post: Ted Moffett
>
>
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