Kristen Kirkby May 5, 2005

Tagging, Trapping, and Monitoring Juvenile Salmon on the Walla Walla River
With the Confederated Tribes of the Umatilla Indian Reservation


In order to reintroduce and enhance the population of Chinook salmon in the Walla Walla River, the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) Fisheries program runs a number of projects throughout the course of the year. My internship with the Tribe focused mainly on a juvenile project run by biologist Mike Lambert. This project’s main goals are to estimate the abundance, timing, and survival of juvenile salmon migrating from the Walla Walla River to the Columbia River. Special focus will be placed on the comparison of the downstream passage of hatchery and wild Chinook juveniles along with a consideration of the effects of the Columbia River dams on downstream juvenile migration.

My own goals for this internship were to gain firsthand experience with biological field research and to get involved with regional issues and efforts. As a biology major with an interest in ecology, I wanted the chance to see the ups and downs of working in the field with living organisms and working to produce worthwhile data. As an environmental studies student, I hoped to better understand the complex relationship between the ecology and politics of salmon and water issues in the Walla Walla region. This internship offered me a chance to do both.



The Tribe runs four, eight foot rotary screw traps throughout the Walla Walla region. Two of these traps run on the Walla Walla with one outside of Milton-Freewater towards Harris Park and the second at the lower end of the Walla Walla before it enters the Columbia at Pierce RV. These traps are placed in the high flow area of the river and are connected to the bank by a system of cables. Fish swim into the trap and are spun into a collection tank at the back. Each day, traps are cleaned of any built-up debris and the collection/holding tank is checked for fish. A survey of water temperature, water color, the amount of debris in the river, and water speed is taken while fish are collected and brought ashore. Fish that are not salmon or steelhead are counted and released back into the river.

The salmon and steelhead are then anesthetized with a solution of tricaine methane-sulfonate in order to ease the stress associated with handling and tagging. Fish are checked for previous tags, and, if they have not yet received one, a small PIT tag is injected into the body cavity of Chinook greater than 75 mm and steelhead smolt of size to be age two and over. The fish are then measured and weighed and a scale sample is taken for further genetic analysis if necessary. All of this data is recorded in both a hard and an electronic copy for later analysis.

In order to make an estimation of the numbers of fish traveling in the river, trap efficiency must be determined. Each week some tagged fish are released up stream of the trap and by calculating the percent of these fish that were trapped for a second time, researchers can come up with a rough estimate of trap efficiency. This number allows the project to extrapolate the total number of fish traveling down river from their smaller catch numbers. During the rest of the week, the fish are released downstream of the trap to continue their normal migration. PIT tag signals can be picked up throughout the Columbia River by detecting devices placed in infrastructure such as fish ladders at various dams. This shared technology allows fisheries throughout the Northwest to monitor the movement of tagged fish and to study the effects of dams.

My role throughout the internship was mainly one of a student. I learned how to check the trap, assess the river, and take down hard copy data of fish measurements. I helped to catch fish from the trap, carry them to and from the river, and keep an eye on them throughout the process. I also had the opportunity to learn about the fisheries program both by talking with the field techs and the biologists, and also by going out to the main office and to several other traps in the Walla Walla River system. Although I had no part in data analysis, the goals and progress of the project was clearly explained and I was provided with data to satisfy my own curiosity on the findings of the project both in terms of how many of what fish passed through the trap as well as a site that allows me to track fish that were tagged while I interned.



It interests me greatly that this project looks at salmon analysis in terms of anthropogenic alterations to their environment. PIT tagging allows researchers the opportunity to study the actual effects of dams on salmon, not just those effects estimated by dam builders or threatened by environmentalists. As a biology student I think a scientific understanding of things is incredibly important for issues such as this. As an environmental studies student, I also recognize the importance of involving and sharing this information with parties that might not normally be interested in salmon or perhaps those that have a different sort of interest in these fish (economics, etc).

I hope very much that solid, conclusive data comes out of this project and that it is shared not only with other fisheries programs, but also with the public who should have an interest in this issue as it is one that effects not only the ecology of the region but the economy and the political scene as well.



I’ve had a great time with this internship and hope to continue working with CTUIR’s fishery department this coming fall. As I’ve mentioned before, the draw of this project for me was both an interest in biology, as well as a desire to get involved in the work and issues of this community. Growing up in Washington I’ve always had positive associations with salmon and through Whitman classes I’ve learned about the history and current politics behind the issue. Important though both of these experiences are, it’s been both educational and inspiring to be able to work in such close proximity to these amazing creatures and to further explore their home in the Walla Walla River.

I definitely recommend this project to everyone, particularly those interested in a career with both a field and office component. I would suggest, however, some preliminary study on the issue as well as the species. Also, get to the office as soon as you can and take a look at past data. It’s interesting and very helpful to have an understanding of the bigger picture of you own particular project, along with some knowledge of other projects going on as well. A consideration of the preliminary data suggests just how much work goes on in the office as well as the field and understanding the analysis that must happen with that data gives a truer picture still of the amazing amount of effort involved in such a project. Lastly, enjoy the time you spend out in the field, it’s great to get out on the river and explore the ecology of this region.