Composition of Particulate Organic Matter in the Southern Chesapeake Bay: Sources and Reactivity

Canuel, Elizabeth A.; Zimmerman, Andrew R.

doi:10.2307/1353077

Cited by 66 publications

(27 citation statements)

References 33 publications

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“…The chl a and PC:PN data (Fig. 6e,j) support earlier findings that indicate organic deposition to upper Bay sediments is refractory terrestrial material, while MB and LB sediments receive more labile phytoplankton detritus (Marvin-DiPasquale & Capone 1998, Canuel & Zimmerman 1999. Spring bloom deposition at MB and LB was indicated by peak chl a concentration in surface sediment during May, and spring was the only season during which organic parameters (chl a and TOM) alone exhibited significant correlations with SR 2 (Table 3), suggesting the linkage between phytoplankton deposition and the rapid response of SR at the sediment surface.…”

Section: Organic Carbonsupporting

confidence: 87%

“…Mesohaline MB sediment is organic-rich, sufidic, highly reducing, non-bioturbated for most of the year, and receives deposited organic matter as mostly autochthonous phytoplankton detritus (Zimmerman & Canuel 2001). Polyhaline LB sediment is oxidized silty sand that is heavily bioturbated by the tubebuilding polycheate Chaetopterus variopedatus (Schaffner 1990) and other organisms, and receives organic matter primarily as phytoplankton detritus (Canuel & Zimmerman 1999). Sites were sampled monthly from March to November (excluding October) during 1989 in order to discern overall monthly and seasonal trends.…”

Section: Introductionmentioning

confidence: 99%

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Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Marvin-DiPasquale

Boynton²,

Capone³

2003

Mar. Ecol. Prog. Ser.

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Seasonal and interannual controls of benthic sulfate reduction (SR) were examined at 3 sites (upper [UB], mid- [MB] and lower [LB] bay) along the Chesapeake Bay central channel, from early spring through fall, for 6 yr (1989 to 1994). The combined influences of temperature, sulfate, organic loading and bioturbation affected seasonal SR rates differently in the 3 regions. Consistently low SR rates at UB resulted from low overlying-water sulfate concentrations and the dominance of refractory organic terrestrial material. Combined seasonal variation in temperature and sulfate accounted for 50% of the annual variability in 0 to 2 cm depth interval SR rates, while sediment organic content had no significant seasonal influence. In contrast, MB and LB sites had high rates of SR fostered by high levels of overlying water SO 4 2 -and organic input dominated by labile phytoplankton detritus. New organic loading (measured as chl a) stimulated 0 to 2 cm SR during spring at both sites. Combined organic quantity (as particulate C and/or N) and temperature accounted for >75% of the variability in 0 to 2 cm SR at MB during spring and fall. Molecular diffusion supplied 25 to 45% of the SO 4 2 -needed to fuel 0 to 12 cm depth interval SR at MB, with the balance presumably supplied by S-recycling. Interannual differences in summertime SR rates were linked to the extent of freshwater flow during spring, with high-flow years associated with high SR rates at UB and MB, and low rates at LB. The negative trend between benthic SR and river flow at LB may result from the upestuary transport of senescing organic matter in bottom water, which increases in the lower reach of the estuary with increasing freshwater inflow.

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Section: Organic Carbonsupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Marvin-DiPasquale

Boynton²,

Capone³

2003

Mar. Ecol. Prog. Ser.

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“…Summary of terrestrial influence biomarkers for marine and river sampling stations. The possible source of the phytosterols is assessed taking into account the percentage of C 29 sterols as well as the sitosterol/cholesterol ratio (Canuel & Zimmerman, 1999). The criteria for classifying the source of organic matter as terrestrial was <25% C 29 and a sitosterol/cholesterol ratio less than 0.5.…”

Section: Discussionmentioning

confidence: 99%

Distribution and sources of phytosterols in coastal and river sediments of south central Chile

