Among coastal systems, coral reefs are thought to be especially
susceptible to the amount of sediment provided by anthropogenic activities
(Smith and Buddemeier, 1992). In Bermuda, Castle Harbour's
history of dredging and landfilling has been linked to increase leaching
of contaminants intowater, sediment, andmarine tissue samples. Results
from this study expand the environmental assessment of impacts from
landfill leaching on the marine environmental by quantitatively demonstrating
elevated metal uptake in corals growing in CH. Relative to the
JSB coral, CH coral Pb, Zn, Mn and Hg concentrations were elevated, in
concertwith previous studies reporting elevated tracemetals in sediment
and water samples near the landfill. The CH record does not reveal a
long-term trend. Instead, coralmetal variability appears to be dominated
by export of contaminants triggered by periodic input. Elevated contaminants
in the surrounding sediment suggest that resuspension is an
important transport medium for transferring heavy metals to corals,
with increased winds accompanied by higher coral variability at CH.
Coupled with wind-induced resuspension, changes in sea level can enhance
export and percolation of contaminants emanating fromthe landfill.
The interplay of natural processes with land-based human activities is
critical to evaluating the potential environmental impact of near shore
contamination. The temporal and spatial comparisons between the CH
and JSB coral records highlight the need to understand these combined
effects and their impacts on coral record interpretation and ultimately
coral health.
Among coastal systems, coral reefs are thought to be especiallysusceptible to the amount of sediment provided by anthropogenic activities(Smith and Buddemeier, 1992). In Bermuda, Castle Harbour'shistory of dredging and landfilling has been linked to increase leachingof contaminants intowater, sediment, andmarine tissue samples. Resultsfrom this study expand the environmental assessment of impacts fromlandfill leaching on the marine environmental by quantitatively demonstratingelevated metal uptake in corals growing in CH. Relative to theJSB coral, CH coral Pb, Zn, Mn and Hg concentrations were elevated, inconcertwith previous studies reporting elevated tracemetals in sedimentand water samples near the landfill. The CH record does not reveal along-term trend. Instead, coralmetal variability appears to be dominatedby export of contaminants triggered by periodic input. Elevated contaminantsin the surrounding sediment suggest that resuspension is animportant transport medium for transferring heavy metals to corals,with increased winds accompanied by higher coral variability at CH.Coupled with wind-induced resuspension, changes in sea level can enhanceexport and percolation of contaminants emanating fromthe landfill.The interplay of natural processes with land-based human activities iscritical to evaluating the potential environmental impact of near shorecontamination. The temporal and spatial comparisons between the CHand JSB coral records highlight the need to understand these combinedeffects and their impacts on coral record interpretation and ultimatelycoral health.
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