Assessing Fish Condition After Passage Through Conventional and Fish-Friendly Turbines Using a Release Recapture Technique

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1 Assessing Fish Condition After Passage Through Conventional and Fish-Friendly Turbines Using a Release Recapture Technique Paul Heisey, Chris Avalos, and Joanne Fulmer Normandeau Associates, Inc. Drumore, PA

2 Objectives The primary purpose of this presentation is to show how the HI-Z Tag recapture technique (balloon tag) can be used to assist in the development of fish friendlier turbines. Four studies will be presented.

3 Background Two principal methods have been utilized to assess post passage condition of turbine passed fish: 1. Tailrace netting 2. HI-Z Tag

4 Tailrace Netting Captures naturally migrating fish. Difficult to differentiate net induced injuries, i.e. descaling, bruising, torn opercula. Feasible at only low turbine discharge. Tailrace fish intrusion. Underestimation of dead/injured fish if net not tight to draft tube exit.

5 HI-Z Tag Recapture Technique Technique allows determination of injury and mortality mechanisms by examination of captured fish directed towards specific passage locations. Methodology used to: Assess condition of fish passing turbines, spillways, sluiceways, and fish bypass structures for approximately 20 years. Determine the rate, type, severity, and probable cause of injuries (100% recapture often attained). Assess turbine designs (including fish friendlier) and turbine operating conditions. HI-Z Tag main limitation at present is that fish are only surface acclimated, thus potential barotrauma effects not assessed.

6 Overview of HI-Z Tag Application Small Fish Two uninflated tags attached with a small stainless steel pin through musculature along the fishes back via modified ear piercing gun. A radio tag is also attached to aid in tracking fish.

7 Overview of HI-Z Tag Application Large Fish Fish restrained in foam lined tube, tags attached using a combination of a cannula and a cable tie. Cannula removed, cable tie and tags remains in fish. Typically 3 to 6 uninflated tags are attached, dependent on fish size.

8 Fish Release-Recapture Tags attached and activated Fish released into evaluation passage site Fish buoyed to surface / recaptured Fish held for 48 h delayed effects

9 Four Case Studies Four studies are presented to show the effects of different turbine features and or the incorporation of fish friendlier features on the condition of turbine passed fish.

10 Bonneville Study Conventional Kaplan vs. Minimum Gap Runner Comparative study conducted from November 1999 through January ,000 juvenile Chinook Salmon (avg. 166 mm) released through Kaplan unit and a new minimum gap runner (MGR) at four power levels. MGR designed to minimize gaps between the blade and hub as well as between blade tip and discharge ring. Both turbine types had a runner diameter of 7.1 m, rotational speed of 75 rpm, and 5 runner blades.

11 Fish release pipe deployment to direct fish towards the hub, mid blade, and blade tip of turbine.

12 Results Fish that passed near the blade tip of the MGR unit had higher survival and lower injury rates than those passing the conventional unit. Depending on power level, absolute survival of blade tip released fish was up to 3% higher for the MGR unit than the conventional unit. Injury rates were up to 3.5% lower for the MGR unit. Survival rates for fish passed toward the hub were similar for both units, 99.4% for the existing unit and 98% for the MGR. Injury rates for hub released fish also similar (0.8% conventional, 1.0% MGR).

13 Results (continued) Closing blade tip gaps beneficial. Generation level no significant effects, but trended higher for units operating beyond peak efficiency. Release pipes deployment indicated that most fish may have passed some distance away from the hub and benefits of MGR not fully evaluated.

14 Applicability For Turbine Assessment Passage towards the hub area just beyond the hub/blade interface was quite benign ( 1% injury rate) at both conventional and MGR. Hydraulic conditions and blade features encountered at these locations need further evaluation.

15 Wanapum Study Conventional Kaplan vs. Advanced Hydro Turbine System Study conducted from February through April Nearly 9,000 juvenile Chinook Salmon (avg. 169 mm) released through Kaplan unit and a new Advanced Hydro Turbine System (AHTS). The AHTS design minimized gaps between the blade and hub and the tip of blade and discharge ring; stay vanes, wicket gates, and draft tube also modified. Both units rotated at 85.7 rpm, had a runner diameter of 7.2 m and operated at a 23.5 m head. The AHTS had one more blade (6) than the conventional unit (5). Fish released through gate slot at 10 and 30 ft below the turbine intake ceiling.

