# 2230 cO 

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# II v oc.l.ld; 

# , ,
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### W~lDUFE 

# RECEIVED
The Vernon Bypass Fishtube: Evaluation of Survival and Inj Dries of 

# Atlantic Salmon Smolts Allr.. 19 1998 ENGINEERING - REGION 5 HADLEY. MA



## Prepared for: 

# New England Power Company 25 Research Drive 

# Westborough, MA 01582

Prepared By: 

# Normandeau Associates, Inco 

# Brattleboro, VT
Normandeau Project No. 15030. 003



## May 1996 

# NORMANDEAU ASSOCtME86 ENVIRONMENTAL CONSULTANTS

## The Vernon Bypass Fishtube: 

# Evaluation of Survival



# and Injuries of Atlantic Salmon Smolts

Prepared for: 

# New England Power Company 25 Research Drive 

# Westborough, MA 01582

Prepared By: 

# ormandeau Associates, Inc. Brattleboro, VT
Normandeau Project No. 15030. 003



## May 1996

### CONTENTS Page



# ........... . . . . .



## . . . ii



# ...............

iii 

# . . . ..

List of Tables . List of Figures List of Appendices 

# .......... 

# ................ . . . . .



### Executive Summary 

# ..............................................

ES

### 1.0 INTRODUCTION 

## 1.1 Background.... . . . . . . . . . . . . . . . 2 Vernon 

### Hydroelectric Project 

### Description. . . . . .

. . . . . 1 . . . 1 . . . . . . . 

# .................... . . . . . 

## . . .

. . . 3 . 3 

# ., .. . . . ... . .

0 MATERIALS and METHODS 

### 1 Study Design 

## . . . . . . . . .

2 Source and Maintenance of Salmon Smolts . 3 Tagging . . . . . .

4 Fish Introduction 

### 2.5 Fish Recapture 

## . . . . . . . . . . . .

6 Classification of Recaptured 

## Fish. . . . . . . . . . . . 

# 7DataAnalysis................... . . . . . . . . . . . 

### . . . . . 

### . . . . . . 

### . . . . . . . . . . . . . . . . 

### . . . . . . 

## . . . . . . . . . . . . . . . . . . . . . . .

. . . 8 . . . 8 . . . . . . . 8 

## . . . . . . .

. . . . . . . 9 

### 0 RESULTS

1 Testing Schedule and Conditions, and Smolt Sizes 2 Fish 

### Recapture 

## 3 Survival.. 3.4 Injuries 

## . . . . . . . . . . . . . . . . . . . 

## " . . . . . . . . . . . .
. . . . . . . . . . . 

### . . . . . 

### . . . . . . 

## . . . . . . . . . 

## . . . . . . . .

0 DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

## . . . . . . . . . . . . . . .

0 LITERATURE CITED 

## . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' . . . ' 

## . . . . . . . .

### Table 1. liST OF 

### TABLES Page Frequency tabulation by group and classification of smolts, and 

### estimates 

### of percent survival and percent uninjured adjusted for controls during Vemon fishtube survival injury study, May 1995. . . . 

## . . . . . . . . . . . . . . . . . . . . .

.. 14

### Figure 1.

Figure 2. 

### Figure 3. Figure 4. Figure 5. LIST OF FIGURES Page

Map of the Connecticut River showing the location of Vernon Project. 

# .......

PlanviewofVemonProject................................... Schematic cross section of Vemon Project bypass fishtube. . . . . . . . . . . . . . ..



### Typical induction system used to introduce treatment and control Atlantic 

# salmonsmolts............................................ Frequency distribution of elapsed times between release and recapture times for control and treatment smolts during the Vernon bypass fishtube evaluation study, May 1995. .........................................



### illliST OF 

### APPENDICES 

### Page

Appendix A. 

### Derivation of precision and sample size. . . 

## . . . . . . . . . . . . . . . . . . . . . . . ..

Appendix Bl. Short-term bypass fishtube survival data on treatment and control fish. " 

# '"

Appendix B2. 

### Condition codes assigned to fish and Turb' 

### N Tags during a fish passage



### survivalstudy. 5. ......................................... AppendixC. SurvivalModeIOutput.......................................

