The Confederated Tribes of the Umatilla Indian Reservation (CTUIR) is funded by Bonneville Power Administration (BPA) to conduct a telemetry study to monitor the movement and habitat use by adult steelhead in the Walla Walla Basin and to evaluate their effectiveness of three recently constructed fish passage facilities on the Walla Walla River at Burlingame Dam, Nursery Bridge Dam, and Little Walla Walla River Diversion. This project is a cooperative effort among CTUIR’s Fisheries Program, Oregon Department of Fish and Wildlife, Washington Department of Fish and Wildlife, Walla Walla Basin Watershed Council, the Walla Walla River Irrigation District, Gardena Farms Irrigation District 13 and the University of Idaho.
Since 2001, CTUIR has maintained up to 12 telemetry stations throughout the Umatilla Basin. Individually, digitally encoded radio-tags combined with the strategic deployment of telemetry stations allows for tracking of individual fish. Multiple antennas at each station show if fish use ladders or jump over structures as well as record how long fish hold below a structure before moving past it. Mobile tracking from the air and on the ground will locate fish away from stations and follow individuals throughout the basin. During my internship with CTUIR, I worked with Project leader Brian Mahoney and field biologists Mike Lambert and Travis Olsen.
The first month or so my internship was rather slow, for several reasons. One reason was that the fall migration of steelhead does not really pick up until October, so there was no tagging in September. Another factor which contributed to the internship starting slowly was the fact that I had to go to the hospital and had to miss a meeting scheduled with my internship advisor for the project, Jesse Schwartz. In the meantime, I was given several internet sites to look at, which both increased my knowledge of the life cycle and migratory habits of the steelhead as well as gave me a better idea as to the purpose of this study.
The 4 main aspects which this study examines are:
1) Delay of Passage:
The ability of structures, particularly artificial ladders, to allow the passage of steelhead through the river. Examining the effectiveness of fish passage in the Walla Walla Basin will help to develop effective strategies for fisheries and flow enhancement. The information gained in the past years has been used to facilitate adaptive management efforts in the basin and identify fish passage barriers remaining to be addressed.
2) The Migratory passages as a Whole
Examining the migratory patterns of the steelhead is also important to this study. Understanding of the seasonal special distribution of wild steelhead populations is used to help prioritize habitat improvements, assess the efficacy of recent passage improvements, assist in difficult water management decisions, and gain more knowledge of listed fish populations.
3) Flow Requirements
This study also examines the amount of water flow steelhead need to successfully navigate the river, particularly the Walla Walla main stem. Water diversion has had a particularly negative impact on steelhead migration in the spring.
4) Individual Data
Lastly, this study documents all the characteristics of each individual steelhead that is tagged. These characteristics include: rather the fish is wild or from a hatchery, rather it is male or female, it’s dimensions, and overall condition. This information gives a better idea of the population as a whole.
In October, I met with Project Leader Brian Mahoney and biologists Mike Lambert and Travis Olsen, and from this point on, the internship really took off. I was able to go tagging in the field with Brian and Travis several times, and I also worked on data entry jobs at the CTUIR office.
In order to radio-tag fish, we went out in the CTUIR boat in the Walla Walla River and used tangle nets to catch the steelhead. Besides catching steelhead, we also inadvertently caught many suckerfish which were all released back into the river. Once a steelhead was caught, the radio tag was inserted into the fish’s stomach (the tags were lubricated with olive oil to aid insertion). To insert a tag, the steelhead is placed in a cooler full of water and inverted, which immediately calms them down. A wooden stick is helpful in getting the tag down into the stomach of the steelhead but requires a careful touch: if not pushed in far enough, the steelhead can simply spit out the $200 tag when released back into the water, but if the tag is pushed too far in, it can damage the stomach of the fish. The goal during the tagging was to cause the least amount of trauma to the steelhead.
Once inserted, the tag’s transmitting antenna ran back up the bullet and out the mouth, laying flush along the body of the fish. The radio tags used were Lotek MCFT-3A radio transmitters and each transmitted a unique code on a frequency of 150.210 MHz. Most transmitters were fitted with a section of surgical tubing to help anchor them within the fish’s stomach to minimize tag regurgitation. We were able to insert the transmitters quickly, with minimal apparent stress and without anesthetizing the fish. Each fish was held for about 15 minutes in a cooler full of water while tag retention was visually confirmed and then the fish was released at the capture site. We recorded date, tag number, capture location and method, fish condition, sex, fork length, water temperature, and any additional comments.
After fish were tagged, we were able to chart their progress up and down the river using the telemetry stations which CTUIR has established in the basin. This tracking was done by land, in boat and by air. CTUIR will continue to chart their progress throughout the year.
I feel that this internship was a rewarding experience. I learned a great deal about steelhead migration, and all the factors which can have an impact on it. It was also a great chance to gain some experience in the field. Unfortunately, I was not able to go out into the field quite as many times as I wanted to, due to the weather. It was also unfortunate that we got started a little later than we were planning on, but I still feel that I am taking a great deal away from this experience.