Measuring phytoplankton carbon: A new method for the isolation and elemental analysis of microalgae to validate satellite derived estimates

Jason Graff, Oregon State University, jrgraff@science.oregonstate.edu (Presenter)
Allen Milligan, Oregon State University, allen.milligan@science.oregonstate.edu
Michael Behrenfeld, Oregon State University, mjb@science.oregonstate.edu

Phytoplankton are one of a multitude of particle types in the marine environment that contribute to the particulate organic carbon (POC) pool. Previous methods for the elemental analysis of phytoplankton rely on collecting marine particles onto filters, but suffer from unconstrained signatures of bacteria, detritus, and other particles. Alternatively, it has been common to assume that chlorophyll concentration was indicative of phytoplankton carbon (C_phyto), but this approach suffers from unconstrained physiological variability in intracellular pigment in response to variable light and nutrient conditions. Recently, optical properties such as beam attenuation and backscattering have been used to assess C_phyto. However, these values too are not well constrained because of undescribed variability in the particle size distribution and lack of field validation data for algorithm parameterization.

We introduce a method that uses flow cytometry to isolate phytoplankton from the total particle field. Phytoplankton are identified by their fluorescence signatures and sorted away from the bulk sample. The collected cells are then analyzed for carbon and nitrogen using high temperature combustion methods. The acquisition of accurate phytoplankton carbon and nitrogen data using this method will 1) benefit remote sensing applications, validating phytoplankton carbon estimates from space, 2) improve our knowledge of phytoplankton stoichiometry, and 3) provide a better understanding of the response of phytoplankton to environmental forces.

Presentation Type:  Poster

Session:  Other   (Tue 11:30 AM)

Associated Project(s): 

• Related Activity

Poster Location ID: 183