What is the estimated annual tonnage of carbon dioxide absorbed by
molluscs in the formation of their calcium carbonate shells?
Hi knowitall22,
Well, an interesting question but not one that lends itself to an easy
answer.
We couldn't find reference to molluscs in particular, most of the
information pertains to all calcium carbonate building organisms (for
example, foramaniferans) but you may find this information on the
carbon cycles helpful in your search for the answer. You'll find that
approximately 50 billion tons of carbon (183 billion tons of carbon
dioxide*) enters the water from the atmosphere. The organisms that use
the carbon dioxide, give off about 40 billion tons carbon (146 billion
tons of carbon dioxide) through their metabolism, which is a net
uptake of 10 billion tons by ocean life. After the organisms die, the
calcium carbonate of their shells continue to exist. Part of the
calcium carbonate disolves back into the water and the rest
precipitate to the ocean floor where it becomes part of ocean
sediments. The net rate at which this occurs is .2 billion tons of
carbon per year (.73 billion tons of carbon dioxide). So, if you are
asking what the net removal of carbon dioxide from the atmospheric
sink is through biological processes in the ocean into the sedimentary
sink, the answer would be .73 billion tons of carbon dioxide. But keep
in mind that eventually the calcium carbonate will again become part
of the atomosphere through the weathering of limestone and volcanic
activity.
*The equivilent weight of carbon in carbon dioxide can be calculated
by multiplying the weight in carbon by the molecular weight of carbon
dioxide divided by the molecular weight of carbon, so the weight in
carbon multiplied by
[16 + 2 x 12] / 12 = the equivilent weight in carbon dioxide.
Additional Links:
The Carbon Cycle:
http://www.geog.ouc.bc.ca/physgeog/contents/9r.html
noaa research: see figure one:
http://www.oar.noaa.gov/spotlite/archive/spot_carbon.html
We're glad to hear this is what you were looking for - thank you for
letting us know. Wishing you the best in the New Year -
Sincerely,
hummer
Search Strategy:
None. My son, a university wildlife biology student, is home for the
holidays and took a special interest in your question.
 Walking/Running Puppy - Advise needed
 GridPanel border
|
carbon dioxide sink