Passage of Juvenile Chinook Salmon and other Fish Species through Archimedes Lifts and a Hidrostal Pump at Red Bluff, California
Present address: U.S. Bureau of Reclamation, MidPacific-400 168 Ralston Road, Bedford, Kentucky 40068859, USA.
Abstract
Fish were passed through two large Archimedes lifts and a large Hidrostal pump at the U.S. Bureau of Reclamation's experimental pumping plant on the upper Sacramento River, California. Two of the pumps were run concurrently during trials to compare their effects on hatchery-reared juvenile chinook salmon Oncorhynchus tshawytscha. In each trial, control samples were released at pump outfalls, and treatment samples were inserted into the intake of each pump. Fish in samples were collected in downstream holding tanks. In 27 trials comparing the two Archimedes lifts, mean survival for paired control and treatment groups was 98.3–99.0% for both lifts. Effects from pump passage were not detected for either lift at α = 0.05. In 40 trials comparing the Archimedes lifts and Hidrostal pump, mean survival for paired control and treatment groups was 96.5–99.5% for both pump types. Effects of passage through these small pumps were detected: 0.9% for the Archimedes lifts and 2.4% for the Hidrostal pump. To examine their effects on riverine fish, the two Archimedes lifts and the Hidrostal pump were run concurrently for 24 h during 24 trials. The pumps entrained 3,337 juvenile chinook salmon and 2,773 fish of 27 other species. Survival per pump for riverine chinook salmon and the other species taken collectively ranged from 94% to 98%, and among-pump differences were not statistically significant. Postpassage examinations of chinook salmon from experimental trials and entrained riverine fish revealed a very low incidence of potentially debilitating injuries among surviving individuals. Because of these results and supporting data in other studies, this pumping technology is being considered for use at other water diversion sites in California to protect fisheries resources.
Introduction
Intensive physical manipulation of freshwater resources has promoted development of today's modern societies and technologies. Some of these manipulations have had severe effects on fish habitats and populations (National Research Council 1996). In recent decades, major efforts have been made to reduce these effects, particularly those from dams and water intakes for municipal and industrial facilities (Odeh 2000). During 1992–1994, the U.S. Bureau of Reclamation established a research program on large versions of Archimedes lifts and Hidrostal pumps that might safely pass fish while making high-volume deliveries of water for irrigation and other purposes. At that time, limited research suggested that large Archimedes lifts would pass fish safely. Stahle and Jackson (1982) described Hidrostal pump design and reported on its use for rapidly off-loading catches of oceanic fishes without damage to the product. Subsequently, Patrick and Sim (1985), Rodgers and Patrick (1985), and Patrick and McKinley (1987) examined mortality associated with fish passage through small versions of this pump (intake diameters of 15 cm, high impeller revolutions of 400–1,200 revolutions per minute [rpm], and low discharge rates of 0.2 m3/s). Mortalities for American eels Anguilla americana and rainbow trout Oncorhynchus mykiss passed through these Hidrostal pumps were low (<5%) across the range of impeller speeds, and little evidence of sublethal damage was observed. However, yellow perch Perca flavescens and alewife Alosa pseudoharengus were significantly less hardy. These species experienced low mortality at 450 rpm (1–5%), but mortality increased to as much as 29% at rpm ≥600.
Construction of a pumping facility for research on fish passage was completed at the Bureau of Reclamation's Operations and Maintenance Center on the Sacramento River near Red Bluff, California, in 1995. It had two large Archimedes lifts and one large Hidrostal pump. Collections of riverine fish made during construction showed that juvenile chinook salmon Oncorhynchus tshawytscha made up most of fish that were likely to be entrained by operation of the pumps (Johnson and Martin 1997). Because of concern for protection of this species, especially the Sacramento River's endangered winter run, chinook salmon became a target species for this study. The objective of our work was to compare the Archimedes lifts and Hidrostal pump for damage to chinook salmon and other species that passed through them.
Methods
The facility
The face of the intake structure at the Red Bluff Research Pumping Plant on the Sacramento River (391 river kilometers above San Francisco Bay) had a trash rack (Figure 1) with small openings (5 cm) between parallel vertical bars. This construction entrained only small fish. Intake pipes (inner diameter, 1.22 m) behind the trash rack were horizontally aligned with the river bottom and opened into four separate pump-bays. Two identical Archimedes lifts were installed in two of the bays. The lifts were 11.58 m long and 3.05 m in diameter. They had revolving barrels with three fixed internal flights. The lifts operated at 26.5 rpm and delivered water at 2.3–2.8 m3/s. The Hidrostal pump was installed in a third bay. It had an inlet diameter of 0.91 m and a single-vane impeller cast with a rotating conical shroud. It operated at 350–375 rpm and delivered water at 2.3–2.8 m3/s.
