Landowners Key To Potlatch River Steelhead Study
 

By Nathan Brindza - Idaho Department of Fish and Game

Spring is right around the corner and the Idaho Department of Fish and Game (IDFG) will once again be studying steelhead of the Potlatch River drainage.

IDFG will install two adult steelhead weirs, one on Little Bear Creek and one on Big Bear Creek, to count the number of adults returning to the these streams. The weirs resemble a large V-shaped fence that extends across the stream. The weirs funnel adult steelhead into holding pens, where each is counted, measured, and marked before being released upstream.

A screw trap in Big Bear Creek near Kendrick High School functions the same way but will estimate the number of smolts leaving the creek and provide an opportunity for local students to observe science in action. Later in the spring, dedicated college students hired for the summer will be awakening at 3 a.m. to survey fish populations throughout Little and Big Bear Creeks, Corral Creek, and Cedar Creek.

Although surveying the steelhead population is one aspect of the project, habitat improvements are the main efforts in the Potlatch River to improve steelhead numbers. It is expected that through habitat improvement, the survival of juvenile steelhead can be improved and result in more steelhead in the future.

Landowners throughout the Potlatch River watershed can help, and without them, this project would not be possible. Many landowners will be contacted by IDFG as the field season approaches for permission to access the stream. Allowing permission greatly enhances our ability to determine where fish are, how many there are, and what can be done in the future to increase populations.

The information gathered in the population surveys will add to the information already known about steelhead in the drainage. By tracking the numbers of steelhead and their survival, we can determine what effect the habitat improvement efforts are having on the fish and which types of habitat improvements work best. This information will allow interested landowners, individuals, and groups to better manage the land in the Potlatch River to provide for both themselves and the fish.

The Potlatch River population of wild steelhead is listed as threatened under the Endangered Species act and is part of the Snake River Basin Steelhead distinct population segment (DPS). The Snake River steelhead DPS is a group of steelhead that includes all naturally spawned populations of steelhead and their progeny in streams in the Snake River Basin of southeast Washington, northeast Oregon, and Idaho.

IDFG has been conducting studies of the fish populations in the Potlatch River for several years. Last year, the Idaho Office of Species Conservation awarded IDFG a contract to study steelhead in the Lower Potlatch River in more detail. The result was an extensive effort to count the number of adults returning to Bear Creek, the number of smolts leaving Bear Creek, study steelhead survival, and estimate steelhead numbers in Big and Little Bear Creeks, Corral, and Cedar Creek.

Funding for this detailed study came through the Pacific Coast Salmon Recovery Fund, a funding opportunity provided by the National Oceanic and Atmospheric Administration Fisheries Service.

Results from last year are very exciting. An estimated 266 adults returned to Big and Little Bear creeks during the spring of 2005. This is a considerably higher number of adults than expected. These adults are known to have spawned as high as the city of Troy in the West Fork of Little Bear Creek. Anglers should keep in mind that the Potlatch River and its tributaries are closed to steelhead fishing. Any steelhead caught while fishing in the Potlatch River need to be released immediately.

Numbers of juvenile fish were also surprising. Initial estimates indicate approximately 14,000 juvenile steelhead left Big Bear Creek this past spring. Passive integrated transponder (PIT) tags were place in over 2,000 of these fish to estimate survival during migration. PIT tags allow us to detect individual fish as they pass through the dams on the Snake and Columbia River system. Survival of these fish to Lower Granite dam was approximately 65 percent. Juvenile fish were also tagged during the summer in Little Bear, Big Bear, Corral, and Cedar Creeks. These fish will be detected at the dams in the spring of 2006.

The numbers of fish counted in these surveys, now and in the future will be used to evaluate habitat improvement efforts being undertaken by many interested individuals and groups in the Potlatch River area. It is expected that fish survival and numbers can be increased by improving the stream conditions in the Potlatch River and its tributaries.

These efforts will take many years to produce the desired outcomes of decreasing stream temperatures, decreasing winter and spring peak flows, and increasing summer flow. However the information we gather now about fish will help to improve efforts at habitat repair in the future.

Again, landowners are the key to this project. Allowing access and providing information such as easy access points to the water, historic knowledge of fish, historic land management practices and other tidbits of information can help greatly and provide surprising insights into the ecology of the river. Please do not hesitate to share information with IDFG, as it might be more important than you think.

For more detailed information on the project contact Nathan Brindza, regional fisheries biologist at (208)799-5010 or nbrindza@idfg.idaho.gov.

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