Project Report: Effects of Mercury on Aquatic Furbearers

Issue/Problem Statement

Elevated levels of mercury have been found in fish and fish-eating birds in western Nova Scotia and elsewhere in Northeastern North America. An assessment of levels and effects on other fish-eating carnivores (mink, otter) is required.

Objective

To assess levels and effects of mercury in aquatic carnivores and investigate sources of this contamination in Nova Scotia.

Methods

Collect tissue samples from provincial otter harvest carcass collection and/or live capture specimens and analyze mercury levels. Collect tissue samples from mink carcasses provided by fur harvesters. Relate results to such variables as age, sex, location of kill, food habits, etc.

Partners

Nova Scotia Department of Lands and Forestry Regional Services and Canadian Wildlife Service, US Fish & Wildlife Service.

Project Dates and Duration

Collections from provincial harvest November 1-February 28. Carcass processing and tissue analysis in succeeding months. On-going.

Progress to Date

Limited collection from one trapper in western Nova Scotia 1995-96. 1996/97 harvest collection completed and samples submitted for analysis. Analysis of 1995/96 samples complete. 1997/98 collection completed.

Reporting

Field carcass data sheets to be forwarded to Wildlife Division with specimens. Data will be maintained in paper and/or electronic format as appropriate. Reports will be in various formats and venues by CWS, NSDNR, and/or US Fish & Wildlife Service as appropriate (e.g. scientific papers; popular reports in media; Nature's Resources; Trappers Newsletter, etc.).

Reports on this topic can be found in:

  • NS Trappers Newsletter, Number 40, 2004
  • NS Trappers Newsletter, Number 41, 2005
  • NS Trappers Newsletter, Number 42, 2006

    Articles:
  • Spencer, S.H., Shutler, D., O'Brien M.S. "Correlators of Mercury in Female River Otters from Nova Scotia, Canada". Environ. Toxicol. and Chem. 30, 2011: 1-6.
  • Management Recommendations

    Continue project as the results are important not only to the management of furbearer species, but to our better general understanding of environmental mercury contamination in all wildlife.

    Final Report:

    Unknown. Preliminary results have been examined and reported. Further research is on-going and proposed.

    Completion Dates:

    Unknown; project may take 2-3 years.