Organic geochemistry seeks to understand the role of organic matter in the geosphere:  how reduced carbon, nitrogen and other elements are produced, cycled, and regulate major planetary biogeochemical cycles.  A main focus is developing new molecular and isotope approaches which can be used to trace both biological and geochemical cycles.

The McCarthy Lab’s research centers on creating novel molecular-level organic and isotope approaches to understand major biogeochemical cycles in the sea, with a focus on how organic molecules record biological and geochemical processes.  New method development underpins almost all of our work, focusing on two broad areas:  1) compound-specific isotope analysis of individual amino acids (CSIA-AA), for tracing organic nitrogen source, diagenesis, food web and  paleo-processes, and 2) radiocarbon (D¹⁴C) applications to unravel the cycling rates of organic nitrogen, as well as “uncharacterizable” organic materials. 

Current  research  includes collaborative  efforts in multiple areas including:  ocean dissolved organic matter,  paleoceanography, organic geochemistry of nitrogen in both sediments and the water column, ocean ecology, and new CSIA-AA development and applications in such fields as archaeology, estuarine, and deep-sea research.