Samples/data collected by joint University-community monitor team: 1) Fish (15-20 individuals/species, up to 4 food fish species/lake): a. Captured with gill nets and dissected for muscle tissue (frozen for Hg and stable isotope analysis) and ageing structures; b. Fishing locations determined by local fishers and elders. 2) Benthic Invertebrates and sediments (min. 3 samples/taxa at 5 sites/lake): a. Profundal (deep) and littoral (nearshore) invertebrates collected with Ekman dredges and kick nets; b. Samples coarsely sorted in the field, divided in half, and: i) preserved in ethanol for taxonomic identification; ii) frozen for stable isotope and total and methyl Hg analysis; c. Sediments collected with an Ekman dredge, frozen for Hg analysis. 3) Zooplankton (min. 3 sample/size fraction at 3 sites/lake): a. Collected with vertical tows, size-fractioned; b. Half of each size fraction preserved in ethanol for community composition analysis, other half frozen for stable isotope and total and methyl Hg analysis. 4) Water (min. 5 sites/lake – top and bottom): a. Filtered and unfiltered water samples collected from each lake, and from influent streams and wetlands. Ultra-trace sampling methods used for Hg. 5) Abiotic: a. Catchment size and slope, lake area and volume, % wetlands and hydrology in catchment, underlying geology determined using GIS and field-based techniques.