PRINCIPAL 



INVESTIGATOR(S) Donald G. Redalje and Steven E. Lohrenz 



The University of Southern Mississippi 



Center for Marine Sciences 



Building 1103 



Stennis Space Center, Mississippi 39529 



(subcontract to M. Dagg, Louisiana Universities Marine Consortium) 



PROJECT TITLE ASSIMILATION AND TRANSFER OF CARBON IN 



OLIGOTROPHIC AND EUTROPHIC COASTAL WATER 

 COLUMNS 



AMOUNT OF FUNDING FY 1993: $267 K 



SUMMARY OF GOALS 



The overall objective of this program was to determine the amount of fixed carbon in the 

 water column, its forms, its sources, and the rates and mechanisms of formation and removal. 

 We addressed the hypothesis that a greater fraction of the carbon fixed over the shelf escapes 

 respiration in situ and is available for export to the sediments and to the slope. This hypothesis 

 was tested in Louisiana shelf waters of the central Gulf of Mexico. Our observations and 

 conclusions would then be used to revise our hypothesis for subsequent testing in the waters off 

 of Cape Hatteras. 



In the future we plan to expand our study to address the first of these specific objectives 

 with emphasis on determining P-I parameters and optical variability (e.g. spectral absorption and 

 scattering) within the euphoric zone in the Cape Hatteras region with special reference to the 

 absorption and attenuation of light in the 8 wavelength bands which will be utilized by SeaWiFS. 

 In this way we can improve upon our ability to model primary production on similar temporal 

 and spatial scales as those to be used by the FRR fluorometry studies and provide the larger 

 spatial estimates of primary productivity associated with the 1 km and 4 km resolution of 

 SeaWiFS-based production estimates. 



SPATIAL AND TEMPORAL SAMPLING SCALES 



In future studies off Cape Hatteras, we plan to measure primary production on at least two 

 time scales. P-I parameters will be determined using 30 minute incubations. These incubations 

 will be conducted with 5-10 ml samples obtained at sunrise, local noon and near sunset. We will 



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