PRINCIPAL 



INVESTIGATOR(S) Robert C. Aller, Josephine Y. Aller, J. Kirk Cochran, and Cindy Lee 



All at: Marine Sciences Research Center 



SUNY Stony Brook 

 Stony Brook, NY 11794-5000 



PROJECT TITLE MULTIPLE TRACER MEASUREMENT OF THE COUPLING 



BETWEEN BENTHIC CARBON FLUXES AND 

 BIOTURBATION ACTD/ITY DURING THE "SPRING 

 BLOOM" 



AMOUNT OF FUNDING FY 1994: $97 K 



SUMMARY OF GOALS 



Our primary goals are to quantify and model: 1) the net fluxes of reactive biogenic debris 

 (planktonic C org , Si0 2 , CaC0 3 ) to the seafloor, 2) the resulting net sedimentary remineralization 

 rates (N, XC0 2 , Mn), and 3) associated benthic community activities which partially control 

 remineralization, including bioturbation, benthic shell deposition, and microbial 

 abundance/biomass production. The emphasis is on fluxes of sedimentary material and processes 

 with characteristic reaction or transport timescales of several weeks to months, corresponding 

 to and integrating over major nonsteady-state seasonal water column events such as plankton 

 blooms or storms. These timescales lie between those typically addressed in high resolution 

 water column studies (hrs.days) and the longer term burial fluxes elucidated by deeper sediment 

 properties (yrs, Kyrs). Methodologies (see below) are centered on solid phase reactive or natural 

 tracer constituents in surface sediments, such as chloropigments and 234 Th, for which 

 decomposition kinetics are either known or can be relatively accurately inferred, and which allow 

 model conversion of measured sedimentary inventories into mass flux estimates. The methods 

 employed are particularly amenable to functional spatial mapping and thus are useful in complex 

 regions where variability requires relatively dense sampling to accurately resolve patterns. The 

 primary measurements proposed are an appropriate adjunct to direct measurements of solute 

 fluxes such as benthic 2 , XC0 2 , and nutrient fluxes, to made primarily by other investigators. 



SPATIAL AND TEMPORAL SAMPLING SCALES 



Spatial sampling scales and distribution are yet to be determined (see Status of Research) 

 but 20 - 25 stations per cruise (~10 d), depending on the exact constellation of measurements, 

 represents present capacity. Determination of station sites will be made in conjunction with 

 other investigators based on total program goals. Because substantial benthic delivery of biogenic 



