Sources and Composition of Organic Materials in Waters and 

 Sediments of the Southern California Coastal Zone 



Williams, P.M. 



$107,000 



University of California/San Diego 



Scripps Institution of Oceanography 



C: 619-452-2929 



The project objective is to determine the sources, composition, and fate of naturally occurring organic substances 

 in shelf, slope, and basin waters and in sediments of the California Bight coastal zone. The isotopic and chemical 

 characteristics of the sedimentary, dissolved, and suspended and sinking particulate organic phases are analyzed. It 

 is expected to determine (1) the relative fluxes of terrestrially and marine-derived organic substances to the coastal 

 waters and sediments; (2) whether the qualitative and quantitative changes in the composition of various organic 

 phases reflect specific biochemical processes occurring in the sediments and water column; (3) whether changes in 

 isotopic ratios can be used to interpret the magnitude of terrestrial versus marine contributions; and (4) whether 

 radiocarbon dating of organic phases is useful for interpreting organic processing. 



Utilization, Cycling, and Vertical Transport of Particulate Organic 

 Matter in the Marine Coastal Environment 



Landry, M.R. 



$107,000 



University of Hawaii 



Department of Oceanography 



C: 808-948-7776 



The project objective is to elucidate the roles of planktonic animals and protozoa in (1) the utilization of surface- 

 produced particulate organic matter (POM) and (2) the transport and cycling of POM through the water column 

 overlying the Santa Monica Basin. We use sediment traps to quantify the rates of flux of phytoplankton pigments, 

 carbon, nitrogen, and biogenic silica. We conduct experimental studies on shipboard to assess process rates of 

 various components of the grazer community, including the gut fluorescence technique for macrozooplankton and 

 the dilution, metabolic inhibitors, and fluorescently labeled bacteria techniques for planktonic ciliates and flagel- 

 lates. Many of the organisms characterized as macrozooplankton on the basis of size function similarly to 

 microzooplankton by producing slowly settling fecal debris, versus rapidly settling pellets as generally assumed for 

 macrozooplankton. Such debris is subject to metabolism and degradation within the euphotic zone. The daily flux 

 of phytoplankton from the euphotic zone is in the range of 20 to 40 percent of daily production as measured by C 

 and approximately 10 percent of particulate carbon, implying a particle residence time of 10 days. 



Coastal Ocean Margins Program A22 December 1988 



