Adam G. Seaburg

Performance Assessment of Suture Type, Water Temperature, and Surgeon Skill in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

Abstract This study assessed performance of seven suture types in subyearling Chinook salmon Oncorhynchus tshawytscha implanted with acoustic microtransmitters and held at two water temperatures (12°C and 17°C). Nonabsorbable (Ethilon) and absorbable (Monocryl) monofilament sutures and nonabsorbable (Nurolon and silk) and absorbable (Vicryl, Vicryl Plus, and Vicryl Rapide) braided sutures were used to close incisions in Chinook salmon. When differences existed among suture types, tag and suture retention were generally highest for monofilament sutures. Wound inflammation and ulceration were generally lower for Ethilon and Monocryl than for most of the braided sutures. In this study, Nurolon (braided) often resulted in low wound inflammation and ulceration, although suture retention was poor. Generally, fish held in 12°C water had more desirable postsurgery healing characteristics (i.e., higher tag and suture retention; lower incision openness, wound inflammation, and ulceration) at 7 and 14 d postsurgery ...

Quantifying Mortal Injury of Juvenile Chinook Salmon Exposed to Simulated Hydro-Turbine Passage

Abstract A proportion of juvenile Chinook salmon Oncorhynchus tshawytscha and other salmonids travel through one or more turbines during their seaward migration in the Columbia and Snake rivers. There is limited information on how these fish respond to the hydraulic pressures found during turbine passage events. We exposed juvenile Chinook salmon to varied acclimation pressures and subsequent exposure pressures to mimic the hydraulic pressures of large Kaplan turbines. Additionally, we varied abiotic (total dissolved gas and rate of pressure change) and biotic factors (condition factor, fish length, and fish weight) that may contribute to the incidence of mortal injury associated with fish passage through hydropower turbines. We determined that the main factor associated with the mortal injury of juvenile Chinook salmon during simulated turbine passage was the ratio between the acclimation pressure and the lowest exposure pressure. Condition factor, total dissolved gas, and rate of pressure change were fo...

Optimal Suturing Technique and Number of Sutures for Surgical Implantation of Acoustic Transmitters in Juvenile Salmonids

Abstract The size reduction of acoustic transmitters has led to a reduction in the length of the incision needed to implant a transmitter. Smaller suture knot profiles and fewer sutures may be adequate for closing an incision used to surgically implant an acoustic transmitter. As a result, faster surgery times and reduced tissue trauma could lead to increased survival and decreased infection for implanted fish. The objective of this study was to assess the effects of five suturing techniques on mortality, tag and suture retention, incision openness, ulceration, and redness in juvenile Chinook salmon Oncorhynchus tshawytscha implanted with acoustic transmitters. Suturing was performed by three surgeons, and study fish were held at two water temperatures (12°C and 17°C). Mortality was low and tag retention was high for all treatments on all examination days (7, 14, 21, and 28 d postsurgery). Because there was variation by surgeon in suture retention among treatments, further analyses included only the one s...

The Influence of Tag Presence on the Mortality of Juvenile Chinook Salmon Exposed to Simulated Hydroturbine Passage: Implications for Survival Estimates and Management of Hydroelectric Facilities

Abstract Each year, telemetry tags (acoustic, radio, and passive integrated transponder tags) are surgically implanted into thousands of fish to assess their passage and survival through hydropower facilities. One passage route that is of particular concern is through hydroturbines, where fish may be exposed to a range of potential injuries that include barotraumas from rapid decompression. The change in pressure from acclimation to exposure (nadir) has been identified as an important factor in predicting the likelihood of mortality and injury for juvenile Chinook salmon Oncorhynchus tshawytscha undergoing rapid decompression associated with simulated turbine passage. The presence of telemetry tags has also been shown to influence the likelihood of mortality and injury for juvenile Chinook salmon. We investigated the likelihood of mortality and injury for telemetry-tagged juvenile Chinook salmon that were exposed to a range of pressure changes associated with simulated turbine passage. Several factors wer...

The Effects of Neutrally Buoyant, Externally Attached Transmitters on Swimming Performance and Predator Avoidance of Juvenile Chinook Salmon

Abstract Migrating juvenile salmonids experience rapid decompression that could result in injury or mortality due to barotrauma as they pass turbines at hydropower facilities. Recent research indicates that the risk of injury or mortality due to barotrauma is higher in fish bearing surgically implanted transmitters. Since tagged fish are used to represent the entire population, this tag effect potentially leads to inaccuracies in survival estimates for fish passing turbines. This problem led to development of a novel transmitter, the use of which may eliminate bias associated with the passage of transmitter-bearing fish through turbines. Juvenile Chinook salmon Oncorhynchus tshawytscha were tagged with two different neutrally buoyant, externally attached transmitters (types A and B). The effects of transmitter presence on swimming performance were examined by comparing critical swimming speeds (Ucrit ; an index of prolonged swimming performance) of externally tagged fish, untagged individuals, and fish th...

