Report 162

162. MacDonald C., B Elkin and A. Gunn. 2005. Analysis of the Elemental Composition of Tissues and Faecal Ash in a Moose ( Alces Alces) Exposed to Tailings at the Abandoned Colomac Gold Mines, NWT.  39 pp

ABSTRACT

A moose Alces alces jumped the fence bounding the tailings area of the Colomac mine site. The moose had been within the fenced tailings area for about 2 weeks. Concerns about possible contamination of the moose led to the moose being shot by a team comprised of a Tłi Cho elder and RWED personnel.  We carried out a necropsy and sampled the moose tissue to determine the degree of contamination.  This information would support other projects associated with exposure and ecological risk to Colomac wildlife from contaminants.  Approximately 35 tissues, including gut contents and faecal material were collected and analyzed for metals by ICP/MS.  The concentrations of individual elements varied markedly between individual tissues, and along the gut.  Cyanide was below detection in most tissues but increased to about 5 mg·kg^-1 in the omasum contents and caecum. Arsenic concentration was low in most tissues but the concentration was slightly higher in the tongue and faecal material.  The higher levels of many elements in the hind gut and faecal material is probably due to the low rates of uptake in the gut, which results in increasing concentration as material moves through the digestive tract. Ash content of the gut contents was relatively high at lower ash temperatures, which may reflect the type of organic material in moose browse.  Principal components analysis of the metal residues in the faecal ash fraction showed some similarity to Colomac tailings, while the pattern of metals in the gut contents resembled that of Paddle Lake caribou faecal material, probably due to high sodium content. When compared to Colomac caribou faecal pellets, the moose faecal pellets showed higher proportions of zinc, strontium and magnesium which could reflect the different metal content in insoluble material on moose browse. Blood and tissue levels of cyanide in this moose reflect oral exposure and uptake of environmental cyanide associated with the Colomac tailings pond, and highlight the potential environmental risk of acute cyanide toxicity.   While the animal did not exhibit clinical signs consistent with cyanide toxicity prior to death or any histological evidence of tissue damage, blood levels were within the toxic range reported for domestic livestock.