PRINCIPAL 



INVESTIGATOR(S) Paul G. Falkowski 



Oceanographic and Atmospheric Sciences Division 

 Brookhaven National Laboratory 

 Upton, NY 11973 



PROJECT TITLE ASSESSING THE FACTORS CONTROLLING THE 



MAGNITUDE, VARIABILITY, AND FATE OF PRIMARY 

 PRODUCTION ON OCEAN MARGINS 



AMOUNT OF FUNDING FY 1994: $524 K 



SUMMARY OF GOALS 



Although continental ocean margins represent only 12% of the surface area of the world's 

 oceans, they account for between 25 and 45% of the ocean primary production. This production 

 is a consequence of photosynthetic energy conversion of inorganic carbon to particulate organic 

 carbon. The processes regulating the sources and fates of primary production are multiple and 

 interactive; they include intrinsic biological processes and extrinsic physical, chemical, and 

 biological processes. Anthropogenic activities can affect these processes both directly and 

 indirectly. Overall this effort contains two projects, one of which focusses on the intrinsic 

 biological regulation of phytoplankton photosynthesis and the other which focusses on the 

 extrinsic factors related the magnitude and fate of production. The specific goals of these efforts 

 within the Ocean Margins Program are: 



1) To provide the basic (i.e., core) measurements of (a) primary production based on radiocarbon 

 assimilation, (b) spectral irradiance, (c) chlorophyll a, (d) particulate carbon and nitrogen, (e) 

 optical properties of the particulates, and (f) descriptions of species compositions for selected 

 areas and times. 



2) To develop primary production models based on parameters derived from (1) and in 

 collaboration with Kolber and Wirick (using measurements of variable fluorescence) that can "fill 

 in" for spatial and temporal gaps in ship-based sampling. 



3) To assess the residence time, turnover time and natural death rate of phytoplankton on the 

 continental shelf. 



4) To develop and integrate new biological and molecular methods to diagnose factors 

 intrinsically limiting phytoplankton photosynthesis and to use these techniques in conjunction 

 with conventional methods to assess the importance of "bottom-up" and "top-down" controls. 



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