SEMINAR: MBF 602 seminar-Nancy Muehllehner Friday, April 23rd, 2010 4:00pm S/A seminar room

[Cary Rios <crios@rsmas.miami.edu>]

The potential role of variable coastal carbonate chemistry on predictions of coral reef decline due to ocean acidification

 

As the oceans acidify and lab studies show significant decreases in coral calcification rates, the subsequent goal of predicting ecosystem level effects faces considerable challenges.  The current study represents the first survey of carbonate chemistry across the Florida Reef Tract, establishing a baseline of reef metabolism against which the possible impacts of ocean acidification can be judged.  Measurements of total alkalinity (TA) and dissolved inorganic carbon (DIC) were started in April 2009 on the first of 6 cruises along eight onshore-offshore transects stretching from Key West to Key Largo.  The drawdown of salinity normalized TA (nTA) and DIC (nDIC) across the reef averaged 53.4 ± 29.4 μmol kg^-1 and 86 ± 45 μmol kg^-1, respectively.  The current analysis of the drawdown of nTA and nDIC relative to their offshore values provides an estimate of the relative rates of calcification and net photosynthesis across each of the reef tracts.  These data have been used to compute and compare inshore and offshore aragonite saturation states (Ω) and reveal a close association between Ω and net community production, potentially driving rates of community calcification.  If coastal photosynthesis is playing a more dominate role in determining the carbonate chemistry of the Florida Reef Tract, and this trend is consistent over future cruises, then predictions of the effect of ocean acidification would have to be substantially altered to accommodate these mitigating effects.  In addition, this important baseline data provides an estimate of reef health that can contribute to our understanding of how reefs respond to changing temperature and ocean acidification over longer time periods.

 

BS University of Delaware

MS California State University, Northridge

2^nd year PhD student: Nancy Muehllehner,

Advisor: Chris Langdon

Cary Rios 
Graduate Studies Office
University of Miami
Rosenstiel School of Marine & Atmospheric Science
4600 Rickenbacker Cswy

S/A 132
Miami, FL 33149
Locator Code: VK
P. 305.421.4920
F. 305.421.4771
http://www.rsmas.miami.edu
crios@rsmas.miami.edu 

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