Population Characteristics and Habitat Selection of Walleye in the Big Sioux River, South Dakota

Walleye were collected from the middle Big Siou.x River to assess the status of the population and detennine use of the habitat during winter. Eleven of 246 (4.5%) tagged walleye were caught by anglers over 250 km of the upper river. Analysis of scales from 322 fish yielded mean length (mm) at each age as follows: age 1, 215; age 2. 370; age 3, 46 I: age 4, 519: age 5, 571; age 6, 617; and age 7, 675. The gro\\1h rate was faster then that in other north central rivers. Relative weights were between 95 and 105 for all but one length category. Electrofishing catch-per-effort was comparable to several other rivers at 2.2 fish/hr for all seasons combined (4.3, spring; 1.7, summer, 2.1, fall). Trap net catch-per-effort was 0.065 fish/hr. Year class strength varied 14 fold over six years and was positively related to river discharge (r=0.86). Water temperature fluctuation in March and April was too erratic in 1992 for optimum egg development. The bottom area covered by suitable spawning substrate was 9.5% in 1993 and 14% in 1994, which is less than the 20% suggested as minimally needed to sustain the population. During the fall, most walleye were located in current velocities of about 0.23 mis, at depths of 125-200 cm, and over sandy or mixed sand-silt or sand-gravel substrates. Most fish were not near woody debris, tributary confluences, or bridge crossings, but used these velocity refuges when flow increased (r=0.99). When under ice that was 20-60 cm thick, walleye selected currents of 0.08-0. I 8 mis in higher frequencies than the availability of these current speeds (Chi-square> 28, P<0.00 I). Walleye were located in depths of 100-150 cm 94% of the time under ice. Fish were over sand during the winter and remained in main-channel pools where water temperatures dropped to -0.8°C. Dissolved oxygen concentrations at walleye locations were > 6.4 mg1. Average daily movement varied greatly among individuals and ranged from zero to 679 m/day Dams may block passage. The status of the walleye population is acceptable, but nonpoint source pollution and the migratory behavior of the species require basin-wide management approaches.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

1996

Author dc:creator

• Fisher, Christopher J.

Contributors dc:contributor

• Charles R. Berry

• south dakota
• big sioux river
• habitat
• ecology
• walleye
• population
• Natural Resources and Conservation

Statement dc:rights

• Copyright © 1996 Christopher Fisher

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/353

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1353