Metal concentrations in surface sediments of boston harbor—Changes with time

Bothner, Michael H.; Brink, Marilyn R. Buchholtz ten; Manheim, Frank T.

doi:10.1016/s0141-1136(97)00027-5

Cited by 107 publications

(62 citation statements)

References 26 publications

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“…Cores (internal diameter of 10.7 cm) with nearly undisturbed sediment-water interfaces were obtained using a hydraulically damped slow gravity corer (Bothner et al, 1997;Bothner et al, 1998) at ten locations (crosses in Fig. 1).…”

Section: Sediment Characteristicsmentioning

confidence: 99%

Sediment transport on the Palos Verdes shelf, California

Férré

Sherwood

Wiberg

2010

Continental Shelf Research

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a b s t r a c t Sediment transport and the potential for erosion or deposition have been investigated on the Palos Verdes (PV) and San Pedro shelves in southern California to help assess the fate of an effluent-affected deposit contaminated with DDT and PCBs. Bottom boundary layer measurements at two 60-m sites in spring 2004 were used to set model parameters and evaluate a one-dimensional (vertical) model of local, steady-state resuspension, and suspended-sediment transport. The model demonstrated skill (Brier scores up to 0.75) reproducing the magnitudes of bottom shear stress, current speeds, and suspended-sediment concentrations measured during an April transport event, but the model tended to underpredict observed rotation in the bottom-boundary layer, possibly because the model did not account for the effects of temperature-salinity stratification. The model was run with wave input estimated from a nearby buoy and current input from four to six years of measurements at thirteen sites on the 35-and 65-m isobaths on the PV and San Pedro shelves. Sediment characteristics and erodibility were based on gentle wet-sieve analysis and erosion-chamber measurements. Modeled flow and sediment transport were mostly alongshelf toward the northwest on the PV shelf with a significant offshore component. The 95th percentile of bottom shear stresses ranged from 0.09 to 0.16 Pa at the 65-m sites, and the lowest values were in the middle of the PV shelf, near the Whites Point sewage outfalls where the effluent-affected layer is thickest. Long-term mean transport rates varied from 0.9 to 4.8 metric tons m À 1 yr À 1 along the 65-m isobaths on the PV shelf, and were much higher at the 35-m sites. Gradients in modeled alongshore transport rates suggest that, in the absence of a supply of sediment from the outfalls or PV coast, erosion at rates of $ 0.2 mm yr À 1 might occur in the region southeast of the outfalls. These rates are small compared to some estimates of background natural sedimentation rates ( $ 5 mm yr À 1 ), but do not preclude higher localized rates near abrupt transitions in sediment characteristics. However, low particle settling velocities and strong currents result in transport length-scales that are long relative to the narrow width of the PV shelf, which combined with the significant offshore component in transport, means that transport of resuspended sediment towards deep water is as likely as transport along the axis of the effluent-affected deposit.Published by Elsevier Ltd.

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Section: Sediment Characteristicsmentioning

confidence: 99%

Sediment transport on the Palos Verdes shelf, California

Férré

Sherwood

Wiberg

2010

Continental Shelf Research

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“…Harbor (Bothner et al, 1998 Like all of Boston Harbor, this site has a complex depositional history. In 1978, the sedimentation rate was determined to be 1.8 cm y -1 (Bothner et al, 1998 The major input of organic matter to the seafloor is from local primary production (Taylor, 2005;Libby et al, 2004a,b).…”

Section: Study Sitementioning

confidence: 99%

“…In 1978, the sedimentation rate was determined to be 1.8 cm y -1 (Bothner et al, 1998 The major input of organic matter to the seafloor is from local primary production (Taylor, 2005;Libby et al, 2004a,b). Primary production at a nearby harbor site north of Peddocks Island ranged from 2600-4900 µmol C cm -2 y -1 from [2001][2002][2003], with the highest value in 2002 and the lowest in 2003.…”

Section: Study Sitementioning

confidence: 99%

Insights on geochemical cycling of U, Re and Mo from seasonal sampling in Boston Harbor, Massachusetts, USA

Morford

Martin

Kalnejais

et al. 2007

Geochimica et Cosmochimica Acta

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3Benthic chamber experiments including the nonreactive solute tracer, Br -, indicated that sediment irrigation was very important to solute exchange at the study site.The enhancement of sediment-seawater exchange due to irrigation was determined for the nonreactive tracer (Br -), TCO 2 , NH 4 + , U and Mo. The comparisons between these solutes showed that reactions within and around the burrows were very important for modulating the Mo flux, but less important for U. The effect of these reactions on Mo exchange was highly variable, enhancing Mo (and, to a lesser extent, U) uptake at times of relatively modest irrigation, but inhibiting exchange when irrigation rates were faster.These results reinforce the observation that Mo can be released to and removed from pore waters via sedimentary reactions.The removal rate of U and Mo from seawater by sedimentary reactions was found to agree with the rate of accumulation of authigenic U and Mo in the solid phase. The fluxes of U and Mo determined by in situ benthic flux chamber measurements were the largest that have been measured to date. These results confirm that removal of redoxsensitive metals from continental margin sediments underlying oxic bottom water is important, and suggest that continental margin sediments play a key role in the marine budgets of these metals.4

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“…Coastal sediments are considered to be a major sink for, and also a secondary source of pollutants. The fate of contaminants in sediments depends on a number of factors, including the resuspension, bioturbation, and diagenesis of sediments (Bothner et al, 1998;Lee and Cundy et al, 2001). Heavy metals, unlike other pollutants, are not biodegradable and can accumulate in sediments over time.…”

Section: Introductionmentioning

confidence: 99%

The spatial and temporal distribution of heavy metals in sediments of Victoria Harbour, Hong Kong

Tang

Zhang

et al. 2008

Marine Pollution Bulletin

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Victoria Harbour has received substantial loadings of pollutants from industrial and municipal wastewater discharged since the 1950s. Inputs of contaminants have declined dramatically during the last two decades as a result of better controls at the source and improved wastewater treatment facilities. To assess the spatial and temporal changes of metal contaminants in sediments in Victoria Harbour, core and grab sediments were collected. The central harbour areas were generally contaminated with heavy metals. The spatial distribution of trace metals can probably be attributed to the proximity of major urban and industrial discharge points, and to the effect of tidal flushing in the harbour. In the sediment cores, the highest concentrations of trace metals were observed to have accumulated during the 1950s to 1980s, corresponding with the

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Metal concentrations in surface sediments of boston harbor—Changes with time

Cited by 107 publications

References 26 publications

Sediment transport on the Palos Verdes shelf, California

Sediment transport on the Palos Verdes shelf, California

Insights on geochemical cycling of U, Re and Mo from seasonal sampling in Boston Harbor, Massachusetts, USA

The spatial and temporal distribution of heavy metals in sediments of Victoria Harbour, Hong Kong

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