HR: 08:45h
AN: B51D-04    [Abstracts]
TI: Phosphorus forms and controls on phosphorus dynamics in sediments from Monterey Bay, California
AU: * Cade-Menun, B J
EM: bcade.menun@gmail.com
AF: Dept. of Geol. & Envir. Sci., Stanford University, Bldg 320, Rm 118, Stanford, CA 94305- 2115, United States
AU: Paytan, A
EM: apaytan@ucsc.edu
AF: Institute Marine Sci., UC Santa Cruz, 1156 High St., Santa Cruz, CA 95064, United States
AB: Phosphorus is an essential element for all organisms. Phosphorus can be removed from the water column as sinking particulate matter, where it may either be buried or remineralized and released to the water column. The objective of our study was to determine P forms, dynamics and variability in sediment samples from Monterey Bay, CA. Six pushcore samples were randomly collected from a 2-m2 area, and were divided into 4 layers, each 1.5-2.5 cm thick. Samples were analyzed for total P, C and N, P forms by 31P NMR spectroscopy and SEDEX fractionation, phosphatase activity, and P retention. Total P, C and N did not change with depth, but there were significant changes with depth for P forms by NMR and SEDEX, and well as alkaline phosphatase and diesterase activity. However, P retention was strong in all layers and increased with depth, suggesting that remineralized P not taken up by organisms is sorbed onto sediment minerals rather than released to the surface water.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0419 Biomineralization
DE: 0460 Marine systems (4800)
DE: 0470 Nutrients and nutrient cycling (4845, 4850)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting