Resuspension-induced partitioning of organic carbon between solid and solution phases from a river–ocean transition

Ž . Laboratory experiments were conducted to evaluate the net exchange of organic carbon OC between sediments and overlying water during episodes of resuspension. Surface sediment samples collected from six locations within the Hudson River Estuary and the Inner New York Bight were resuspended in their respective bottom waters for periods ranging from 30 Ž . s to 2 h. After resuspension, dissolved organic carbon DOC concentration generally reached levels greater than that predicted by conservative mixing of pore water and bottom water, indicating net release of OC from the sediment particles. The amount of OC released during the 1-h extractions comprised F0.1% of the total sediment pool, but correlated Ž 2 . Ž . positively R s0.65, P-0.052 with the amount of particulate organic carbon POC found in the high-density fraction of the sediment matrix. This suggests that the mineral-bound fraction of sedimentary OC was the major source for the excess Ž . DOC released into solution, and that across various sedimentary environments, only a small but fairly constant fraction of the total sedimentary POC may be poised for rapid transfer to the water column. q 2001 Elsevier Science B.V. All rights reserved.