Ian G. Jezorek’s research while affiliated with United States Geological Survey and other places

Chinook Salmon spawning in the White Salmon River consist of members of three historically distinct populations: spring Chinook Salmon, Tule fall Chinook Salmon and Upriver Bright (URB) fall Chinook Salmon. Previous work examined juveniles captured in 2006-2008 and reported hybridization between introduced URBs, and the native threatened Tules. Recent increases in nearby hatchery URB release numbers raised the question of whether hybridization rates were increasing. We estimated hybrid frequencies among juveniles collected in the lower White Salmon River between 2016 and 2019. We also evaluated the frequencies at which non-target fish and hybrids were incorporated into the broodstocks of adjacent hatcheries. We observed that frequencies of hybrids in juvenile samples from the White Salmon River were greater in 2017-2019 (17-32%) than they had been in 2006-2008 (4-15%), but that a few (2/9) comparisons exhibited overlapping confidence intervals, suggesting that the rate has increased over time, but also that more sampling is needed to understand the importance of year-to-year variation. Further, differences in the habitat following dam removal and in the sampling sites complicated interpretation of our results. Examination of broodstocks of nearby hatcheries revealed low rates (< 0.5%) of incorporation of non-target populations and higher rates (< 9.0%) of incorporation of hybrids into those broodstocks. The relative compositions of all hatchery and natural-origin collections were similar: most individuals were one of the two parental stocks, a very small fraction were F1 hybrids, and a larger minority fraction were back-crosses. This pattern, in the context of hybridization which we know has been happening for several generations, is consistent with a hypothesis of selection against hybrids in which F1 hybrids are less fit than backcross hybrids.

Background In fish tagging studies, tag size limits the size of fish that can be tagged, the fraction of a population that can be represented, and ultimately inferences that can be made about the study population, particularly when juvenile fish are the subject of interest. Introduction of an 8-mm passive integrated transponder (PIT) reduced the minimum taggable size of fish, but it has not been evaluated in field trials. We evaluated the growth and survival of age-0 Oncorhynchus mykiss tagged with 8-mm PIT tags in four streams in southwest Washington, USA. Results A total of 351 PIT tagged fish and 340 control fish (marked with pelvic fin clips) were released, but recapture rates were low, particularly for control fish. Growth in length and mass did not differ between small (42–54 mm) and large (55–64 mm) PIT tagged fish. There was a slightly positive, but weak, relation between tag burden and growth in mass; however, there was considerable variability in this relation (R² = 0.115). Summer to autumn joint probability of fish surviving and remaining in the study area estimated with a Bayesian mark-recapture model ranged from 0.228 to 0.478 in study streams. We found no significant relation between tag burden and survival, suggesting neither tag burden nor fish size at tagging affected survival. Conclusions Although this study was limited in scope, it provided insight into how age-0 O. mykiss tagged with 8-mm PIT tags grew and survived under natural conditions. We showed that fish as small as 42 mm could be tagged without detrimental effects, which should allow researchers to represent a larger portion of study populations through PIT tagging.

Biotic and abiotic factors influence fish populations and distributions. Concerns have been raised about the influence of hatchery fish on wild populations. Carson National Fish Hatchery produces spring Chinook salmon Oncorhynchus tshawytscha in the Wind River, Washington, and some spawn in the river. Managers were concerned that Chinook salmon could negatively affect wild steelhead O. mykiss and that a self-sustaining population of Chinook salmon may develop. Our objectives were to assess: 1) the distribution and populations of juvenile spring Chinook salmon and juvenile steelhead in the upper Wind River; 2) the influence of stream flow and of each population on the other; and 3) if Chinook salmon populations were self-sustaining. We snorkeled to determine distribution and abundance. Flow in the fall influenced upstream distribution and abundance of juvenile Chinook salmon. Juvenile Chinook salmon densities were consistently low (range 0.0 to 5.7 fish 100 m-2) and not influenced by number of spawners, winter flow magnitude, or steelhead abundance. Juvenile steelhead were distributed through the study section each year. Age-0 and age-1 steelhead densities (age-0 range: 0.04 to 37.0 fish 100 m-2; age-1 range: 0.02 to 6.21 fish 100 m-2) were consistently higher than for juvenile Chinook salmon. Steelhead spawner abundance positively influenced juvenile steelhead abundance. During this study, Chinook salmon in the Wind River appear to have had little effect on steelhead. Low juvenile Chinook salmon abundance and a lack of a spawner-to-juvenile relationship suggest Chinook salmon are not self-sustaining and potential for such a population is low under current conditions.