### EXECUTIVE SUMMARY



### New England Power Company sponsored a study to evaluate the survival and injuries of Atlantic salmon smolts introduced into the bypass fishtube at the Vernon Dam on the Connecticut River. The 

### study, utilizing the HI- Z Turb' 

### N Tag recapture technique 

### , was conducted in May 1995 at water temperatures between 16 - 17. 50 C. The 

### discharge through the fisbtube was 40 cis throughout 

### the testing period. Turbine units discharge during the 15 hours of treatment and control fish 

### introductions ranged from 1 

### 795 cfs to 10, 235 cis. Turbine discharge during 13 of 

### the 15 hours was greater than 9 

### 000 cis. 

### Fish for the study were obtained from the USFWS, White River National Fish Hatchery. The mean lengths for treatment and control groups were 156 mm and 149 mm, respectively. Seventy-

### five 

### salmon smolts were passed through the fishtube and 25 smolts served as controls, and were released 

### directly into the tailrace. 

### The survival estimate for the treatment group is based on measures of survival and injury relative to a set of control group specimens. The 

### estimated short-term (1 h) survival of smolts passed 

### through the fistube was 93. 

### 33%. All fish placed in holding, to evaluate 

### long-term survival (48 h), 

### survived the 48 hour period, thus the long-term survival was also 93. 

## 33%. Passage-related injuries to 

### recaptured fish were few and minor. Only two of the 70 (2. 9 %) recaptured treatment group fish exhibited injuries. The 

### observed injuries were scale loss of approximately 10 % and 20% respectively, to the two smolts; one control group smolt 

### was classified as injured. The injuries to the control fish were caused by a smallmouth bass attempting to consume the smolt just as the recovery


### ES-

### crew was netting the smolt from the tailrace. 

### Overall observations during this study included high estimated survival and low observed injury rate to smolts passing 

### through the Vernon fishtube. High and similar recapture rates for 

### treatment (~93%) and control (100%) groups , and high control group survival (100%) provide for a 

### reliable estimate of smolt survival after passage through the fishtube. The fishtube survival estimate was slightly lower

### , but similar to salmon smolt survival 

### estimates from the ice-log sluice at Bellows Falls and Wilder. The slightly lower estimate is due in part to the conservative 

### classification of non-recaptured fish as " dead" . Three of the 

### five nonrecaptured smolts were classified as " 

### unknown 

### " (Le. no tags or radio signal were ever recaptured/detected). Given the high passage 

### survival and low observed injury rate , modifications to 

### the fishtube should not be warranted. However

### , we offer the following recommendations:



### Debris that could lodge in the fishtube should be excluded from entering the tube or removed if lodged in the fishtube; 

### Operate Units 9 and 10 during the peak smolt emigration period , when river flow 

### conditions permit , to minimi7. 

### e predation.



### ES-

### INTRODUCTION

BaCkground During 1994 

### , New England Power Company (NEP) completed the most recent phase of construction for downstream guidance and passage of emigrating anadromous fish at the Vernon and Bellows Falls projects on the Connecticut River. 

### Specific provisions in this phase included the 

### engineering design, hydraulic modelling, and construction of a louvered guidance structure at Vernon design and modification of a fish ladder attraction water supply pipe (fishtube) to pass emigrating fish 

### at Vernon , and a concrete barrier guidance structure in the Bellows Falls intake canal. Effectiveness 

### studies of the guidance structures at Vernon (NAI 1995a) and Bellows Falls (NAI 1995b), and of the 

### fishtube at Vernon were conducted during spring 1995. This document is a report of the
effectiveness of the Vernon fishtube to safely pass emigrating Atlantic salmon (Salmo salar) 

