We need to understand ionic mercury better and to distinguish ionic mercury from elemental mercury. Understanding speciation will aid in understanding methylation. Biodiversity is absent at mercury contaminated sites. We should look at what is not there. There is evidence of fish methylating their own mercury.
Sediments contain mostly elemental mercury.
Mercury must be viewed as a systemic contaminant. Selection is a marker. Markers should be used to understand the historical effects of mercury on populations. There is uncertainty in regulation and reaching a consensus is important. An indicator for mercury is needed to measure progress.