Record Details
Life history variation and movement among three populations of redband trout (Oncorhynchus mykiss gairdneri) in the middle Deschutes Basin, Oregon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Life history variation and movement among three populations of redband trout (Oncorhynchus mykiss gairdneri) in the middle Deschutes Basin, Oregon |
| Names |
Groves, Kristy L.
(creator) Shields, Barbara A. (advisor) Olson, Robert E. (advisor) |
| Date Issued | 2000-06-01 (iso8601) |
| Note | Graduation date: 2001 |
| Abstract | Redband trout (Oncorhynchus mykiss gairdneri) are found over a wide range of environmental conditions and are known for their variability in life history traits among watersheds or even within streams. Life history traits and population structure of these trout can be influenced by a variety of anthropogenic changes including habitat degradation and habitat fragmentation. In 1964, the construction of Round Butte Dam created a large reservoir (Lake Billy Chinook) at the junctions of the Crooked, Deschutes, and Metolius Rivers. It is unknown what effect the creation of Lake Billy Chinook had on the native population structure of redband trout in this area because no baseline data were collected before the construction of the dam. The fate of a population of summer run of steelhead trapped above the dam also remains unknown. This study focused on determining if Lake Billy Chinook presented a barrier to interactions among populations in the middle Deschutes, lower Metolius, and lower Crooked Rivers by examining movement of tagged redband trout within the system. The sub-populations of trout from the three major tributaries of Lake Billy Chinook were also examined to determine if they could be separated and identified based on biological characters including life history characters, morphometric characters, and parasite faunal assemblages. The large number of redband trout observed moving into arms other than where they were originally tagged suggests that the reservoir does not act as a barrier to ecological interactions among the sub-populations of redband trout in this system. Despite some mixing observed among locations, three sub-populations of redband trout were identified in this system. Redband trout captured in the Deschutes and Crooked Rivers were similar in morphology and in all life history characters examined. However, these populations could be separated based on parasite assemblages, indicating some ecological separation. Redband trout captured upstream in the Metolius River were morphologically unique from other populations and can be identified most readily using simple morphological measurements. Some differences in morphology, growth, movement patterns, fecundity and disease and parasites suggest the possible continued existence of a native, landlocked population of steelhead above Round Butte Dam. |
| Genre | Thesis/Dissertation |
| Topic | Trout -- Oregon -- Deschutes River Watershed |
| Identifier | http://hdl.handle.net/1957/20455 |
