Occupancy rates of river otters (Lontra canadensis) in the St. Louis River Area of Concern

IUCN/SSC Otter Specialist Group Bulletin
By: , and 

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Abstract

The St. Louis River Area of Concern (AOC), an estuarine system along the northeastern Minnesota-Wisconsin border, experienced significant ecological disturbances and degradation from unregulated industrial development during the 19th and 20th centuries. Recent restoration and remediation efforts in the AOC have led to substantial improvements in water quality, habitat, and fisheries populations. However, the status of wildlife populations following restoration efforts in the AOC remain largely unknown. We used remote cameras to estimate occupancy rates of river otters Lontra canadensis in the AOC and at two reference areas that had not been subjected to historical degradation. Because river otters occupy a high trophic level within these systems, we hypothesized that they would be an effective indicator species of overall habitat quality and recovery. Using data collected from June 2015 to February 2016, we developed single-season occupancy models for both summer and winter seasons. We found no differences in occupancy between the AOC and the reference sites, suggesting that river otter populations within the AOC were comparable to those in unaffected areas.  Our results indicate that habitat restoration and remediation efforts in the St. Louis River estuary have been successful in promoting healthy wildlife populations.

Suggested Citation

Evans, B.E., Tucker, M.C., Van Deelen, T.R., and Crimmins, S.M., 2026, Occupancy rates of river otters (Lontra canadensis) in the St. Louis River Area of Concern: IUCN/SSC Otter Specialist Group Bulletin, v. 43, no. 1, p. 24-34.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Occupancy rates of river otters (Lontra canadensis) in the St. Louis River Area of Concern
Series title IUCN/SSC Otter Specialist Group Bulletin
Volume 43
Issue 1
Year Published 2026
Language English
Publisher IUCN/SSC Otter Specialist Group
Contributing office(s) Coop Res Unit Seattle
Description 11 p.
First page 24
Last page 34
Country United States
State Minnesota, Wisconsin
Other Geospatial Boulder Lake, St. Croix River, St. Louis River Area of Concern
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