Schematic of the Red Bluff Research Pumping Plant, Sacramento River, California. Archimedes lifts were in pump bays 1 and 2. The Hidrostal pump was in bay 3, and bay 4 was empty. Dotted lines indicate underground portions of water intakes, the conveyance system for irrigation water, and the fish bypasses
Discharge from the lifts and Hidrostal pump fell into separate concrete sluiceways, then moved downstream where a pair of vertical, stainless steel wedgewire screens (4.0-mm bars, 2.4-mm gap) passed 89–90% of pumped water to an adjacent irrigation canal. Each screen was equipped with a vertical brush that moved back and forth over its length to prevent accumulation of debris. About 10% of pumped water, with its debris load, moved downstream beyond each set of screens and entered a concrete channel of the fish-bypass system that led to the Sacramento River (Figure 1).
Fish that passed through pumps and beyond vertical screens could be diverted to holding tanks on each pump's bypass. Rectangular dewatering ramps (Figure 1), hinged at the downstream end, were dropped into bypass channels to intercept their flow. The face of each ramp was covered with stainless steel wedgewire screen (4.0-mm bars, 2.4-mm gap). Fish and debris moved with water along a screen's surface and entered a stainless steel channel leading to a pair of holding tanks that were lined with nylon nets (3.2–4.7-mm mesh) to prevent fish loss in overflow.
Passage of hatchery-reared chinook salmon
Survival and the frequency of sublethal damage were compared between paired releases of samples of juvenile chinook salmon. Two experiments were conducted for between-pump effects. Two Archimedes lifts were run simultaneously during 27 trials for one experiment; the Hidrostal pump and one randomly selected lift were run simultaneously for 40 trials in the other. During each trial, two control samples were released in sluiceways downstream of pump outfalls (Figures 2, 3). Two treatment samples were released into fish insertion standpipes, and then crowded downward into pump intakes. Fish in both types of samples were collected in holding tanks (Figure 1). With this approach, each trial had two paired tests of pump passage effect (control versus treatment), a paired test of outfall to holding tank effect (control versus control), and a paired test of pump intake to holding tank effect (treatment versus treatment). Individuals belonging to control and treatment samples were identified by markings with Bismarck brown-Y (Mundie and Taber 1983) or small clips on selected fins. The average number of fish per sample was 31 (range, 20–32). Chinook salmon used in trials were from 25 cohorts of several hundred juveniles each, supplied by the U.S. Fish and Wildlife Service at Coleman National Fish Hatchery in Anderson, California. The average fork lengths of fish in a cohort ranged from 34 (SD, 0.9) to 74 mm (SD, 5.5).
Cut-away perspective for Archimedes lifts in bays 1 and 2 of the Red Bluff Research Pumping Plant, Sacramento River, California. During operations, entrained fish were carried upward in the lifts and dropped into sluiceways that led downstream to the vertical screens shown in Figure 1
Cut-away perspective for the Hidrostal pump in bay 3 of the Red Bluff Research Pumping Plant, Sacramento River, California. After passing through the pump, entrained fish were carried upward and discharged into a sluiceway that led downstream to the vertical screens shown in Figure 1
Because most chinook salmon (73–81%) entrained from the Sacramento River entered holding tanks at night (McNabb et al. 1998), trials were conducted in darkness in the period between sundown and midnight. Control and treatment samples were moved to the pumping plant in 19-L clear, plastic carboys modified to release fish at the water surface. Carboys contained 7–9 L of river water with salt (5–7 g/L) and Kordon's PolyAqua (0.13 mL/L) to reduce injury and stress (Nikinmaa et al. 1983; Summerfelt and Smith 1990; Wedemeyer 1992). Time elapsed during release of the two control and two treatment samples used in each trial was about 1 h. Holding tanks were continuously tended during releases and for 2–3 h thereafter. Dip nets were used to recover the chinook salmon. Fish belonging to control and treatment samples were identified by their markings. Dead fish per sample were enumerated, and live fish were held in river water for 96 h to record delayed mortalities. Survival for each sample was the percentage, in a given holding tank, of the total number of surviving fish recovered at the end of the 96-h postpassage period. The Wilcoxon's signed rank test (Steel et al. 1997) was used to determine statistical significance (α = 0.05) of the paired comparisons.
