[Coral-List] From a Keys farmer
Dr. Stephen Jameson
sjameson at coralseas.com
Fri Apr 6 06:04:07 EDT 2007
See the latest issue of Science (30 March 2007, page 1811) for an
interesting research paper by Maoz Fine and Dan Tcherov:
"Scleractinian Coral Species Survive and Recover from Decalcification".
Dr. Stephen C. Jameson, President
Coral Seas Inc. - Integrated Coastal Zone Management
4254 Hungry Run Road, The Plains, VA 20198-1715 USA
Office: 703-754-8690, Fax: 703-754-9139
Email: sjameson at coralseas.com
Web Site: http://www.coralseas.com
Smithsonian National Museum of Natural History
Washington, DC 20560
> Dear Tim:
> I think your observations and questions about CCA growth rates are very
> insightful and worth further research. Mark made the point that
> carbonate saturation state is [partially] controlled by temperature and
> pCO2, which is correct, but these are not the only variables that
> control saturation state. Nor are temperature and saturation state the
> only variables that control calcification rate.
> First, from what I know, there is little information on what controls
> coralline algal growth and calcification, and it would be great to
> supplement your long-term observations with good environmental data from
> your culture site. I can imagine that there are several possible
> environmental changes associated with your autumn "bloom" of CCA, such
> as a decrease in temperature, a change in light regime, a change in
> calcium carbonate saturation state (which is seasonally affected by
> several factors such as alkalinity and temperature), nutrient levels, or
> simply a combination of variables that triggers the algae to grow.
> While there is good evidence that future changes in carbonate chemistry
> will increasingly be a factor in calcification rates (and dissolution
> rates!), given the complexity of these systems, I would hesitate to
> point solely to carbonate chemistry as the trigger for your bloom.
> For example, as temperature drops (and all other variables stay the
> same), the saturation state would actually decrease. But if there is a
> macroalgal bloom going on at the same time, then it is possible that the
> photosynthetic CO2 drawdown would lead to an increase in saturation state.
> Second, the few data on how saturation state might control coralline
> algae calcification rates are confusing. There is some evidence that
> saturation state controls calcification rate (e.g. Chris Langdon's work
> in the Biosphere 2 mesocosm, which was dominated by coralline algae).
> There is other evidence that coralline algae recruitment declines with
> decreasing saturation state. But ongoing experiments (presentation by
> Sophie Martin and JP Gattuso at the ASLO meeting) seem to paint a more
> complicated picture, in which as you suggest, there is an interaction
> between both saturation state AND temperature.
> You make a great point: "It would be interesting to see some large
> scale/long term field research on this topic as we struggle with the
> questions surrounding globally rising temperatures and CO2." Perhaps
> your CCA site is a good candidate for this kind of monitoring! To shed
> light on which factors are stimulating the CCA blooms, this would
> require long-term monitoring of at least temperature, salinity, light,
> saturation state and nutrients. It would also be great if you could
> measure *true* calcification rates rather than extension rates.
> Unfortunately, both carbonate chemistry and calcification rates are
> challenging measurements, and the "Impacts of Ocean Acidification on Coral
> Reefs and Other Marine Calcifiers - Guide for Future Research" that Mark
> and Chuck mentioned provides a summary of those challenges.
> apologies for the lengthy message,
> Joanie Kleypas
> terrasubaqua at peoplepc.com wrote:
>> I would add a personal observation to the global warming discussion based on
>> ten years (~4 one week visits /yr) at the same spot off Plantation Key.
>> There is a fundamental chemistry link between the solubility of calcium salts
>> and water temperature, and we can see the local biochemical link to crustose
>> coralline algae (CCA) growth rate at work each Fall. During this seasonal
>> change, our aquaculture substrate coquina rock gathers a nice coating of CCA
>> over a period of several weeks, commencing just as the water temperature
>> drops. The CCA appears to cover substrate much more rapidly in the Fall
>> months than at any other time of year, it's a very colorful phenomenon and
>> one we watch closely because CCA means added value to our live rock products.
>> We see that, with other variables held to a (roughly) narrow range, the rate
>> of CCA coverage growth seems largely related to the degree of saturation of
>> the calcium salts in the seawater.
>> This may have global ramifications, with global water temperatures rising and
>> considering the significance of calcium carbonate deposition to the global
>> sequestration of carbon dioxide. I wonder how rising water temperatures
>> affect the global deposition of calcium carbonate? Though we might assume
>> from controlled experiments it would be detrimental, some biological factors
>> such as faster overall growth, reproduction rate, and/or coverage of CCA in
>> warmer water, or over water temperature changes spanning particular ranges,
>> might control natural feedback mechanism(s) assisting CCA (and possibly other
>> calcium carbonate 'bio-consumers'?) in global- scale sequestration. Even
>> though CCA seems to grow much more slowly (if at all) in mid-winter at our
>> site, the warmer global water temperatures we encounter may also enhance
>> reproduction or otherwise benefit overall growth over the span of a year. It
>> would be interesting to see some large scale/long term field research on this
>> we struggle with the questions surrounding globally rising temperatures and
>> Tim Birthisel
>> Coral-List mailing list
>> Coral-List at coral.aoml.noaa.gov
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