### smolts. The objective was to conduct a controlled experiment to reliably evaluate the injuries to, and survival 

### of Atlantic salmon smolts passed through the fishtube. 1.0 1.1

1.2 Vernon Hydroelectric Project Description 

### Vernon Dam is located on the Connecticut River at river mile 141.9 in the towns of Vernon 

### Vermont and Hinsdale, New Hampshire (Fig. 1). The dam is a concrete gravity type with a total length of 956 ft. 

### A powerhouse and six tainter spill gates are incorporated in the structure. 

### It was 

### completed and began operation in 1909 with eight turbine units. 

### The station (Fig. 2) is operated as a run-of-

### the-river facility. The powerhouse includes eight 

### operational turbine generating units that have a total rated capability of 24. 

### 39 MW. Six units (Units 1-4 

### , 9 , and 10) are siIigle runner Francis type. Units 1-4 have a maximum discharge of 1 280 cubic 

### feet per second (cfs) each; Units 9 and 10 have a maximum discharge of 1 834 cis each. Units 6 

### and 7 are double and triple runner Francis, respectively, each with a maximum. discharge of 978 cis. 

### Units 5 and 8 were recently retired (1994 and 1992 

### , respectively) (E. Brissette, personal 

### communication). NEP designed, and intended to install in 1994

### , two new units that would have 

### replaced four of the original eight units. Based on economic and power need evaluations, the 

### installation of two new units has been indefinitely postponed (R. DeHart, personal communication). Units 1-4 

### , 6, and 7 have nameplate rated electrical output capacity of 2. 

### 5 MW each; Units 9 and 10 are rated at 4. 

### 2 MW each. Normal operating head is 34 ft. The constrUction of fish passage devices at Vernon has occurred over approximately 15 years.

### Vernon was the location of the first modern upstream passage fish ladder within the New England



### Power Company service area (Fig. 2). The facility went into operation in 1981. Construction of 

### downstream passage facilities began in 1990 with the installation of the fishpipe (Fig. 2). 

### The 

### fishpipe measures approximately 82.5 ft in length, and passes through the powerhouse between units 4 

## and 5. It is surface fed and is intended to facilitate 

### downstream passage of fish from the forebay to the tailrace. The fishpipe is 4 ft high 

### throughout its length and measures 7. 

### 6 ft wide at the upstream 

### end and tapers to approximately 2. 6 ft wide at the downstream end. 

### At normal pond elevation

### , the 

### sill of the fishpipe is 10 ft below the water surface. Flow through the 

### open pipe is 350 cis. 

### In 1994 , construction was completed on a louvered guidance boom and a second bypass route 

### known as the fishtube (Fig. 2). The louvered guidance boom was designed to guide emigrating 

### anadromous fish toward the fishpipe (see NAI 1995a for details on the design and operation of the 

### louvered guidance boom). An existing conduit that formerly supplied attraction flow for the fish ladder collection gallery was modified to be used as the fishtube (Fig. 3). 

### The fishtube was designed to pass fish that were not guided by the louver array. 

### A surface fed entrance is located in the western 

### forebay wall of the Station , approximately 25 ft upstream of the Unit 10 trashrack. 

### The entrance 

### measures 8 ft high by 3 ft wide and at normal pond elevation the bottom sill is approximately 6 ft under water. Approximately 4 ft from the 

### lower sill of the entrance the passage diameter tapers from 

### 4 ft to 2 ft, extends through the powerhouse and discharges on the downstream side of the fish ladder collection channel into the tailrace. 

### The discharge through the fishtube is approximately 40 cis. 

### 0 MATERIALS AND METHODS 1 Study Design The evaluation of survival and injuries of Atlantic 

### salmon smolts passed through the fishtube 

### was conducted by utilizing the ID-

### Z Turb, N Tag recapture methodology (Heisey et al. 1992). 

### The 

### resulting estimates were based on measures of survival and injury relative to a set of control group specimens. This approach 

### permitted the isolation of direct effects due to passage through the fishtube. The design and analyses of 

### data followed theory and protocol for the single recapture history design described in Burnham et al. (1987) and Mathur et al. (1994 , 1995b). 

### A total of 100 Atlantic salmon smolts was utilized. Seventy-five smolts were passed through 

### the fishtube and 25 smolts served as controls, and were released directly into the tailrace. This
allocation of sample groups was expected to provide a precision of 

