Acadia University

Quantifying environmental processes that control the fate of mercury and other toxic chemicals in ecosystems

Some of the Research Interests in my Lab Include

Mercury Photo-Reactions in Freshwater, Ocean Water, Soil, and Snow

Why do some remote ecosystems accumulate mercury?

I have collaborated with a variety of researchers to quantify mercury dynamics and speciation at the air- surface interface and the role of solar radiation and temperature in reduction and oxidation processes. These reactions are critical to determining if mercury is retained in an ecosystem and will ultimately accumulate in organisms. We are currently examining similar processes in freshwater, ocean water, soil, and snow.

Dissolved Organic Carbon Structure and effects on Mercury Speciation and UV Attenuation

Does all Carbon affect mercury the same way?

Dissolved organic matter (DOM) is a key variable controlling many biological and abiotoic processes in natural waters. Using field data and controlled experiments we are interested in characterizing DOM in lakes and its effects on mercury speciation.

How does DOC alter UV radiation effects?

The relationship between UV absorbance and dissolved organic matter is key in natural waters. UV is known to instigate a variety of chemical reactions that affect contaminant fate. This is an increasingly important global issue with changes in climate and stratospheric o-zone.

Accumulation of Mercury in Invertebrates and Higher Organisms

Why is mercury accumulating in some organisms and what are the effects?

We know that some show impacts on population such as the Rusty Blackbird or behavior changes such as the common loon. However very little is known about the lower trophic levels leading to these organisms. Several projects are examining invertebrates and key species such as dragonflies in freshwater and polycheates in marine tidal ecosystems. We also have full aquatic food web work being performed in Arctic and temperate locations.  

Mercury and Green House Gas Emissions from Salt Marshes

What happens to mercury in Coastal Wetlands?

Very Little is known about the dynamics of contaminants in coastal environments. Through several collaborations with researchers in IPIMAR Portugal, and with Environment Canada and St FX we are addressing this gap.  Key areas include the role of solar radiation and tidal effects on mercury and green house gas (CO2, CH4, NO2) movements to the atmosphere.