Big Spring spinedace (Lepidomeda mollispinis pratensis) is a cyprinid whose entire population occurs within a section of Meadow Valley Wash, Nevada. Other spinedace species have suffered population and range declines (one species is extinct). Managers, concerned about the vulnerability of Big Spring spinedace, have considered habitat restoration actions or translocation, but they have lacked data on distribution or habitat use. Our study occurred in an 8.2-km section of Meadow Valley Wash, including about 7.2 km in Condor Canyon and 0.8 km upstream of the canyon. Big Spring spinedace were present upstream of the currently listed critical habitat, including in the tributary Kill Wash. We found no Big Spring spinedace in the lower 3.3 km of Condor Canyon. We tagged Big Spring spinedace >= 70 mm fork length (range 70-103 mm) with passive integrated transponder tags during October 2008 (n = 100) and March 2009 (n = 103) to document movement. At least 47 of these individuals moved from their release location (up to 2 km). Thirty-nine individuals moved to Kill Wash or the confluence area with Meadow Valley Wash. Ninety-three percent of movement occurred in spring 2009. Fish moved both upstream and downstream. We found no movement downstream over a small waterfall at river km 7.9 and recorded only one fish that moved downstream over Delmue Falls (a 12-m drop) at river km 6.1. At the time of tagging, there was no significant difference in fork length or condition between Big Spring Spinedace that were later detected moving and those not detected moving. We found no significant difference in fork length or condition at time of tagging of Big Spring spinedace = 70 mm fork length that were detected moving and those not detected moving. Kill Wash and its confluence area appeared important to Big Spring spinedace; connectivity with these areas may be key to species persistence. These areas may provide a habitat template for restoration or translocation. The lower 3.3 km of Meadow Valley Wash in Condor Canyon may be a good candidate section for habitat restoration actions.

This report summarizes work completed by U.S. Geological Survey's Columbia River Research Laboratory (USGS-CRRL) in the Wind River subbasin during the period April 2005 through March 2006 under Bonneville Power Administration (BPA) contract 22095. During this period, we collected temperature, flow, and habitat data to characterize habitat condition and variation within and among tributaries and mainstem sections in the Wind River subbasin. We also conducted electrofishing and snorkeling surveys to determine juvenile salmonid populations within select study areas throughout the subbasin. Portions of this work were completed with additional funding from U.S. Fish and Wildlife Service (USFWS) and the Lower Columbia Fish Enhancement Group (LCFEG). A statement of work (SOW) was submitted to BPA in March 2005 that outlined work to be performed by USGS-CRRL. The SOW was organized by work elements, with each describing a research task. This report summarizes the progress completed under each work element.

