CALORIC CONTENT OF SINKING PARTICULATE MATTER IN THE NORTH PACIFIC SUBTROPICAL GYRE
The oceanic biological carbon pump transfers atmospheric carbon dioxide to the deep-sea via primary production, particle export and organic matter remineralization. Decades of investigations have shed light on the enormous role marine microorganisms play in solar energy capture, organic matter transformation, and the cycling of bioessential elements including carbon (C), hydrogen (H), nitrogen (N), phosphorus (P) and sulfur (S). To our knowledge, with the exception of only a single published data set three decades ago, the caloric content of sinking particulate matter—the energy available to fuel life processes below the euphotic zone—has eluded direct measurement. Recently, long-duration sample collection of sinking particles and optimization of semi-micro calorimeter sample analysis has enabled direct measurements of caloric content. Here we will present the first depth profile (12 depths; 100-500 m) of the caloric content (and CHNP values) of sinking particulate matter at Station ALOHA, an oligotrophic field station in the North Pacific Subtropical Gyre. This assessment provides more comprehensive characterization of sinking particles in the euphotic zone and exported particulate matter. Comparing these data to the CHNP and caloric content of the living planktonic assemblage provides new insight into the consumption and degradation of sinking organic matter. More broadly, this investigation adds to the understanding of energy flux within the ocean.
Grabowski, E. M., Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai’i, USA, email@example.com
Karl, D. M., Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai’i , USA, firstname.lastname@example.org
Time: 15:30 - 16:30
Location: Poster/Exhibit Hall
Presentation is given by student: No