Bacterial Utilization of Organic Carbon Produced by Arctic Copepods

Krista Longnecker, Marine Chemistry & Geochemistry
Carin Ashjian, Biology


Arctic Research Initiative
2011 Funded Project


Recent changes in the spatial extent of Arctic sea ice are dramatic. However, the consequences of these changes on biological and chemical processes in the Arctic are not clear. Model results project increases in Arctic phytoplankton that result in an increase in zooplankton biomass. However, we know very little about the bacterial response to these ecosystem changes. Even the question of whether bacteria will convert more or less organic carbon into carbon dioxide is unknown. Zooplankton are one source of organic matter that can be converted by bacteria to carbon dioxide and/or bacterial biomass. This project seeks to determine if organic matter produced by zooplankton, specifically by copepods, will be converted to carbon dioxide by the in situ bacterial community and to quantify the amount of carbon dioxide produced. Any increase in carbon dioxide production by bacteria will decrease the amount of carbon dioxide that can be absorbed by the Arctic Ocean. Since the Arctic is a global sink for carbon, future changes in the ability of the Arctic to absorb carbon has important ramifications for the global carbon cycle. This project is a new and interdisciplinary collaboration between Longnecker and Ashjian. Results from the project will be used as preliminary data for a proposal to be submitted to NSF in 2012.