Monitoring Salmon Populations

A study is underway to learn more about juvenile salmon and steelhead recolonizing the White Salmon River basin. A rotary screw trap for fisheries research was installed on the lower river from March to May 2016. The fish trap was used by the U.S. Geological Survey and Mid-Columbia Fisheries Enhancement Group to monitor migrant juvenile salmon and steelhead. This work is part of broader assessment of recolonization of the White Salmon River by salmon and steelhead after the historic removal of Condit Dam.

 

White Salmon Screw Trap Map

White Salmon River smolt trap location, 2016.

Following strict fish safety protocols, scientists are also temporarily isolating small reaches of tributaries and the mainstem White Salmon to sample juvenile salmon with portable electrofishing equipment.

This is the first study since the removal of Condit Dam that is providing information on juvenile salmon and steelhead. Several of the species being studied are listed as Threatened under the Endangered Species Act, including lower Columbia Chinook salmon, lower Columbia coho salmon, Columbia River chum salmon, Mid-Columbia steelhead, and bull trout.

More than $37 million has been invested in restoring fish passage to the White Salmon River, and efforts are underway to learn about the results of that investment. The 2016 monitoring of juvenile salmon is funded by a grant from the Washington State Salmon Recovery Funding Board. This work is part of an effort by scientists from several agencies and the Yakama Nation to study the distribution and abundance of fish that are recolonizing the White Salmon River. For example, annual fall Chinook salmon and steelhead spawning surveys have been conducted in the river by the Washington Department of Fish & Wildlife and the Yakama Nation to estimate adult fish populations.

The National Marine Fisheries Service’s 2013 Endangered Species Act Recovery Plan sets population abundance goals for many of the species. The Recovery Plan calls for a monitoring program as a key action toward successful implementation of the plan. Key questions, outlined in the monitoring section of the Recovery Plan are: what is the source and abundance of colonizing salmon and steelhead, what is the productivity of those fish, and are they producing viable offspring to support population persistence?

Prior to the removal of Condit Dam, scientists from the US Geological Survey studied fish populations in the White Salmon River as well as Rattlesnake and Buck Creeks. With new data, scientists will be able to begin comparing changes in fish populations in the river.

In the past, a group of scientists and managers analyzed various options for salmonid recovery / re-introduction to the White Salmon River for each migratory fish species that had been extirpated from the habitat upstream of Condit Dam. Based on the recommendations of this group, each species was allowed to naturally recolonize the river. The group recommended thorough monitoring of fish populations following dam removal, so that management agencies could evaluate the efficacy of natural recolonization.