PRINCIPAL 



INVESTIGATOR(S) Gustav-Adolf Paffenhofer and Peter G. Verity 



Both at: Skidaway Institute of Oceanography 



10 Ocean Science Circle 

 Savannah, GA 31411 



PROJECT TITLE IMPACT OF PROTO- AND METAZOOPLANKTON ON THE 



FATE OF ORGANIC CARBON IN CONTINENTAL OCEAN 

 MARGINS 



AMOUNT OF FUNDING FY 1994: $274 K 



SUMMARY OF GOALS 



Metazooplankton remove particulate organic carbon from the ocean by ingestion, and they 

 produce organic carbon by growth, reproduction, excrementation and excretion. Our approach 

 is to quantify ingestion by abundant metazooplankton not only of phytoplankton carbon but also 

 of heterotrophic nano- and microplankton which have been shown repeatedly to be a major food 

 source of planktonic copepods. Simultaneously, biomass, egg production and fecal pellet 

 production will be quantified for the same abundant to dominant zooplankton taxa. 



The nano/microplankton component of this joint project includes both laboratory technical 

 development and field applications. Technique development comprises two subsections: 

 improvement of our existing color image analysis system to quantify composition, size 

 distribution, and carbon biomass of photosynthetic and heterotrophic nano- and microplankton; 

 and evaluation of the efficacy of an immunochemical assay to measure predation by (gelatinous) 

 macrozooplankton on protozoan zooplankton. These tools would subsequently be used off Cape 

 Hatteras to determine (1) the apportionment of living and non-living POC into phytoplankton and 

 heterotrophic components, (2) carbon ingestion by nano- and microzooplankton, and (3) the 

 transfer of the living POC to higher trophic levels. 



SPATIAL AND TEMPORAL SAMPLING SCALES 



Our Multiple Net System (MNS) was designed to quantitatively collect larger and smaller 

 metazooplankton. It now can be operated to a depth of 300 m, can hold up to 6 nets, and can 

 be deployed in 20 to 30 minute intervals, depending on the maximum depth of sampling; we can 

 easily sample at 5 km intervals. Zooplankton grazing experiments aboard ship should be 

 conducted over 24 h, with 2 experiments run simultaneously. The CritterCam, an in situ movie 

 camera, arrived several weeks ago. It will be repeatedly field-tested during the second half of 

 1994, and is intended to be deployed eventually for observations over days to weeks to quantify 



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