During some trials, less than 100% of the chinook salmon in a sample were recovered in a holding tank. Studies conducted specifically to find missing fish showed that they were not dead. Dead individuals were swept promptly into holding tanks by currents, and missing fish lingered in the vicinity of pump outfalls or around vertical screens for periods longer than the 96-h test periods. They then moved downstream and out of the pumping plant when dewatering ramps were raised on days between trials (McNabb et al. 1998). Overall, 3.5% of 4,227 chinook salmon used in control samples were missing, and 4.2% of 4,192 fish were missing from treatment samples.
Descaling and other injuries were recorded for all dead fish recovered. Also, two live fish, selected without known bias from each control and treatment sample just before release in the pumping plant, were examined for sublethal injuries due to pretrial handling. Two live fish taken haphazardly from each control and treatment sample immediately after arrival in holding tanks were also examined for injuries associated with pump passage. Examinations were made at magnifications of 7–10×. Descaled percentages in three zones (Kostecki et al. 1987) on each side of an affected fish were combined to yield an overall estimate of descaled percentage. The location and type of other injuries (bruises, wounds, erosion, etc.) to the head, eyes, body, or fins were recorded. Data for live fish were pooled to estimate frequencies of injured individuals. Background descaling on fish from the hatchery (≤5% of scaled surface) and erosion along edges of opercula and fins due to confinement in raceways were discounted in these assessments. Chi-square analysis (Steel et al. 1997) was used to test for pump passage effects (α = 0.05) under the null hypotheses that the distributions of three injury categories (noninjured, descaled, and other injuries) between live postpassage control and treatment fish were equal.
Temperature, dissolved oxygen, total gas saturation, turbidity, and debris were measured during the paired comparison trials. Estimates of debris that entered holding tanks were made using volumetric measures of water displacement (cm3) per hour. Regression analysis (Sokal and Rohlf 1995) was used to assess the relationship between rate of debris accumulation and survival of chinook salmon.
Passage of entrained fish
On 24 occasions, the two Archimedes lifts and Hidrostal pump were operated simultaneously to entrain riverine fishes. Each sampling event began at sunrise by lowering dewatering ramps (Figure 1). Fish were collected from holding tanks on each pump's bypass at the following sunset and sunrise. Water temperature, dissolved oxygen, total gas saturation, and turbidity were recorded when fish were collected. Fish were enumerated by species and numbers of live and dead were noted. Fork-length was measured on chinook salmon, and total length on other species. Debris was removed from each tank at times when fish were collected, and volumes (cm3) that accumulated during 24 h were measured. Regression analysis (Sokal and Rohlf 1995) was used to assess the relationship between volume of debris and survival of entrained chinook salmon. The Kruskal–Wallis test was used to detect significant differences (α = 0.05) in survival among pumps for chinook salmon and fish of other species.
Fish that survived entrainment were examined to determine the frequency of those with sublethal injuries. Notations were made for the types of injuries on head, eyes, skin, or fins. When large numbers of fish were entrained, measurements of length and inspections for injuries were limited to 100 haphazardly selected chinook salmon and 30 fish of other species per pump. Larval fish less than 30 mm total length (prickly sculpin Cottus asper and Sacramento sucker Catostomus occidentalis) were frequently entrained, but assessments of their survival and injury were not included in this study.
Results
Paired Trials
In trials comparing Archimedes 1 and Archimedes 2, mean survival for all control groups and treatment groups was 98% or more (Table 1). Paired control and treatment groups did not differ significantly for Archimedes 1 or Archimedes 2. There were no pump passage effects. Differences between paired control groups or paired treatment groups were not significant for either lift. In trials to compare Archimedes lifts and the Hidrostal pump, survival in all control and treatment groups was also high, but Archimedes control versus Archimedes treatment groups showed a significant pump passage effect (P = 0.024; Table 2). This resulted from very high survival for the control group in Table 2 (99.5%) compared with control groups in Table 1, whereas treatment group survival in Table 2 (98.6%) was nearly the same as survival for treatment groups in Table 1. A highly significant pump passage effect is indicated in Table 2 for Hidrostal control versus treatment. A significant difference between the lifts and Hidrostal pump is indicated by the lack of a significant difference between paired control groups (P = 0.107) but significantly higher survival (P = 0.020) for the lift treatment groups (Table 2).
