Ian G. Jezorek

Measuring 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 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.

Biotic and Abiotic Influences on Abundance and Distribution of Nonnative Chinook Salmon and Native ESA-Listed Steelhead in the Wind River, Washington

Abstract 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.

Distribution and movement of Big Spring spinedace ( Lepidomeda mollispinis pratensis ) in Condor Canyon, Meadow Valley Wash, Nevada

ABSTRACT. 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.

Wind River Watershed Restoration : 2000-2001 Annual Report.

This report focuses on work conducted in 2000 and 2001 by the U.S. Geological Surveys Columbia River Research Laboratory (USGS-CRRL) as part of the Wind River Watershed Restoration Project. The project started in the early 1990s, and has been funded through the Bonneville Power Administration (BPA) since 1998. The project is a comprehensive effort involving public and private entities seeking to restore water quality and fishery resources in the Wind River subbasin through cooperative actions. Project elements include coordination, watershed assessment, restoration, monitoring, and education. In addition to USGS-CRRL, other BPA-funded entities involved with implementing project components are the Underwood Conservation District (UCD), USDA Forest Service (USFS), and Washington Department of Fish and Wildlife (WDFW). To describe the activities and accomplishments of the USGS-CRRL portion of the project, we partitioned the 2000-2001 annual report into two pieces: Report A and Report B. In Report A, we provide information on flow, temperature, and habitat conditions in the Wind River subbasin. Personnel from CRRL monitored flows at 12 sites in 2000 and 17 sites in 2001. Flow measurements were generally taken every two weeks during June through October, which allowed tracking of the descending limb of the hydrograph in late spring, through the base low flow period in summer, and the start of the ascending limb of the hydrograph in fall. We maintained a large array of water-temperature sites in the Wind River subbasin, including data from 25 thermographs in 2000 and 27 thermographs in 2001. We completed stream reach surveys on 14.0 km in 2000 and 6.1 km in 2001. Our focus for these reach surveys has been on the upper Trout Creek and upper Wind River watersheds, though some reach surveys have occurred in the Panther Creek watershed. Data generated by these reach surveys include stream width, stream gradient, large woody debris frequency, pool frequency, canopy shade, and riparian vegetation. Data on flow, temperature, and stream reaches have been collected by USGS-CRRL personnel since 1996. Where appropriate, we have compared the data collected in 2000-2001 to those data available from our earlier work.