Acoustic Telemetry Studies of Juvenile Chinook Salmon Survival at the Lower Columbia Projects in 2006

Abstract

In 2006, the Portland District of the U.S. Army Corps of Engineers (USACE) contracted with the Pacific Northwest National Laboratory (PNNL) to conduct three studies using acoustic telemetry to estimate detection probabilities and survival of juvenile Chinook salmon at three hydropower projects on the lower Columbia River. The primary goals were to estimate detection and survival probabilities based on sampling with Juvenile Salmon Acoustic Telemetry System (JSATS) equipment, assess the feasibility of using JSATS for survival studies, and estimate sample sizes needed to obtain a desired level of precision in future studies. Tagging We conducted acoustic-telemetry survival studies on yearling and sub-yearling Chinook salmon at John Day Dam (JDA), The Dalles Dam (TDA), and Bonneville Dam (BON). We surgically implanted 2,501 yearling Chinook salmon in spring and 2,502 sub-yearling Chinook salmon in summer with passive integrated transponder (PIT) and JSATS acoustic tags. Fish were collected and tagged at the John Day Dam Smolt Monitoring Facility (SMF), and unintentional tagging mortality averaged 0.6% in spring and 0.7% in summer. Tagging seasons encompassed the peaks of the spring and summer runs of juvenile Chinook salmon. The spring tagging season was from May 13 to June 6, 2006, and targeted the yearling Chinook run, which peaked between May 20 and June 1, 2006. A 95-mm minimum length limitation on tagging did not restrict the lengths of fish that could be tagged in the spring, and the length frequencies of tagged and untagged yearling Chinook salmon in the juvenile bypass system (JBS) samples were very similar. The summer tagging season was from June 11 to July 13, 2006, and targeted the subyearling Chinook run, which peaked around July 1. The 95-mm minimum tagging length effectively eliminated about 23% of the run-of-river sub-yearlings from the sample because they were too small to tag without increasing tagging mortality. Tagging must include 80 to 100 mm subyearlings to be fully representative of the runof-river population at JDA in summer. All fish tagged in this study and released at or below JDA were implanted with JSATS tags that transmitted a coded signal transmitting once every 5 seconds (5 s tags) that were expected to last about 30 days, and fish that were released into the Snake River by other studies were implanted with tags that transmitted once every 10 s. We conducted a tag-life study using 100 10 s tags and 100 5 s tags randomly sampled from lots allocated to survival studies. The tag-life study verified that most tags lasted about as long as expected. All 10-s tags sampled from lots of tags implanted in Snake River fish lasted at least 57 days relative to an expected 55 days, and all the 5-s tags exceeded the expected 30-day life by about 5 days. No tag-life correction was needed or used for the 2006 survival studies in spring or summer because over 99% of tagged fish exited the study area before tags expired. Tag life and survivorship curves are presented in Appendix A.

Survival Rates of Juvenile Salmonids Passing Through the Bonneville Dam and Spillway in 2008

“…As in previous studies (Ploskey et al 2007b;, tag-detection data from JSATS autonomous nodes were processed in two ways as a quality-control measure, and we found no significant difference in detection and survival estimates based upon detection histories. One method involved using TagViz software, and the other involved processing data with programs written in the Statistical Analysis System (SAS) code.…”

“…In 2006, a total survival evaluation looked at 100,000-cfs spill for 24 hours/day in spring and a modified BiOp spill with larger gate openings in summer. Unfortunately, the effects of spill condition were confounded by a typical decline in the survival rate of FC as summer progressed (Ploskey et al 2007b). …”

Evaluation of a Behavioral Guidance Structure at Bonneville Dam Second Powerhouse including Passage Survival of Juvenile Salmon and Steelhead using Acoustic Telemetry, 2008

“…As in previous studies (Ploskey et al 2007b;Ploskey et al 2009, tag-detection data from JSATS autonomous nodes were processed in two ways as a quality-control measure, and we found no significant difference in detection and survival estimates based upon detection histories. One method involved using TagViz software, and the other involved processing data with programs written in the Statistical Analysis System (SAS) code.…”

“…The flow conditions created by the BGS likely contributed to the observed passage distributions, especially when comparing passage at the dam to previous radio-telemetry and hydroacoustic studies (Ploskey 2007a). Those studies showed a strong southerly preference for passage highly skewed toward turbine units 11-12 at the peak, with the tail of the distribution extending toward unit 18.…”

“…The most striking and significant was the strong decline in survival that was observed in subyearlings over the summer season for all routes passing through B2. As noted by Ploskey et al in 2007b, the loss of fish to residualization (reverse smoltification) in summer could produce such a trend. However, Ploskey et al also found the survival correlation with B2 discharge was significant, as was found in the summer of 2008 (r 2 = 0.64).…”