For example, emissions
inventory showed that municipal solid waste incineration is the most
significant source of Hg emissions in Bermuda, with an estimated
emission of 17 kg/yr and the dump is likely a source of Hg (3.3 kg/yr)
for CH(Peters et al., 2008). Results from this study support the hypothesis
that there is higher bioaccumulation of metals in corals from CH relative
to other areas of Bermuda's nearshore environment (e.g., JSB) that are
exposed to open water. While the landfill has increased to encompass
an area of 0.10 km2 over the last 35 yrs (Jones, 2010), the CH record
does not reveal a long-termtrend. Instead, coralmetal variability appears
to be dominated by export of contaminants triggered by periodic input.
Elevated trace metal concentrations in the sediment of CH relative
to the water samples suggest that the suspended, metal-bearing fine
sediment is a greater source of biologically available metals relative
to the dissolved fraction. Given that fine-grained suspended sediment
accumulates and concentrates metals (Forstner and Salomons, 1980;
Reichelt-Brushett and Jones, 1994), the silt-size sediment in CH may
provide an important transport medium for transferring heavy metals
to corals. Biogeochemical processes can also play a role, for example
elevated coral Zn and Fe levels at CH relative to the sediment may reflect
trophic transfer of nutrients through feeding, where zooplankton
uptake may be a significant source of metal enrichment (