Size-fractionated particulate organic matter and chlorophyll on the Mississippi-Alabama Shelf in Fall 2015

The total particulate organic carbon (POC), organic nitrogen (PON) and chlorophyll a (Chl a) are all proxies for planktonic biomass. POC and PON include contributions from bacteria, zooplankton and phytoplankton; however, Chl a is operationally considered to be solely from phytoplankton (assumes no substantial Chl a from microzooplankton kleptoplasty). Size-fractioning these bulk particulates provides information regarding the distribution of biomass among large and small cells. Such information is useful for biogeochemical modelers who typically divide plankton into groups based on size.