Results of Wind River Sauger Study
Former University of Wyoming graduate student Craig Amadio and his advisor Dr. Wayne Hubert of the University of Wyoming Cooperative Fish and Wildlife Research Unit recently released the results of their Wind River watershed sauger study. Sauger (Sander canadensis - a member of the perch family) look much like a camouflaged walleye, and are one of the native fishes of the Wind River watershed. Although sauger were once found in most of the major river basins in Wyoming including the North Platte, Powder, Tongue, and Wind/Bighorn river drainages), they are now rare in the Powder and Tongue rivers and have been extirpated from the North Platte. The Wind River above Boysen Dam supports one of the few remaining genetically-pure sauger populations in the Western U.S., yet very little was known about Wind River sauger before Amadio’s study.
Sauger sampling took place during the summer and fall of 2002 using raft-mounted electrofishing equipment and standard analysis of stream chemistry and habitat features. The objective of the research was to understand the distribution, abundance, population structure, and habitat use of sauger in the Wind River watershed and to use this new data to identify conservation and management implications.
Amadio and his team collected a total of 1,258 sauger from 105 miles of the Wind, Little Wind, Popo Agie, and Little Popo Agie rivers below an elevation of 5,180 feet. Sauger ranged from 13 to 25 inches and were the most abundant predator fish in the drainage. The sauger population in the Wind River watershed is estimated to be about 4,300 fish, with the highest sauger densities found in the lower portions of the Little Wind and Popo Agie rivers. Sauger tend to prefer deep, slow pools with warm, turbid, nutrient rich water.
Sauger are highly migratory, and they are strongly affected by migratory barriers associated with water development. The sauger in the Wind River watershed are no exception, as the upstream distribution of sauger in the Little Wind and Little Popo Agie rivers is controlled by the location of major irrigation diversion structures (Sub-Agency Diversion Dam, and Lyon’s Diversion Dam) which form barriers to upstream sauger movement. Amadio and Hubert’s research is an important first step in better understanding the sauger in the Wind River watershed so they can be managed to ensure that there will always be a thriving sauger population. Amadio concluded from his research that "Future conservation and management of this population will involve preserving natural fluvial processes to maintain water temperatures and physical habitat important to sauger, as well as assuring that barriers to movement are not created that would reduce the upstream boundaries of the population."
In addition, Amadio notes "Interagency cooperation between fisheries and water managers will be essential to effectively manage sauger in the Wind River basin." As both fisheries and water management involve multiple tribal, federal, and state agencies, interagency cooperation is also vital to sauger conservation. With greater scientific understanding and improved communication and cooperation between management agencies, this important population of native fish can be protected.
For more information, contact Craig Amadio at Craig.Amadio@wgf.state.wy.us, or Dr. Wayne Hubert at whubert@uwyo.edu