Seasonal Movement Patterns, Habitat Use, and Home Range of Flathead Catfish in the Lower St. Joseph River, Michigan

Abstract

Few studies have examined the seasonal movement patterns, habitat use, and home range of flathead catfish Pylodictis olivaris in lotic systems throughout the northern United States. We used ultrasonic telemetry on 39 flathead catfish (range, 430–1,132 mm total length) in the lower St. Joseph River, Michigan, to increase our understanding of these behaviors in northern populations of flathead catfish and to provide important information for the development of appropriate management strategies in this system. Transmitters were surgically implanted into the peritoneal cavity of selected individuals captured by means of low-voltage AC electrofishing during 2002 and 2003. Habitat use of flathead catfish was dominated by large woody debris and riprap at water depths less than 3 m during all seasons except winter, when fish utilized main-channel pool habitats associated with coarse substrates at water depths greater than 4 m. Flow rates at fish locations were not significantly different among seasons (range, 0.1–0.7 m/s). The mean seasonal movement distance and home range of flathead catfish were greatest during spring (1,045 and 1,513 m, respectively) and fall (1,146 and 1,296 m, respectively), when fish transitioned between summer and winter habitats, while movement distance and home range during summer months averaged 218 and 596 m, respectively. No movement was observed during the winter season. Our study results indicate that seasonal differences exist in the movement patterns, habitat use, and home range of flathead catfish in the lower St. Joseph River and that the availability of structure and main-channel pool habitats are important considerations in the management of this species.