Methods:
In this study, we will sample aquatic insect larvae at three different sites along the Douglas Lake (West, South, East) and collect adult insects as they emerge out of the water. After the terrestrial organisms have enough time to consume the emergent insects, we will sample the terrestrial insects to see whether they have gained significant aquatic Hg-signature.
Aquatic organisms such as sculpin, dace and stickleback which are known to consume allochthonous sources will also be sampled to identify terrestrial mercury-signauture.
This will involve the analyses of stable Hg isotopes, mercury concentrations, stable carbon and nitrogen isotopes.