Our work was designed to produce two particular subsets of the paired-release survival data. One dealt with the frequency of fish that were dead on arrival in holding tanks (immediate mortality) and the frequency of fish that were dead at 96 h postpassage (delayed mortality, which estimated the potential for passage-related mortalities). Survival during the 96-h holding period for all pairs of the control and treatment groups shown in Table 1 and Table 2 was very high (means 99.0–99.6%). The Wilcoxon's signed rank test (Steel et al. 1997) showed no significant difference for any of the pairs of control and treatment groups at 96 h Thus, significant pump passage effects reported in this study (Table 2) were due to immediate rather than delayed mortalities. Immediate survival was significantly higher for the control group than for the treatment group for the Archimedes lifts (P = 0.018) and for the Hidrostal pump (P = 0.001; Table 2).
For Archimedes lifts, pump passage effects were not observed for paired releases of control and treatment groups of small (34–42 mm fork-length) or large juvenile chinook salmon (58–74 mm fork-length; Table 3). In contrast, survival for the Hidrostal pump control groups was significantly higher than for treatment groups for small (P = 0.041) and large (P = 0.016) juveniles.
The frequency of descaling and other injuries to live fish taken at different junctures during the trial process are summarized in Table 4. Prepassage fish had minor injuries resulting from handling while marking or otherwise preparing samples for release in the pumping plant. Frequency of prepassage fish with descaling was low, ranging from 0.5% to 0.6%. The amount of descaling on the affected individuals varied from 8% to 23%, and 2.5–4.3% of prepassage fish had other minor injuries, most often small bruises. The frequency of injured fish in control and treatment samples increased with passage through the pumping plant. However, no significant pump-related effects were detected because frequencies of injured individuals were not significantly different between postpassage control and postpassage treatment fish used with the Archimedes lifts (P = 0.312) or the Hidrostal pump (P = 0.784). Descaling on postpassage control and treatment fish was similar to that of prepassage fish (8–35%). Minor head and skin injuries predominated the other injuries category for postpassage control and postpassage treatment fish. Damaged fins were rare. Frequencies of injured fish did not differ significantly between the Archimedes lifts and Hidrostal pump for either prepassage fish (P = 0.610), postpassage control fish (P = 0.432), or postpassage treatment fish (P = 0.264).
Good water quality occurred during paired trials. Temperatures ranged from a low of 8.4°C during trials conducted in winter to 14.0°C during trials in summer. The range for dissolved oxygen concentration was 8.2–11.9 mg/L. The range for total gas saturation was 99.0–105.6%. Turbidity ranged from 3.8–38.1 nephelometric turbidity units. Debris consisted of small sticks, deciduous leaves, aquatic macrophytes and filamentous algae. The Archimedes lifts and Hidrostal pump entrained water at normal operating rates 2.3–2.8 m3/s (9 × 1012 cm3/h), and debris accumulated in holding tanks at rates of 4–706 cm3/h. As a consequence, debris concentrations that accompanied fish through pumps were low, about 1 cm3 of debris per 10–100 m3 of water. Survival of experimental fish for trials with all three pumps (N = 35) was not significantly related to debris accumulation (P = 0.473, r2 < 0.01).
Entrained Fish
A total of 6,110 fish of 27 species were entrained from the Sacramento River and examined for damage. Entrained fish were generally small; only 1.7% were greater than 200 mm in length. Juvenile chinook salmon made up 55% of the total. Most of the chinook salmon (86%) were small (28–39 mm fork length). Prickly sculpin, lamprey ammocetes Lampetra spp., Sacramento sucker, and Sacramento pikeminnow Ptychocheilus grandis were the next most common species, composing 38% of the fish entrained by the pumps. Mean survival of chinook salmon entrained by all pumps ranged from 94% to 98%, and mean survival for fish of all other species combined ranged from 94% to 95% (Table 5). Survival did not differ significantly among pumps for either chinook salmon (P = 0.875) or the other species combined (P = 0.84). Percentages of the surviving chinook salmon with injuries were low: 2.2, 1.5, and 3.0% for Archimedes 1, Archimedes 2, and the Hidrostal pump, respectively. Percentages of other fish with sublethal injuries were 3.8, 3.2, and 4.2 for Archimedes 1, Archimedes 2, and the Hidrostal pump, respectively. The most common injuries were bruises, small open wounds, and abrasions on body surfaces. Damage to the head and fins was rare.
During the entrainment assessment, water temperatures, dissolved oxygen concentrations, total gas saturations, and turbidities were all within ranges reported above for the trials with hatchery chinook salmon. However, unlike the hatchery fish that were removed from holding tanks upon their arrival, entrained riverine fish were not removed and were exposed to damage from debris that accumulated until the holding tanks were checked at sunset and sunrise. Survival of entrained chinook salmon was negatively related to volumes of debris in tanks (N = 72, P = 0.002), but the amount of variability in survival explained by the regression relationship was small (r2 = 0.11).
