Seasonal and spatial variations in the source and transport of sinking particles in the Strait of Georgia, British Columbia, Canada

Johannessen, Sophia C.; O'Brien, Mary; Denman, Kenneth L.; Macdonald, Robie W.

doi:10.1016/j.margeo.2005.01.004

Cited by 54 publications

(50 citation statements)

References 46 publications

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“…3) and, in general, 218 higher mixing rates are associated with higher sedimentation rates ( Table 2). The fluxes of 219 excess 210 Pb (Table 2) high flux at GVRD-6, which was not unexpected given the high vertical flux captured by 222 sediment traps near that location (Johannessen et al, 2005b) and evidence of year-round 223 recirculation and trapping of particles resuspended by tidal currents in the passages to the south 224 (Johannessen et al, 2006). 225…”

Section: Sedimentation Rates Surface Mixing and Geochemical Setting 209mentioning

confidence: 87%

“…However, it is important to remember that 349 fresh, labile OM may be metabolized rapidly in the SML such that it leaves no record at all in the 350 OM sediment profiles. The amount and reactivity of OM reaching sediments varies with water 351 depth (e.g., see Bishop, 1989;Johannessen et al, 2005b) and, although all sources of OC are 352 metabolized to some degree in marine sediments, each source exhibits its own reactivity and 353 metabolic efficiency (e.g., see Goñi et al, 2005). The average OC composition of incident 354 sediment estimated from our sediment profiles (Table 4) Reduced manganese (Mn 2+ ) is soluble, whereas manganese oxides or hydroxides are solid 364 precipitates.…”

Section: Application Of Redox Elements To Organic Cycling In Sedimentmentioning

confidence: 99%

See 1 more Smart Citation

Sediment redox tracers in Strait of Georgia sediments – Can they inform us of the loadings of organic carbon from municipal wastewater?

Macdonald

Johannessen²,

Gobeil³

et al. 2008

Marine Environmental Research

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Section: Sedimentation Rates Surface Mixing and Geochemical Setting 209mentioning

confidence: 87%

Section: Application Of Redox Elements To Organic Cycling In Sedimentmentioning

confidence: 99%

Sediment redox tracers in Strait of Georgia sediments – Can they inform us of the loadings of organic carbon from municipal wastewater?

Macdonald

Johannessen²,

Gobeil³

et al. 2008

Marine Environmental Research

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“…Along the eastern boundary of the strait, near Vancouver, asymmetric tidal currents transport sediment predominantly northward and secondarily southward [18], which is also reflected in contaminant fields emanating from Vancouver's Iona outfall near the Fraser River mouth ( [21] and references therein). Most of the sediment from the Fraser River appears to transport and become trapped in the southern Strait of Georgia, as reflected in suspended particulate distributions [20], sedimentation rates [12,22], and vertical particle flux collected by moored traps [23]. In the northern basin, reduced sedimentation rates of fine material reflect more weathered organic matter, implying greater degradation and longer time spent in oxic waters [24].…”

Section: Introductionmentioning

confidence: 99%

Environmental fractionation of PCBs and PBDEs during particle transport as recorded by sediments in coastal waters

Grant

Johannessen

Macdonald

et al. 2011

Enviro Toxic and Chemistry

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The Strait of Georgia (British Columbia, Canada) is a hydrologically complex inland sea with a rich abundance and diversity of species of aquatic life. Marine sediments, as both a sink for hydrophobic contaminants and a potential source for aquatic food webs, were collected from 41 sites throughout the 6,900-km(2) Strait of Georgia. The congener-specific concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), including BDE-209, were measured. Urban harbors represented hotspots for both PCBs and PBDEs, whereas PBDEs were also found at high concentrations near municipal outfalls. Patterns of PCB distribution were consistent with historical point source emissions in urban areas and environmental distillation toward lighter profiles in remote sites over time. The single congener BDE-209 dominated the PBDEs, accounting for 52% of the average total concentration. However, nonurban deep-water sediment PBDE profiles were both heavier and had higher concentration-weighted average log K(OW) (octanol-water partition coefficient) values compared to shallow samples (percent BDE-209 of total PBDE, 66 versus 32%; log K(OW) , 9.5 versus 8.2, respectively). Collectively, our results suggest that although source signals largely explain PCB and PBDE hotspots in the Strait of Georgia, the combination of physicochemical properties and environmental processes drive divergent compositional fates for the PCBs and the heavier PBDEs in the sediments of the Strait of Georgia.

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“…12). Vertical fluxes of biogenic silica in the central strait show spring and/or fall blooms, but episodic blooms occur from as early as March to as late as October (Johannessen et al 2005b). The δ 15 N and δ 13 C of sinking particles imply that from April to August the opaline silicate flux is produced under bloom conditions, whereas from October to February the flux is supported by slower phytoplankton growth under nutrient-replete, but presumably light-limited, conditions.…”

Section: Phytoplanktonmentioning

confidence: 99%

Effects of local and global change on an inland sea: the Strait of Georgia, British Columbia, Canada

Johannessen¹,

Macdonald²

2009

Clim. Res.

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Global changes manifest themselves in coastal waters depending on local oceanography and ecosystems. In this paper, we consider the Strait of Georgia as a case study. After examining physical and chemical processes and trends, we discuss consequences of change on geochemical cycling and biota. Several components of the system are vulnerable. Declines in pH and O 2 of basin waters, partly imported from the shelf and partly supported by carbon cycling within the strait, could reduce benthic and pelagic habitat. Sea level rise and storms will interact with coastal development to place critical habitat, such as low-lying estuaries, intertidal zones and mudflats, at risk. The decrease and earlier peak in zooplankton biomass may lead to changes in the food web that cascade to higher trophic levels such as fish and birds. Anadromous fish, already showing declines, are vulnerable to ocean regime shifts, increasing river temperatures, habitat destruction, harvesting and contaminants. For southern resident killer whales Orcinus orca, a species at risk, decline in Chinook salmon Oncorhynchus tshawytscha together with marine traffic and biomagnifying contaminants will lead to extirpation if no action is taken. Some stressors can be controlled only through international action to mitigate climate change. However, we have local control of fishing, habitat destruction, release of some contaminants and, to some extent, river flow and temperature. Acting to control these stressors will support resilience of biota in the face of inevitable global changes.

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Seasonal and spatial variations in the source and transport of sinking particles in the Strait of Georgia, British Columbia, Canada

Cited by 54 publications

References 46 publications

Sediment redox tracers in Strait of Georgia sediments – Can they inform us of the loadings of organic carbon from municipal wastewater?

Sediment redox tracers in Strait of Georgia sediments – Can they inform us of the loadings of organic carbon from municipal wastewater?

Environmental fractionation of PCBs and PBDEs during particle transport as recorded by sediments in coastal waters

Effects of local and global change on an inland sea: the Strait of Georgia, British Columbia, Canada

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