| methylmercury exposure associated with reduced productivity in common loons. | methylmercury can impair the reproduction of fish-eating wildlife. we measured lake ph, mercury (hg) concentrations in small fish, blood hg levels in adult male, female and juvenile common loons, and loon productivity from 120 lakes in wisconsin, usa and new brunswick and nova scotia, canada (maritimes). mean lake ph was higher in wisconsin than in the maritimes. body masses of adult loons and hg concentrations in the blood of loons and in small fish were greater in the maritimes. hg levels in f ... | 2008 | 18038272 |
| bioaccumulation patterns and temporal trends of mercury exposure in wisconsin common loons. | a long term field study was initiated by the wisconsin department of natural resources in 1992 to elucidate patterns of common loon (gavia immer) mercury (hg) exposure. analysis of loon blood and feather samples collected from recaptured adult loons in wisconsin 1992-2000 found evidence of a decline in overall body burdens of mercury in common loons for this region. the interval between sampling individual loons spanned 2-8 years, a sufficient length of time to observe a change in tissue hg conc ... | 2013 | 12739859 |
| bi-phasic trends in mercury concentrations in blood of wisconsin common loons during 1992-2010. | we assessed the ecological risk of mercury (hg) in aquatic systems by monitoring common loon (gavia immer) population dynamics and blood hg concentrations. we report temporal trends in blood hg concentrations based on 334 samples collected from adults recaptured in subsequent years (resampled 2-9 times) and from 421 blood samples of chicks collected at lakes resampled 2-8 times 1992-2010. temporal trends were identified with generalized additive mixed effects models and mixed effects models to a ... | 2011 | 21809120 |
| mercury and other element exposure in tree swallows nesting at low ph and neutral ph lakes in northern wisconsin usa. | the primary objective of this study was to determine whether tree swallows (tachycineta bicolor) demonstrate similar responses to lake ph and mercury (hg) contamination in northern wisconsin as do common loons (gavia immer). similar to common loons, hg concentrations in the blood of tree swallow nestlings were higher, hg concentrations in eggs tended to be higher, and egg size tended to be smaller at low (<6.2) ph lakes. in contrast to common loons, tree swallow nestling production was not lower ... | 2012 | 22325433 |
| influence of in ovo mercury exposure, lake acidity, and other factors on common loon egg and chick quality in wisconsin. | a field study was conducted in wisconsin (usa) to characterize in ovo mercury (hg) exposure in common loons (gavia immer). total hg mass fractions ranged from 0.17 µg/g to 1.23 µg/g wet weight in eggs collected from nests on lakes representing a wide range of ph (5.0-8.1) and were modeled as a function of maternal loon hg exposure and egg laying order. blood total hg mass fractions in a sample of loon chicks ranged from 0.84 µg/g to 3.86 µg/g wet weight at hatch. factors other than mercury expos ... | 2015 | 26096773 |
| mercury in swamp sparrows (melospiza georgiana) from wetland habitats in wisconsin. | wetlands play a major role in the export of methylmercury (mehg) to a watershed. the large contribution of wetlands to watersheds in northern wisconsin, coupled with the acidic environment of this area, makes these habitats especially vulnerable to mercury (hg) accumulation by biota. the purpose of this study was to compare hg accumulation between northern wisconsin wetlands and southern wisconsin wetlands using the swamp sparrow (melospiza georgiana) as a representative species. the swamp sparr ... | 2011 | 21755351 |