Discussion
Our investigation shows that large Archimedes lifts and Hidrostal pumps have the potential to pass fish without inflicting biologically significant damage. Among paired releases of juvenile chinook salmon, 99% of all control fish and 98% of all treatment fish survived passage to the holding tanks. Microscopic examination of the dead showed that 25% of the control fish and 89% of treatment fish had open, obviously mortal wounds on the head or body. Cada (2001) suggested that wounds like these were “strike” injuries caused by head-first collisions with internal structures of pumps, or “grinding” injuries caused by squeezing the body through narrow gaps between fixed and moving parts of pumps. In our study, grinding injuries in control and treatment fish could also have been caused by temporary entrapment with brushes that moved along the screens downstream of pumps. Of the dead, 57% of control fish and 8% of treatment fish had little or no visible external damage. These may have died from injury to internal organs sustained during passage through the pumping plant or during handling. Stress alone was unlikely to have caused these mortalities. Weber et al. (2002) reported on plasma cortisol levels and behavioral responses of juvenile chinook salmon that passed through the Archimedes lifts and Hidrostal pump at Red Bluff and found no evidence of excessive stress.
Patrick and Sim (1985), Rodgers and Patrick (1985), Patrick and McKinley (1987), and Helfrich et al. (2001) reported on the passage of 31 species of fish through small (0.15–0.41-m-diameter), low-output (0.2–0.4 m3/s) Hidrostal pumps. Most of the fish, including chinook salmon, were small (17–218 mm length). Some (e.g., threadfin shad Dorosoma petenense, American shad Alosa sapidissima and delta smelt Hypomesus transpacificus) were relatively fragile and sensitive to handling. Survival of all species, large, small, or fragile, was high (95–100%) at impeller speeds of 600 rpm or less. Our work at Red Bluff showed that a large Hidrostal pump operating at 350–375 rpm and delivering water at 2.3–2.8 m3/s could also pass a variety of fish species at high rates of survival.
As far as we are aware, data on mortalities and injuries among fish passed by Archimedes lifts has not appeared in the formal literature. In our paired experimental releases of control and treatment groups, the Archimedes lifts caused slightly less mortality than the Hidrostal pump. Johnson and Martin (1997) found that most juvenile chinook salmon in the Sacramento River near the pumping plant were small individuals (31–41 mm fork length), and Fisher (1994) observed that young chinook salmon emerged from redds on spawning grounds in the upper river at an average fork-length of about 34 mm. Our Archimedes lift survival data for paired releases of control and treatment groups, when separated into small (34–42 mm) and larger size-classes, showed no statistically significant passage effects. For the Hidrostal pump, statistically significant passage effects were detected for both size-classes, but the numbers affected were biologically small (2–3% mortality). For trials of entraining riverine fishes, survival differences between the Archimedes lifts and Hidrostal pump were not significant. Both Archimedes lifts and the Hidrostal pump had little or no effect on frequencies of surviving experimental chinook salmon or riverine fishes that had passage-related sublethal descaling or other sublethal injuries. Taken collectively, our data and data from the literature show that Archimedes lifts and Hidrostal pumps can both pass a variety of fishes without inflicting biologically significant damage. Therefore, engineering technology using the large pumps described in this paper is being considered for application at other water diversion sites in California to protect fisheries resources (Helfrich et al. 2001).
Acknowledgments
We would like to thank M. Stodolski, R. Corwin, E. Weber, C. Knud-Hansen, T. Batterson, L. Helfrich, and J. Medina for technical assistance and the Operations and Maintenance Staff of the U.S. Bureau of Reclamation at Red Bluff for maintaining physical features of the pumping plant operating in a fish-friendly mode throughout the years of this work. Student aids from California State University-Chico and Shasta Community College helped with trials. R. Shudes and the U.S. Fish and Wildlife Service staff at Coleman National Fish Hatchery supplied juvenile chinook salmon and advised on maintaining robust and disease-free cohorts. Administrative support was given by D. Weigmann. On-site assistance from her staff from U.S. Bureau of Reclamation's Denver Technical Service Center was appreciated. Comments of two anonymous reviewers greatly improved the text. Editorial contributions of Alex Wertheimer were particularly helpful. A major portion of the funding for this work was provided by U.S. Bureau of Reclamation's Mid-Pacific Region, supplemented by its Research and Technology Development Program, Study Number AECO-98.016 (WATR), and from appropriations received under the Central Valley Project Improvement Act, Public Law 102–575, Title 34.
