Matt Long, 2013 Postdoctoral Scholar


Marine Chemistry & Geochemistry

Coastal Ocean Acidification and Carbon Cycling due to Geochemical and Biological Processes

Across the world about 40% of the human population lives within 100 km of the coast. Therefore, humans are tightly linked to the productivity and stability of coastal systems and their ability to mitigate anthropogenic changes. Specifically, eutrophication in coastal systems leads to increased benthic microbial mineralization that results in a net increase in the acidity or hydrogen ion concentration of sediments and the overlying water column. Combined with increases in ocean acidification and changes in carbon cycling, this yields coastal estuaries that have an uncertain future, but are also ideal for studies of ocean acidification.

Matt Long’s research focuses on ocean acidification in coastal systems to evaluate how these environments will respond to changes in pH and carbon cycling. Ocean acidification is an especially challenging process to evaluate in coastal systems due to the dynamic and high rates of biogeochemical cycling present. This biogeochemical cycling leads to large diel changes in pH, carbonate saturation states, and oxygen concentrations. Matt’s research uses a novel, combined pH and oxygen eddy correlation system that compares metabolic rates (oxygen eddy correlation) with hydrogen ion exchange (pH eddy correlation and supporting measurements). The eddy correlation technique works by correlating high resolution measurements of the vertical water velocity and a solute of interest to examine the flux of a solute across the sediment-water interface. This new technology will enable the examination of acidity changes in the context of high biogeochemical cycling rates in coastal systems. This new pH eddy correlation system also has a number of other important applications such as examining rates of calcification in coastal shellfish and coral species, the role of sediment dissolution in natural carbon sequestration, and how dynamic drivers such as hydrodynamics, light, and other environmental conditions influence these processes.

Matt joined WHOI as an Ocean Acidification Postdoctoral Scholar in June 2013 after receiving his M.S. and Ph.D. at the University of Virginia.  Matt is currently collaborating with Matt Charette, William Martin, and Daniel McCorkle at WHOI.