Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

First Advisor

Charles D. Dieter


Currently, river otters (Lontra canadensis) occupy half their historical range, which extends throughout Canada and northern parts of the United States including the Great Lakes, the northeast, and the northwest regions. The river otter is a statethreatened species in South Dakota. I determined the current status and distribution of the river otter population and whether adequate habitat was available for reintroducing river otters in South Dakota. Rivers were selected by buffering specific features, such as stream size ( orders three to seven), water gradient, and water permanence, using the South Dakota Gap Analysis Project stream reach and watershed data. Vegetation transect sampling was conducted and a water sample was collected at each study site. Once information was obtained, rivers were rated ( one to five, where river otter suitability increases with increased values) according to river otter habitat requirements and based on stream characteristics, watershed features, water quality, prey availability, and other factors ( e.g., private or public ownership and stream accessibility). No remnant river otter population was found in South Dakota. Eighty-nine percent of river otter sightings were observed in eastern South Dakota. River otter sightings were more likely in eastern South Dakota due to the river otter reintroduction efforts by the Flandreau Santee Sioux Tribe. Percent canopy cover of riparian vegetation ranged from Oto 29. Percent cover of graminoid ranged from 1 1 to 40, forbs ranged from 1 6 to 40, shrubs ranged from 3 to 24, and other (e. g., litter) ranged from Oto 26. Secchi depth ranged from 0.01 m to 0.9 m, dissolved oxygen ranged from 5 ppm to 1 1 .0 ppm, alkalinity (methyl-orange) ranged from 1 40 mg/I to 740 mg/1, and pH ranged from 7.5 to 8. 5. Phosphorus (orthophosphate) ranged from 0. 7 mg/1 to 6.3 mg/1, nitrogen (nitrate-nitrogen) ranged from 0.01 mg/I to 0.26 mg/1, and temperature ranged from 18 C to 29 C. Important prey species include fish, especially species within the Ictaluridae (catfish and bullheads) and Catostomidae (suckers) families. Rivers with high ratings had better habitat, higher water quality, and greater prey availability than rivers with low ratings. The five highest rated river systems in South Dakota were the Bad River (75), Big Sioux River (74), James River (72), North Fork of the Whetstone River (72), and Little White River (69). After establishing that areas with adequate river otter habitat were available in South Dakota, a river otter reintroduction protocol was developed. The protocol included river otter release procedures, estimation of reintroduction expenses, and consideration of logistical problems.

Library of Congress Subject Headings

North American river otter -- Reintroduction -- South Dakota.


South Dakota State University



Rights Statement

In Copyright