16 Results Survival estimates for the conventional and AHTS fish released 10 ft below the intake ceiling was 97.9 and 98.5%, respectively. Survival of fish released at the 30 ft depth were 97.1% for the conventional unit, and 95.4% for the AHTS. AHTS survival estimates trended higher for the shallow released fish but lower for the deeper released fish. Injury estimates for shallow released fish were 0.8% for the AHTS versus 1.8% for the conventional. Injury estimates for deeper released fish were 3.3% for AHTS and 2.5% for conventional.

17 Projected flow path past the turbine blade for fish released 10 ft below intake ceiling. Effects of hub closure likely not fully evaluated.

18 Projected flow path past the turbine blade for fish released 30 ft below intake ceiling.

19 Applicability For Turbine Assessment Fish passage location very important when evaluating specific locations along turbine blade. An additional blade probably minimized some of the AHTS design benefits.

20 Kelsey Station Study Comparison of existing vs. replacement units Assessed large fish survival/injury rate passed through an existing turbine in 2006 and its replacement in Units essentially the same, fixed propeller blades, new unit had one less blade (5 versus 6). Runner diameter 7.9 m, rotation rate 125 rpm, operational head of 17 m. Leading blade edge was narrower for the new unit. 190 adult walleye (avg. 450 mm), and 183 northern pike (avg. 600 mm) were released near ceiling, middle and bottom of intake.

21 Results Survival estimates for both walleye and northern pike increased with a decrease in the number of turbine blades. Walleye survival rates for the 6 blade and 5 blade units were 80.4 and 87.8%. Northern pike survival rates for the 6 blade and 5 blade units were 65.8 and 75.5%. Injury rates did not decrease with a decrease in blade number. Rates similar (near 32%) for walleye. Five blade unit worse for Northern pike, injury rate 62%; 55% for 6 blade unit.

22 Results (continued) Injury unique to new 5 blade unit Thinner sharper blades suspected cause

23 OLD 6 Bladed Turbine NEW 5 Bladed Turbine Leading edge not as narrow Leading edge very narrow Alden tests indicated importance of thickness and shape of blade edge.

24 Applicability For Turbine Assessment Thickness and shape of leading edge of blade important factor in contributing to injury especially on larger fish.

25 French Hydro Stations Studies The effect of turbine blade number assessed on 581 adult eels (599 mm to 1001 mm) passed through two Kaplan units, Rhine River, France. The two turbines were similar except for blade number. Four Blade Unit, 88 rpm, runner diameter of 6.7 m. Five Blade Unit, 94 rpm, runner diameter of 6.2 m. Both units operated at 15 m head. Eels were released near the ceiling, middle, and near bottom of the turbine intake.

26 Results Survival was substantially higher for the 4 blade unit (92.4%) than for the 5 blade unit (78.6%). Injury rates were 7.4% for 4 blade turbine and 26.5% for 5 blade turbine.

27 Applicability For Turbine Assessment The one additional blade and slightly smaller unit markedly decreased survival and increased the incidence of injuries for eels. Relatively high turbine passage survival may be attainable for eels with improved turbine design.

28 Summary and Further Research Direct injury studies have demonstrated that minimizing gaps between turbine blade and hub and between tip of turbine blade and discharge ring can make turbines fish friendlier. Field evaluation studies to evaluate specific turbine features, need to release fish so they will encounter the modified feature. Reduction in number of blades and increasing distance between blades generally provides the greatest benefits to entrained fish.

29 Summary and Further Research (continued) Specific turbine features/operating conditions that have inflicted minimal injuries should be further evaluated. Recent laboratory studies and direct injury studies indicate that blade shape and thickness, particularly the leading edge, can also markedly affect survival and injury. Additional field tests should be conducted with a range of blade shapes to ascertain which design best minimizes injury while still providing efficient turbine operations.