Seasonal variation in the quality of dissolved and particulate organic matter exchanged between a salt marsh and its adjacent estuary

Abstract

Fluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base-extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base-extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components (C) modeled, C3 represented recalcitrant DOM and C4 represented fresher soil-derived source DOM. Component 1 represented detrital POM, and C6 represented planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m À2 yr À1 and labile DOC export was 49 g C m À2 yr À1 ; no planktonic DOC was exported. The marsh also exported 41 g C m À2 yr À1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m À2 yr À1 . Assuming the exported organic matter was oxidized to CO 2 and scaled up to global salt marsh area, respiration of salt marsh DOC and POC transported to estuaries could amount to a global CO 2 flux of 11 Tg C yr À1 , roughly 4% of the recently estimated CO 2 release for marshes and estuaries globally.

Shifts in the Source and Composition of Dissolved Organic Matter in Southwest Greenland Lakes Along a Regional Hydro‐climatic Gradient

“…DOM quality in the lakes could also be described by a six‐component PARAFAC model of DOM fluorescence (Figure S3). The spectral characteristics of the six components were matched to 50 models in the OpenFluor database (accessed 17 December 2016) and assignments of each component are discussed in more detail in the supporting information (Table S3) (Gonçalves‐Araujo et al, ; Kothawala et al, ; Lapierre & Del Giorgio, ; Osburn et al, ; Stedmon et al, ; Williams et al, ; Yamashita et al, ). The first three components of the PARAFAC model exhibited spectral features consistent with largely allochthonous sources of DOM to lakes (Aiken, ; Fellman et al, ; Senesi, ; Wünsch et al, ).…”

Release and Microbial Degradation of Dissolved Organic Carbon and Nitrogen from Phragmites australis and Suaeda salsa in the Wetland of the Yellow River Estuary

“…CDOM is the optically measureable component of DOM and is important for most photochemically-mediated processes in coastal waters [22,23]. It plays important roles in carbon cycle and biogeochemical processes in estuarine and coastal water [24,25]. Despite a large amount of DOC is produced from salt marsh and wetland plants, the chemical composition and bioavailability of DOC and CDOM produced from different plant species have not been well studied and there is limited knowledge on exactly how these DOC and CDOM pools are recycled in coastal waters.…”

Journal of South Carolina Water Resources

“…However, this level of understanding (e.g., outlier determination, or multi-parameter correlations) would require a longer data record and more extensive parameterization than are presently available for Bull Creek. Additional sampling and characterization may also uncover seasonal patterns that need to be accounted for, such as changes in terrestrial carbon and PAH sources and primary in-stream productivity and plankton assemblages (Osburn et al, 2015;Reed et al, 2015). While TSS versus turbidity correlations have been established for tidal creek salt marsh systems in other studies (Suk et al, 1998), it is possible that the impact of urbanization and stormwater complicates this approach, especially in smaller watersheds.…”