Saavedra

Quiñones

Becerra

2014

lajar

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ABSTRACT. Phytosterols are potential endocrine-disrupting compounds. Quantification of phytosterols was carried out in sediments from four coastal zones and two rivers in south-central Chile. Sterol concentrations were determined by capillary gas chromatography-mass spectrometry and the sources of sedimentary organic matter were determined using sterol ratios and lipid biomarkers. Total sterol concentrations (0.03 to 10.4 µg g -1 ) were within the range reported for other marine ecosystems and the β-sitosterol concentration (0.01 to 2.01 µg g -1 ) was lower than previously reported for the upwelling system off Peru. Some coastal stations adjacent to the rivers had β-sitosterol of terrestrial origin. High concentrations of β-sitosterol were also found in sediments from more oceanic stations, supporting the notion that this sterol can also be produced by phytoplankton. No differences in the sterol concentration between the coastal zones were found. However, significant differences were found between almost all coastal zones and both rivers, and between rivers. At the station level and using different biomarkers of the source of organic matter, some areas were found to have a clear terrestrial influence; whereby it is assumed that the source of the phytosterols (especially β-sitosterol) would be vascular plants. The BioBío River and its mouth have a wide variety of sterols and lipids and high levels of cholesterol and epicholestanol, which is possibly related to the presence of domestic effluents derived from large cities. No clear spatial pattern emerge between the location of pulp mill industries and β-sitosterol sediment concentration, with the exception of one station located in the Gulf of Arauco. Keywords: phytosterols, biomarkers, endocrine disruption, pulp mill, Chile. Distribución y fuentes de fitoesteroles en sedimentos costeros y de ríos del centro-sur de Chile RESUMEN. Los fitoesteroles son potenciales disruptores endocrinos. Se cuantificaron fitoesteroles en sedimentos de cuatro zonas costeras y dos ríos en el centro-sur de Chile. Se determinó la concentración de esteroles utilizando cromatografía de gas con espectrómetro de masa y las fuentes de materia orgánica sedimentaria se determinaron utilizando proporciones de esteroles y biomarcadores lipídicos. Las concentraciones de esteroles totales (0,03 a 10,4 µg g -1 ) se encuentran dentro del rango informado para otros ecosistemas marinos y la concentración de β-sitosterol (0,01 a 2,01 µg g -1 ) fue menor que la previamente informada para el sistema de surgencia de Perú. Algunas estaciones costeras adyacentes a los ríos presentaron β-sitosterol de origen terrestre. Además se encontró una alta concentración de este compuesto en sedimentos de estaciones más oceánicas, confirmando que este esterol también puede ser producido por fitoplancton. Al considerar la concentración y presencia-ausencia de esteroles en sedimentos, no fue posible encontrar diferencias significativas entre las cuatro áreas costeras. Sin embargo, se obtuvo una clara diferencia entre la...

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“…Thus, it would appear that microbial respiration leading to hypoxia de pends on a source of organic matter other than in situ phytoplankton production. However, the exact source or sources of this organic material remains unclear at present, and further data are clearly necessary to obtain a full understanding of the input and processing of organic material that is driving this ecosystem, especially considering the following 2 ob servations: (1) the fraction of POM estimated to be represented by phytoplankton (averaged 20.2 ± 11.1%, assuming chl a represents 1.15% of the ashfree dry weight of organic phytoplankton biomass [Reynolds 2006]) is similar to the fraction typically observed in Chesapeake Bay, a eutrophic system driven by phytoplankton production (Canuel & Zimmerman 1999) and (2) the observation, at least on one date, of a large mat-forming diatom (Proboscia alata) occurring in high concentrations during the first hypoxic event of 2009.…”

Section: Discussionmentioning

confidence: 99%

Constrained enrichment contributes to hypoxia formation in Long Bay, South Carolina (USA), an open water urbanized coastline

Sanger¹,

Smith²,

Voulgaris³

et al. 2012

Mar. Ecol. Prog. Ser.

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), but showed significant correlations with spatial variability in particulate nutrient and organic matter concentrations. These observational and modeling results suggest that occurrences of low dissolved oxygen in Long Bay result from regional oceanographic processes that constrain water masses to the nearshore and thus prevent the wider dispersion of local terrestrial inputs. The resulting enhanced material concentrations stimulate heterotrophic oxygen demand, leading to hypoxia in the immediate nearshore waters.

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Composition of Particulate Organic Matter in the Southern Chesapeake Bay: Sources and Reactivity

Cited by 66 publications

References 33 publications

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Distribution and sources of phytosterols in coastal and river sediments of south central Chile

Constrained enrichment contributes to hypoxia formation in Long Bay, South Carolina (USA), an open water urbanized coastline

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