Heterogeneous detection probabilities for imperiled Missouri River fishes: implications for large-river monitoring programs

Authors

Joshua T. Schloesser, Kansas Cooperative Fish and Wildlife Research Unit, Division of Biology, Kansas State University & Present address: U.S. Fish and Wildlife Service, Ashland Fish and Wildlife Conservation OfficeFollow
Craig P. Paukert, U.S. Geological Survey, Kansas Cooperative Fish and Wildlife Research Unit, Division of Biology, Kansas State University & Present address: U.S. Geological Survey, Missouri Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife Sciences, University of Missouri
Wyatt J. Doyle, U.S. Fish and Wildlife Service, Columbia Fish and Wildlife Conservation Office
Tracy D. Hill, U.S. Fish and Wildlife Service, Columbia Fish and Wildlife Conservation Office
Kirk D. Steffensen, Nebraska Game and Parks Commission
Vince H. Travnichek, Missouri Department of Conservation

Date of this Version

3-22-2012

Citation

Vol. 16: 211–224, 2012

Comments

U.S. Government Work.

Abstract

Occupancy modeling was used to determine (1) if detection probabilities (p) for 7 regionally imperiled Missouri River fishes (Scaphirhynchus albus, Scaphirhynchus platorynchus, Cycleptus elongatus, Sander canadensis, Macrhybopsis aestivalis, Macrhybopsis gelida, and Macrhybopsis meeki) differed among gear types (i.e. stationary gill nets, drifted trammel nets, and otter trawls), and (2) how detection probabilities were affected by habitat (i.e. pool, bar, and open water), longitudinal position (five 189 to 367 rkm long segments), sampling year (2003 to 2006), and season (July 1 to October 30 and October 31 to June 30). Adult, large-bodied fishes were best detected with gill nets (p: 0.02–0.74), but most juvenile large-bodied and all small-bodied species were best detected with otter trawls (p: 0.02–0.58). Trammel nets may be a redundant sampling gear for imperiled fishes in the lower Missouri River because most species had greater detection probabilities with gill nets or otter trawls. Detection probabilities varied with river segment for S. platorynchus, C. elongatus, and all small-bodied fishes, suggesting that changes in habitat influenced gear efficiency or abundance changes among river segments. Detection probabilities varied by habitat for adult S. albus and S. canadensis, year for juvenile S. albus, C. elongatus, and S. canadensis, and season for adult S. albus. Concentrating sampling effort on gears with the greatest detection probabilities may increase species detections to better monitor a population’s response to environmental change and the effects of management actions on large-river fishes.