Quantifying Hg within ectomycorrhizal fruiting bodies, from emergence to senescence.

Ectomycorrhizal fruiting bodies (basidiomata) collected from forested areas in southwestern New Brunswick were analyzed for total mercury, sulphur, nitrogen, and carbon concentrations (THg, TS, TN, and TC, respectively). This analysis was done for caps and stalks and by development stage (emergent, mature, senescent) across 27 species associated with five classes, eight families, and 13 genera. Across the species, THg correlated positively with TN and TS, thereby implying N as well as S mitigated transfer of Hg from the mycelia into the basidiomata, with THg ranging from 3 to 10 457 ppb.

Factors affecting water strider (Hemiptera: Gerridae) mercury concentrations in lotic systems.

Water striders (Hemiptera: Gerridae) have been considered as a potential sentinel for mercury (Hg) contamination of freshwater ecosystems, yet little is known about factors that control Hg concentrations in this invertebrate. Striders were collected from 80 streams and rivers in New Brunswick, Canada, in August and September of 2004 through 2007 to assess the influence of factors such as diet, water chemistry, and proximity to point sources on Hg concentrations in this organism. Higher than average Hg concentrations were observed in the southwest and Grand Lake regions of the province, the latter being the location of a coal-fired power plant that is a source of Hg (approximately 100 kg annually), with elevated Hg concentrations in the lichen Old Man's Beard (Usnea spp.

Water striders (family Gerridae): mercury sentinels in small freshwater ecosystems.

To circumvent some of the previous limitations associated with contaminant-monitoring programs, we tested the suitability of the water strider (Hemiptera: Gerridae) as a mercury sentinel by comparing total mercury concentrations in water striders and brook trout (Salvelinus fontinalis) from a variety of stream sites in New Brunswick, Canada. There was a strong association between the two variables across sites (r(2)=0.81, P<0.