Ian Jezorek
(He/him)I am a Fisheries Biologist working extensively with small stream and river environments with an emphasis on salmonids, both resident and anadromous. Research includes population, behavior and responses to restoration actions including dam removals. Research tools include snorkeling, electrofishing, and trapping to count and capture fish.
I have focused much on PIT tagging and radio tagging of juvenile and adult salmonids. I have been involved in design, construction, deployment, and operation of many instream PIT-tag interrogation systems.
I am currently involved with studies focusing on steelhead populations, life histories, habitat, and limiting factors in the Wind River, WA as part of a multi-agency effort to restore steelhead populations in the Wind River. A portion of the Wind River work has focused on interaction between juvenile steelhead an introduced run of hatchery spring Chinook salmon. A current focus of work in the Wind River and the White Salmon River, WA is on assessing salmonid population response to dam removal, which has occurred in both watersheds. Much data on salmonid ecology and life-histories is gathered through tagging fish with Passive Integrated Transponder (PIT) tags. Instream PIT tag detection systems are a tool we have employed in many watersheds and continue to do so in several local watersheds.
Professional Experience
1997 to Present - Fish Biologist, U.S. Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA
1996-1997 - Biologist 1, Johnson Controls World Services Inc. Stationed at Columbia River Research Laboratory, Cook, WA
1995. Biological Aid, Oregon Department of Fish and Wildlife, Research Division, The Dalles, OR
1994. Fisheries Technician, USDA Forest Service, Ochoco Ranger Station, Prineville, OR
1993. Biological Aid, Idaho Department of Fish and Game, Lewiston, ID
Education and Certifications
B.S. 1992. Fishery Science, Virginia Polytechnic Institute and State University
Science and Products
Biotic and abiotic influences on abundance and distribution of nonnative Chinook salmon and native ESA-listed steelhead in the Wind River, Washington
Wind River subbasin restoration: U.S. Geological Survey annual report November 2012 through December 2013
Distribution and movement of Big Spring spinedace (Lepidomeda mollispinis pratensis) in Condor Canyon, Meadow Valley Wash, Nevada
Wind River watershed restoration. Annual report. November 2011 through October 2012
Hood River PIT-tag interrogation system efficiency study. Annual report of U.S. Geological Survey activities: November 2010-October 2011
Wind River watershed restoration: Annual report of U.S. Geological Survey activities November 2010 – October 2011
Big Spring spinedace and associated fish populations and habitat conditions in Condor Canyon, Meadow Valley Wash, Nevada
Wind River watershed restoration, annual report November 2009 to October 2010.
Wild Steelhead and introduced spring Chinook Salmon in the Wind River, Washington: Overlapping populations and interactions
Wind River water restoration, Annual report November 2008 to October 2009.
Wind River watershed restoration, annual report April 2007 to October 2008
Measuring the performance of two stationary interrogation systems for detecting downstream and upstream movement of PIT-tagged salmonids
Science and Products
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Filter Total Items: 42
Biotic and abiotic influences on abundance and distribution of nonnative Chinook salmon and native ESA-listed steelhead in the Wind River, Washington
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 andAuthorsIan G. Jezorek, Patrick J. ConnollyWind River subbasin restoration: U.S. Geological Survey annual report November 2012 through December 2013
Executive Summary The Wind River subbasin in southwest Washington State provides habitat for a population of wild Lower Columbia River steelhead Oncorhynchus mykiss. There have been no hatchery steelhead planted in the Wind River subbasin since 1994, and hatchery adults are estimated to be less than one percent of adults in any year (pers comm. Thomas Buehrens, Washington Department of Fish and WiAuthorsIan G. Jezorek, Patrick J. ConnollyDistribution and movement of Big Spring spinedace (Lepidomeda mollispinis pratensis) in Condor Canyon, Meadow Valley Wash, Nevada
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 dataAuthorsIan G. Jezorek, Patrick J. ConnollyWind River watershed restoration. Annual report. November 2011 through October 2012
Introduction This report summarizes work by U.S. Geological Survey’s Columbia River Research Laboratory (USGS-CRRL) in the Wind River subbasin, from November 2011 through October 2012. Funding was provided by Bonneville Power Administration (BPA) under contract 55275. The primary focus of USGS activities during this time was tagging of parr steelhead Oncorhynchus mykiss with Passive Integrated TraAuthorsIan G. Jezorek, Patrick J. ConnollyHood River PIT-tag interrogation system efficiency study. Annual report of U.S. Geological Survey activities: November 2010-October 2011
Introduction During summer 2010, an agreement was made between the US Geological SurveyColumbia River Research Laboratory (USGS-CRRL) and the Confederated Tribes of the Warm Springs (CTWS) to operate an experimental Passive Integrated Transponder (PIT)-tag interrogation system (PTIS) near the mouth of the Hood River for a year and provide fishdetection efficiency estimates (Bonneville Power AdminiAuthorsIan G. Jezorek, Patrick J. ConnollyWind River watershed restoration: Annual report of U.S. Geological Survey activities November 2010 – October 2011
This report summarizes work completed by U.S. Geological Survey’s Columbia River Research Laboratory (USGS-CRRL) in the Wind River subbasin during November 2010 through October 2011 under Bonneville Power Administration (BPA) contract 40481. The primary focus of USGS activities during this contract was on tagging of juvenile steelhead Oncorhynchus mykiss with Passive Integrated Transponder (PIT) tAuthorsIan G. Jezorek, Patrick J. Connolly, Carrie S. MunzBig Spring spinedace and associated fish populations and habitat conditions in Condor Canyon, Meadow Valley Wash, Nevada
Executive Summary: This project was designed to document habitat conditions and populations of native and non-native fish within the 8-kilometer Condor Canyon section of Meadow Valley Wash, Nevada, with an emphasis on Big Spring spinedace (Lepidomeda mollispinis pratensis). Other native fish present were speckled dace (Rhinichthys osculus) and desert sucker (Catostomus clarki). Big Spring spinedacAuthorsIan G. Jezorek, Patrick J. Connolly, Carrie S. Munz, Chris DixonWind River watershed restoration, annual report November 2009 to October 2010.
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 November 2009 through October 2010 under Bonneville Power Administration (BPA) contract 46102. Long term research in the Wind River has focused on assessments of steelhead/rainbow trout Oncorhynchus mykiss populations, interactions with introAuthorsP.J. Connolly, I.G. JezorekWild Steelhead and introduced spring Chinook Salmon in the Wind River, Washington: Overlapping populations and interactions
We investigated interactions of introduced juvenile spring Chinook salmon Oncorhynchus tshawytscha with wild juvenile steelhead O. mykiss in the upper Wind River watershed (rkm 24.6 to rkm 43.8), Washington. Our objective was to determine if the presence of introduced spring Chinook salmon influenced populations of wild juvenile steelhead and if other biotic or abiotic factors influenced distributAuthorsI.G. Jezorek, P.J. ConnollyWind River water restoration, Annual report November 2008 to October 2009.
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 November 2008 through October 2009 under Bonneville Power Administration (BPA) contract 41038. Long term research in the Wind River has focused on assessments of steelhead/rainbow trout Oncorhynchus mykiss populations, interactions with intrAuthorsP.J. Connolly, I.G. Jezorek, C.S. MunzWind River watershed restoration, annual report April 2007 to October 2008
No abstract availableAuthorsI.G. Jezorek, C.S. Munz, P.J. ConnollyMeasuring the performance of two stationary interrogation systems for detecting downstream and upstream movement of PIT-tagged salmonids
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 aAuthorsP.J. Connolly, I.G. Jezorek, K.D. Martens, E.F. Prentice - News