Cause‐effect linkages between chemicals and populations of mink(mustela vison)and otter(lutra canadensis)in the great lakes basin

Abstract

Following outbreaks of reproductive failure in commercial ranching operations, laboratory experiments showed that mink are extremely sensitive to organochlorine chemicals, particularly PCBs and dioxins. The purpose of this paper is to test the hypothesis that, since wild mink are exposed to these compounds through consumption of Great Lakes fish, they might exhibit reproductive dysfunction and population declines. The otter, another piscivorous animal, should show the same effects. The available information is reviewed according to five epidemiological criteria. Harvest data are presented as a surrogate for the population status of mink and otters in certain locations around the Great Lakes. Data from Ohio show that the mink harvest between 1982 and 1987 from contaminated counties bordering Lake Erie was consistently lower (380 animals per year) than those from counties removed from Lake Erie (850 animals per year), suggesting an effect of chemicals on the status of mink populations. Preliminary studies from Ontario also suggest that mink harvest is lower in potentially "high PCB exposure areas" compared with lower exposure areas. Evidence is also presented on the harvest data for otters taken from four New York State counties adjacent to Lake Ontario and the St. Lawrence River. The harvest data from these four counties show that between 1960 and early 1970 otter harvest remained stable but has since increased. Increased harvest is consistent with improved water quality in Lake Ontario during the past 15 yr. Data relating to strength of association between chemicals and populations of mink and otter are weak and need to be further analyzed. The specificity of the effects of the chemicals on mink reproduction and mortality is well established from toxicological experiments, but there is poor resolution of the information on effects using field data. The strongest case for a causal relationship comes from consideration of the coherence criterion. In conclusion, before a causal link can be drawn between the status of mink and otter populations and exposure to organochlorine chemicals from the Great Lakes, a large amount of research and data analysis needs to be undertaken.

Contamination par les PCBs et les pesticides organochlorés des poissons du Grand-Duché de Luxembourg : incidence possible sur les populations de loutre (Lutra lutraL.)

“…comme très dangereuse. Une telle méthode est cependant sujette à la critique (Bleavins et al 1980, Wren 1991.…”

Merging Wildlife and Environmental Monitoring Approaches with Forensic Principles: Application of Unconventional and Non-Invasive Sampling in Eco- Pharmacovigilance

“…As top level piscivorous predators, osprey (Pandion haliaetus), otter (Lutra sp.) and mink are generally considered to be representative barometers of aquatic/semi-aquatic ecosystem health [10,[64][65][66][67][68][69][70][71]. Interestingly, the use of mink and otter as sentinels/bio-indicators or related sample types, as both pertain to factors such as contaminant body burden, have been called into question [72,73].…”

Risks and Management of Dioxins and Dioxin-like Compounds in Baltic Sea Fish: An Integrated Assessment

“…Generally an ecoepidemiological weight-of evidence approach is needed (Fox 1991, Mac and Edsall 1991, Wren 1991, Grasman and Fox 2001, p. 332-40, Suter et al 2002. Due to the many dimensions of generalization and the many factors in this inference (e.g.…”