Biogeochemical characterization of suspended particulate matter in the Columbia River estuary

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 160:173-184 (1997) - doi:10.3354/meps160173 Biogeochemical characterization of suspended particulate matter in the Columbia River estuary F. G. Prahl*, L. F. Small, B. Eversmeyer College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331, USA *E-mail: fprahl@oce.orst.edu In order to understand what controls the composition of suspended particulate material (SPM) in estuarine turbidity maxima (ETM), a set of SPM samples collected in the Columbia River and estuary (northwestern USA) during 3 seasons (fall 1990, summer 1991, spring 1992) was analyzed for detrital mineral (Min), total organic matter [OM, as 2 x particulate organic carbon (POC)], biogenic silica (BSi), chlorophyll a, δ13C, and lignin. In most samples, Min, OM and BSi collectively accounted for 100% of total SPM mass, although their relative importance changed seasonally. The ETM was a trap for organic matter during all 3 seasons, which can explain the intense microbial activity and microcrustacean grazing observed previously. The organic matter was particularly rich in chlorophyll a in late spring to early summer. The source of this seasonal enrichment was mainly riverine phytoplankton. The organic matter contribution to ETM from the ocean was minor compared to the river, but apparently not negligible. Despite large seasonal variations in chlorophyll content, the δ13C of POC concentrated in ETM remained nearly constant between -26 and -25.5o/oo. Vascular plant debris, as depicted by lignin phenol content, always comprised a minor fraction of the organic matter in ETM, although ETM had higher lignin levels than the OM of surrounding waters. Intertidal mudflats are if not an additional source of organic matter at least an important site for transforming riverine organic matter that is ultimately concentrated in ETM. Columbia River estuary · Estuarine turbidity maxima (ETM) · Mudflats · Suspended particulate material (SPM) · Particulate organic carbon (POC) · Chlorophyll · Lignin · Aluminum · Manganese Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 160. Publication date: December 15, 1997 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1997 Inter-Research.