Influence of Saugeye on Black Crappie Populations in Two Northeastern South Dakota Impoundments

Saugeyes (purposeful hybrid between walleye Stizostedion vitreum and sauger S. canadense) were introduced into Lakes Richmond and Mina in Brown County, South Dakota. The objectives of this study were to 1) determine relative survival of advanced fingerling saugeyes stocked into Lakes Richmond and Mina, 2) determine changes in black crappie Pomoxis nigromaculatus populations that were potentially associated with the saugeye introductions in Lakes Richmond and Mina, and 3) determine food habits of saugeye in Lake Richmond. Saugeyes were stocked at a total length of 3 to 4 cm in 1992 and 1993; survival in both lakes was low. Fall sampling collected only 3 to 5 age-0 saugeyes per hour of night electrofishing at both lakes. Larger (i.e., 1 4-25 cm) saugeyes were stocked from 1 994 to 1 998, and survival was significantly (P≤0. 05) higher. During 1 994 to 1 998, fall catch of age-0 saugeyes were as high as 1 85 per hour of night electrofishing at Richmond Lake and 1 22 per hour at Mina Lake. The larger fingerlings clearly were more able to survive and establish a population in the face of predation by and competition with black crappies. Prior to the saugeye introduction program, Richmond Lake contained a high-density, slow-growing black crappie population. By the end of the study, black crappie growth rates had increased significantly (P≤0.05). Prior to the saugeye stocking program, a 20-cm black crappie typically added less than a 25-mm annual growth increment. By 1999, a 20-cm black crappie added an average increment of 70 mm. As a result, size structure increased significantly (P≤0. 05); prior to the saugeye introduction, few black crappies exceeded 25 cm, but such fish were common by 1998 and 1 999. The Mina Lake black crappie population had not historically existed at such a high density as the Richmond Lake population. However, black crappie growth still was significantly higher in 1 999 than in 1 992 at the initiation of this study. Size structure increased through 1 998, but then declined, perhaps due to natural fluctuations in black crappie recruitment. Saugeye food habits were monitored seasonally at Richmond Lake during 1998. Saugeyes in all length groups consumed age-0 black crappies during all sampling periods except early spring when age-0 fishes were not yet available. Larger (>20 cm) black crappies were not observed in saugeye stomachs during this study. Thus, saugeyes in Richmond Lake likely reduced abundance of small black crappies, decreasing intraspecific competition, and resulting in the increased growth rates for crappies.

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

2001

Author dc:creator

• Galinat, Gene F.

Contributors dc:contributor

• David W. Willis

• south dakota
• richmond lake
• mina lake
• black crappie
• saugeye
• fish populaitons
• habitat
• Natural Resources and Conservation

Statement dc:rights

• Copyright © 2001 Gene F. Galinat . All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/430

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1430