The decline of mink in Georgia, North Carolina, and South Carolina: The role of contaminants

Abstract

Since the 1960s, mink (Mustela vision) populations in Georgia, North Carolina, and South Carolina have declined, especially in the coastal plain. A prior study suggested that the decline may stem from environmental contaminants. Based on water quality data from each state, we identified 17 substances potentially related to the decline: aldrin, dieldrin, endrin, DDD, DDE, DDT, PCBs, chlordane, alpha-BHC, toxaphene, dibenzofuran, copper, chromium, cadmium, lead, arsenic, and mercury. Mink livers were analyzed for PCB and organochlorine pesticides, and kidneys and femurs were analyzed for metals. Reference sample concentrations from piedmont, mountain, and foothill locations were compared to state coastal plain totals and counties. PCBs for Georgia, dieldrin for South Carolina, and endrin and aldrin for North Carolina were significantly higher than the piedmont reference group. Liver PCB concentrations were higher than those known to cause mink reproductive dysfunction. Mercury concentrations were significantly higher in coastal plain mink from all three states and were in the range of those known to cause impacts to reproduction, growth, and behavior to wild mink. It is unknown what concentrations of cyclodienes cause reduced reproduction or other physiological effects in mink, but the levels reported here probably indicate background concentrations that do not contribute to the decline.

Environmental contaminants in freshwater fish and their risk to piscivorous wildlife based on a national monitoring program

“…NEHCs for both mink and bald eagle were exceeded at Sites 23,24,67,76,111,320,324,327,and 330. Elevated PCB concentrations have been previously documented in water and biota near Site 327 (USFWS 1996;Schmitt et al 1999;Zappia 2002), and PCBs were identified as a potential cause of reproductive dysfunction in mink from the coastal plain of Georgia, South Carolina, and North Carolina (Osowski et al 1995). We are not aware of contaminant studies evaluating the risk of total PCBs to piscivorous wildlife in the Mississippi River Basin downstream from Memphis (Site 76) or the Ohio River Valley (Sites 23, 24, and 67).…”

“…Other studies also have reported that mercury concentrations in these regions represent a risk to avian and mammalian wildlife (Halbrook et al 1994;Osowski et al 1995;Ambrose et al 2000;Adair et al 2003). Mercury has been suspected to cause reproductive effects, organ toxicity, and mortality in prothonotary warbler (Protonotaria citrea), mink, and river otter throughout the southeastern United States (Halbrook et al 1994;Osowski et al 1995;Adair et al 2003). Ambrose et al (2000) reported that mercury concentrations in peregrine falcon (Falco peregrinus anatum) breeding in the Yukon River Basin were associated with lower nest success.…”

“…This relationship may explain the high fish concentrations and associated risk of mercury in the southeastern United States and Yukon River Basin, where mercury methylation rates are known to be high (Brumbaugh et al 2001). Other studies also have reported that mercury concentrations in these regions represent a risk to avian and mammalian wildlife (Halbrook et al 1994;Osowski et al 1995;Ambrose et al 2000;Adair et al 2003). Mercury has been suspected to cause reproductive effects, organ toxicity, and mortality in prothonotary warbler (Protonotaria citrea), mink, and river otter throughout the southeastern United States (Halbrook et al 1994;Osowski et al 1995;Adair et al 2003).…”

Aldrin and dieldrin: a review of research on their production, environmental deposition and fate, bioaccumulation, toxicology, and epidemiology in the United States.

“…Dieldrin levels were highest among mammals in the coastal areas of North and South Carolina. This could contribute to the decline of the mink population (75). A study conducted from 1991 to 1995 of mink in Canada also tracked longrange atmospheric transport of dieldrin and reported concentration levels that may affect future population levels (76).…”

Evaluation of Pesticide Toxicity and Chemical Compounds Revealed in Soils of Sikasso and Segou (Mali)

“…Organochlorine pesticides have varying effects on endocrine functions, fertility and the immune system of birds and mammals [13]. Some work have confirmed the decrease in reproduction, growth and increased risk of hyperthyroidism in mammals by pesticides [14] [15]. Many experiments corroborate the decline in fertility, increased risk of mis-carriage, premature deliveries, birth defects, cancer, damage to DNA and accumulation of pesticides in human's milk [16]- [19].…”