During 2004, researchers from U.S. Geological Survey's Columbia River Research Laboratory (USGS-CRRL) collected temperature, flow, and habitat data to characterize physical habitat condition and variation within and among tributaries and mainstem sections in the Wind River subbasin. Juvenile salmonid population surveys were conducted within select study areas throughout the subbasin. We expanded our survey coverage of the mainstem Wind River to a reach in the vicinity of Carson National Fish Hatchery to assess effects of non-indigenous Chinook on native steelhead. These efforts add to a database of habitat and fish data collected in the Wind River since 1996. This research contributes to the Wind River Restoration Project, which includes active stream habitat restoration and monitoring of adult and juvenile steelhead populations. We maintained a network of 32 thermographs in the Wind River subbasin during 2004. Additionally, Underwood Conservation District provided us with data from seven thermographs that they maintained during 2004. Thermograph data are identifying areas with chronic high water temperatures and stream sections where high rates of warming are occurring. During 2004, water temperatures at 26 thermograph sites exceeded the 16 C limit for surface waters set by the Washington Department of Ecology. Water temperatures exceeded 20 C at five sites in the Trout Creek watershed. Our thermograph dataset includes information from as early as 1996 at some sites and has become a valuable long-term dataset, which will be crucial in determining bioenergetic relationships with habitat and life-histories. We have monitored salmonid populations throughout the Wind River subbasin by electrofishing and snorkeling. We electrofished four stream sections for population estimates during 2004. In these sections, and others where we simply collected fish without a population estimate, we tagged juvenile steelhead and Chinook salmon with Passive Integrated Transponder (PIT) tags to track growth and movement of individuals. We snorkeled nine stream sections during 2004. Juvenile steelhead populations have varied greatly between streams and between years. Numbers of age-0 steelhead have increased substantially since 2000 within the MINE reach (rkm 35.0-40.0) section of the upper Wind River. Because of potential negative interactions with steelhead, naturally spawned populations of introduced juvenile Chinook salmon are of concern in the mainstem of the Wind River. During 2004, we deployed over 3,000 PIT tags in the Wind River subbasin, primarily in juvenile steelhead, but also in juvenile Chinook. We are compiling a dataset of recapture information on these tagged fish as well as interrogation information from Bonneville Dam and other sites. The habitat and fish data collected have been used in Ecosystem Diagnosis and Treatment modeling efforts, the Wind River Subbasin Plan, and the Total Maximum Daily Load report from Washington Department of Ecology. Continued monitoring of changes in habitat, combined with data on fish populations, will help guide planning efforts of land and fish managers. As long-term active and passive restoration actions are implemented in the Wind River and its tributaries, these data will provide the ability to measure change. Because the Wind River subbasin has no steelhead hatchery or supplementation, these data will be useful to compare population trends in subbasins with hatchery or supplementation management.

This report summarizes work completed by U.S. Geological Survey's Columbia River Research Laboratory (USGS-CRRL) in the Wind River subbasin during the period April 2006 through March 2007 under Bonneville Power Administration (BPA) contract 26922. During this period, we collected temperature, flow, and habitat data to characterize physical habitat condition and variation within and among tributaries and mainstem sections in the Wind River subbasin. We also conducted electrofishing and snorkeling surveys to determine juvenile salmonid populations within select study areas throughout the subbasin. Portions of this work were completed with additional funding from U.S. Fish and Wildlife Service (USFWS) and the Lower Columbia Fish Enhancement Group (LCFEG). Funding from USFWS was for work to contribute to a study of potential interactions between introduced Chinook salmon Oncorhynchus tshawytscha and wild steelhead O. mykiss. Funding from LCFEG was for work to evaluate the effects of nutrient enrichment in small streams. A statement of work (SOW) was submitted to BPA in March 2006 that outlined work to be performed by USGS-CRRL. The SOW was organized by work elements, with each describing a research task. This report summarizes the progress completed under each work element.

We tested the performance of two stationary interrogation systems designed for detecting the movement of fish with passive integrated transponder (PIT) tags. These systems allowed us to determine the direction of fish movement with high detection efficiency and high precision in a dynamic stream environment. We describe an indirect method for deriving an estimate for detection efficiency and the associated variance that does not rely on a known number of fish passing the system. By using six antennas arranged in a longitudinal series of three arrays, we attained detection efficiencies for downstream- and upstream-moving fish exceeding 96% during high-flow periods and approached 100% during low-flow periods for the two interrogation systems we tested. Because these systems did not rely on structural components, such as bridges or culverts, they were readily adaptable to remote, natural stream sites. Because of built-in redundancy, these systems were able to perform even with a loss of one or more antennas owing to dislodgement or electrical failure. However, the reduction in redundancy resulted in decreased efficiency and precision and the potential loss of ability to determine the direction of fish movement. What we learned about these systems should be applicable to a wide variety of other antenna configurations and to other types of PIT tags and transceivers.