Hepatic mercury, cadmium, and lead in mink and otter from New York State: monitoring environmental contamination

Abstract

Many non-linear processes link atmospheric emissions to the bioavailability of metals; consequently, the monitoring of metals in ecosystem components is required to model their ecodynamics. American mink (Neovison vison) and river otter (Lontra canadensis) have the potential to serve as an upper-level-consumer component in monitoring metals bioavailability. However, the relationship of bioaccumulated metals to various environmental factors has not been explored nor have the effects of demographic factors been resolved. To address these limitations, mink and otter, collected throughout New York State during 1998-2002, were analyzed for hepatic concentrations of total mercury (Hg), cadmium (Cd), and lead (Pb). Relationships were investigated between metals concentrations and landscape-level factors (physiographic zone, hydrologic unit, and elevation) and demographic factors (gender and age). Considerable variation in Hg and Cd concentrations was observed relative to both physiographic zone and hydrologic unit for both species. In contrast with Hg, Cd concentration increased predictably with increasing elevation. Mercury concentrations were greater, but for Cd less, in otter than mink. Lead concentrations showed little landscape heterogeneity and were independent of elevation. Age-related bioaccumulation was evident for Hg and Cd, but not for Pb, in both species. Mercury and Cd concentrations were greater in female than male mink; however, Pb concentrations were greater in males than females. Inverse relationships of relative growth (weight/length) to metals concentrations explained gender differences in Hg and Cd in mink. For otter, no gender-related differences in metals concentrations were apparent. The suitability of mink and otter for monitoring programs is discussed.

The use of chemical markers for the identification of farm escapees in feral mink populations

“…However, such differences have been recorded in the case of mercury in some studies: concentrations of Hg were greater in female than male mink tissues (Gamberg et al 2005) or just in livers (Yates et al 2005). Mayack (2012) recorded higher concentrations of Hg and Cd in female mink and explained this finding by gender differences in relative growth. On the other hand, it was found that lead concentrations were higher in male mink (Mayack 2012).…”

“…Mayack (2012) recorded higher concentrations of Hg and Cd in female mink and explained this finding by gender differences in relative growth. On the other hand, it was found that lead concentrations were higher in male mink (Mayack 2012). The feeding habits of mink are also gender related (Birks and Dunstone 1985), and result mostly from the well pronounced sex-related size dimorphism.…”

“…Most have examined the concentration of Hg and other elements such as Cd, Pb and Se (e.g. Fortin et al 2001; Gamberg et al 2005; Yates et al 2005; Lake et al 2007; Martin et al 2011; Mayack 2012), and just a few have analyzed a broader spectrum of trace elements (Stejskal et al 1989; Halbrook et al 1996). The level of mercury in mink tissues is of particular concern, since this heavy metal is highly toxic and may become biomagnified in high-level predators.…”

“…This fact is related to the high mortality rate of feral mink, whereby individuals of over 1 year old comprise only a small fraction of the population. Furthermore, the initial mercury concentrations in mink may be high, possibly due to maternal transfer, and the limited relative increases in Hg with age suggests that the hepatic mercury burden is, to a large extent, established by Hg exposure during early development (Mayack 2012). …”

Spatial patterns and temporal trends of heavy metal concentrations in moss and surface soil specimens collected in Norway between 1990 and 2010

“…Environmental exposure to pollutants such as heavy metals (HM) can impact structures and functions being relevant for ecosystem integrity and human health [1][2][3][4][5][6]. To avoid such impacts due to atmospheric HM deposition, the Protocol on Heavy Metals of the Convention on Long-Range Transboundary Air Pollution, adopted in 1998, targets three particularly harmful metals: cadmium (Cd), lead (Pb) and mercury (Hg).…”