Distribution of organic and inorganic mercury across the pelts of Canadian river otter (Lontra canadensis)

Abstract

Fur is a common biomarker of environmental mercury (Hg) exposure. Further, there are well-established relationships between total mercury (THg) in fur and organs. However, these models assumed that THg is uniformly distributed across the fur in a pelt. In this study, we assess the distribution of THg and methylmercury (MeHg) across the pelts of four river otters (Lontra canadensis) . THg concentrations were measured in the topcoat (n = 95) and undercoat fur (n = 95). MeHg was measured in a subset of these samples (n = 10). Patterns of THg and MeHg were explored using cluster analyses and ANOVAs. Significant differences existed between THg in topcoat and undercoat and between anatomical region (head/body/tail/legs) and fur regions (dorsal/ventral/furline). The cluster analysis showed significant THg clusters in undercoat fur and to a lesser extent topcoat fur. Further, the error rate for predicting internal THg is lowest in the forebody region of the topcoat, thus, making this the optimal region to sample for biomonitoring. Fur samples taken outside of this region could result in prediction error as high as 140% when estimating internal organ THg. The ratio of MeHg in THg in topcoat fur was measured at 95.7 ± 3.4% indicating THg concentrations can be used to assess MeHg exposure.

The Twilight Zone as a Major Foraging Habitat and Mercury Source for the Great White Shark

“…Total Hg (THg) is known to be predominantly in the MeHg form in the dermis and muscle of various shark species, ,− aquatic and marine mammal hair, − as well as in pelagic fish muscle and squid mantle. , THg was thus used as a proxy for MeHg concentrations in all the species studied here. Moreover, THg isotope ratios in sharks and seals analyzed in this work, or obtained in pelagic organisms from previous studies, , mainly reflect the isotopic signature of MeHg.…”

A synthetic review of terrestrial biological research from the Alberta oil sands region: 10 years of published literature

“…ICBM programs represent ongoing local‐scale contaminant monitoring opportunities, with Indigenous hunters and trappers in the OSR providing samples of semi‐aquatic mammals for toxicological analysis for mammal health monitoring (e.g., Thomas et al, 2021 ) and ongoing methodological developments in mammal toxicology (Eccles, Littlewood, et al, 2019 ; Eccles et al, 2020 ). Monitoring plant contaminants, specifically the deposition of contaminants onto food, medicinal, and culturally important plants, is also conducted within ICBM programs and there is extensive Traditional Knowledge on the topic, covered in the ICBM review in this special series (Beausoleil et al, 2021 ).…”

Innovations that changed Mammalogy: museum study skins

“…For example, stable isotopes have been used to better understand the migratory behavior of the poorly known silver-haired bat (Lasionycteris noctivagans) across eastern North America (Fraser et al 2017). Mercury (Hg) pollution in the environment can now be traced through preserved hair samples (Solgi et al 2013;Eccles et al 2019). The fur of Peruvian bats found well downstream from mining operations where Hg is used in extracting gold contains significant concentrations of Hg.…”