Survival of seaward-migrating PIT and acoustic-tagged juvenile Chinook salmon in the Snake and Columbia Rivers: an evaluation of length-specific tagging effects

BackgroundAcoustic telemetry is a widely used tool for evaluating the behavior and survival of juvenile salmonids in the Columbia River basin. Thus, it is important to understand how the surgical tagging process and the presence of a transmitter affect survival. This study evaluated the effect of fish length on the survival of yearling and subyearling Chinook salmon during their seaward migrations through the Snake and Columbia Rivers during 2006, 2007, and 2008. Fish were collected at Lower Granite Dam on the Snake River (695 river km from the mouth of the Columbia) and implanted with either only a passive integrated transponder (PIT) tag (PIT fish) or both a PIT tag and an acoustic transmitter (AT fish).ResultsAcross the 3 years, a total of 157,000 yearling and subyearling fish were tagged and designated as PIT fish and 18,500 as AT fish. Survival was estimated from release at Lower Granite Dam to multiple downstream dams using the Cormack–Jolly–Seber single release model, and analysis of variance was used to test for differences among length classes for both tag types. No length-specific tag effect was detected between PIT and AT fish (that is, length affected the survival of PIT fish and AT fish in a similar manner). Fish length was positively correlated with the survival of both PIT and AT fish. Survival was markedly low among the smallest length class (that is, 80 mm to 89 mm) of both PIT and AT subyearling Chinook salmon and the survival of PIT fish was generally greater than that of AT fish.ConclusionsThe lack of a length-specific tag effect suggests that under the conditions used in this study, differences in survival between PIT and AT fish may be due to the process of surgically implanting the transmitter rather than the presence of the transmitter.

A Field Evaluation of an External and Neutrally Buoyant Acoustic Transmitter for Juvenile Salmon: Implications for Estimating Hydroturbine Passage Survival

Turbine-passed fish are exposed to rapid decreases in pressure which can cause barotrauma. The presence of an implanted telemetry tag increases the likelihood of injury or death from exposure to pressure changes, thus potentially biasing studies evaluating survival of turbine-passed fish. Therefore, a neutrally buoyant externally attached tag was developed to eliminate this bias in turbine passage studies. This new tag was designed not to add excess mass in water or take up space in the coelom, having an effective tag burden of zero with the goal of reducing pressure related biases to turbine survival studies. To determine if this new tag affects fish performance or susceptibility to predation, it was evaluated in the field relative to internally implanted acoustic transmitters (JSATS; Juvenile Salmon Acoustic Telemetry System) used widely for survival studies of juvenile salmonids. Survival and travel time through the study reach was compared between fish with either tag type in an area of high predation in the Snake and Columbia rivers, Washington. An additional group of fish affixed with neutrally-buoyant dummy external tags were implanted with passive integrated transponder (PIT) tags and recovered further downstream to assess external tag retention and injury. There were no significant differences in survival to the first detection site, 12 river kilometers (rkm) downstream of release. Travel times were also similar between groups. Conversely, externally-tagged fish had reduced survival (or elevated tag loss) to the second detection site, 65 rkm downstream. In addition, the retention study revealed that tag loss was first observed in fish recaptured approximately 9 days after release. Results suggest that this new tag may be viable for short term (<8 days) single-dam turbine-passage studies and under these situations, may alleviate the turbine passage-related bias encountered when using internal tags, however further research is needed to confirm this.

The effects of high detection probabilities on model selection in paired release-recapture studies in the era of electronic tagging studies

BackgroundAcoustic-tag studies with their high to very high detection rates defy traditional statistical wisdom regarding analysis of tagging studies. Conventional wisdom has been to use a parsimonious model with the fewest parameters that adequately describes the data to estimate survival parameters in release-recapture studies in order to find a reasonable trade-off between precision and accuracy. This quest has generated considerable debate in the statistical community on how to best accomplish this task. Among the debated options are likelihood ratio tests, Bayesian information criterion, Akaike information criterion, and model averaging.ResultsOur Monte Carlo simulation studies of paired release-recapture, acoustic-tag investigations indicate precision is the same if a fully parameterized or a reduced parameter model is used for data analysis if detection probabilities are very high. In addition, the fully parameterized model is robust to heterogeneous survival and detection processes, while a reduced parameter model may be sensitive to misspecification.ConclusionsUse fully parameterized, paired release-recapture models when detection probabilities are very high (≥0.90) to analyze acoustic-tagging data in order to retain both robustness and precision, and without the subjectivity and ambiguity introduced by the choice and application of model selection techniques.

Compliance Monitoring of Underwater Blasting for Rock Removal at Warrior Point, Columbia River Channel Improvement Project, 2009/2010

The U.S. Army Corps of Engineers, Portland District (USACE) conducted the 20-year Columbia River Channel Improvement Project (CRCIP) to deepen the navigation channel between Portland, Oregon, and the Pacific Ocean to allow transit of fully loaded Panamax ships (100 ft wide, 600 to 700 ft long, and draft 45 to 50 ft). In the vicinity of Warrior Point, between river miles (RM) 87 and 88 near St. Helens, Oregon, the USACE conducted underwater blasting and dredging to remove 300,000 yd3 of a basalt rock formation to reach a depth of 44 ft in the Columbia River navigation channel. The purpose of this report is to document methods and results of the compliance monitoring study for the blasting project at Warrior Point in the Columbia River.

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2011

This report presents survival, behavioral, and fish passage results for tagged yearling Chinook salmon and juvenile steelhead as part of a survival study conducted at John Day Dam during spring 2011. This study was designed to evaluate the passage and survival of yearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a paired-release survival model.