### 10 at ex = 0. 10 on the

### survival estimate given the following assumptions:

. estimated fishtube survival 

## = 0. 95; . estimated control fish 

### survival = 0. 99; and . estimated recapture of treatment and control 

### fish = 0. 99. 

### These parameter estimates were based on previous experience of Normandeau Associates with 

### the HI-

### Z Turb' N Tag (e. 

### g. Mathur et al. 1994 , 1995a

### , b; NAI 1995c; RMC and Skalski 1994a , b).
Given these parameter values, and the desired precision of 

### 10 at ex = 0. , the required sample 

### size was 23 individuals per group (see Appendix A for an explanation of sample size determination). 

### Survival and injuries of the smolts passed through the fishtube were compared to those of the 

### controls to ascertain the degree 

### , if any, of harm incurred to smolts which utilize the fishtube for passage. 

### 2.2 Source and Maintenance of Salmon Smolts 

### Hatchery reared Atlantic salmon smolts were obtained from the USFWS , White River 

### National Fish Hatchery. Smolts were chosen at random from those available for use at the hatchery. 

### Approximately 125 smolts were held in one circular fiberglass 

### holding tank set up on the fish ladder exit structure at Vernon Station. The tank 

### measured 6 ft in diameter and 2. 5 ft deep. Water was 

### continually supplied by pumps submerged in the forebay. The pool was covered to prevent fish 

### escapement, predator access, and excessive solar heat gain. Periodic measurements of water 

### temperature and dissolved oxygen were made to monitor holding conditions. 

### 2.3 Tagging Smolts were netted from the holding tank and placed in an anesthetic bath. 

### Typically, three 

### or four fish were anesthetized simultaneoUsly in a bath of MS-

### 222 at a calculated concentration of 

### between 50 and 75 mgll prior to tag attachment. To avoid 

### excessive temperature rise in the 

### anesthetic bath, the tub containing the anesthetic was kept inside a second , larger flow-through tub 

### which was continually supplied with ambient river water. The anesthetic bath was periodically 

### replaced with fresh water and anesthetic as necessary. 

### Once the fish were sedated, smolt total length was measured and the tags were attached.

### Each fish was fitted with two HI- Z Turb, 

### N Tags. The primary 

### tag was attached through the



### musculature below the dorsal fin. A second tag was attached through the musculature below the adipose fin. 

### A radio tag was attached in combination with the primary Turb' N Tag. The 

### radio tag 

### facilitates more rapid recovery by permitting the recovery crew to get very near the position that the balloon tagged fish are expected to surface.

Prior to release 

### , fish were allowed to recover from the anesthetic for at least 20 minutes in a 

### covered 20 gal flow-through tub supplied with ambient river water. 

### Fully recovered actively 

### swimming tagged fish were individually placed into the induction system holding tub (Fig. 4), tags 

### were activated by injecting a catalyst, then the fish was released. Tagged fish that appeared lethargic 

### were removed from the test and replaced with new fish. All procedures for handling, tagging, release , and recapture of controls and treatment fish were identical. 

### Fish Introduction The induction apparatus delivery hose was deployed such that tagged fish were introduced to 

### the fishtube at a point of commitment. The same induction apparatus was placed on the powerhouse 

### lower gallery for control fish releases. The delivery hose was lowered to the tishtube exit such that 

### both groups (treatment and control) of fish entered the tailrace at similar depths. Recapture crews 

### were notified via two-way radio immediately upon release of an individual smolt. FISh Recapture 

### Two boat crews were available to retrieve treatment and control groups smolts from the tailrace. Boat 

### crews were notified of the radio tag frequency of each fish prior to , and upon release. 

### No particular crew was assigned to retrieve either control or treatment group fish. Only crew 

### members trained in fish handling were employed to retrieve tagged fish. 

### Radio signals were received on a 5 element Yagi antenna coupled to an Advanced Telemetry 

### Systems, Inc. receiver. The radio signal transmission enabled boat crews to follow the movement of 

### each fish upon entry into the tailrace and position the boat for quick retrieval when the Turb' N Tag 

### buoyed the fish to the surface. A fish with an active radio tag that failed to surface was actively tracked for 30 minutes, and then periodically thereafter

### , to determine if the tagged fish displayed 

### movement patterns typical of emigrating smolts or those of a predator that had consumed a study 

### specimen.

### Buoyed fish were retrieved from the tailwaters and placed into an on-board holding facility.



### The tags were removed using specialized pliers and each fish was thoroughly 

## examined. Recaptured 

### fish were immediately taken to an in-

### river net pen located in a calm area, and transferred to an onshore holding pool at day's end for assessment of long-term (48 h) effects. 

### Treatment and control 

### groups fish were held in separate but identical holding pools set up on the lower deck. All pools 

### were continuously supplied with ambient river water and covered to prevent fish escapement , potential 

### predation , and excessive solar heat gain. 

### All control group smolts, and 30 treatment fish were 

### released on day 1 of testing; the remainin

### g treatment fish were released on day 2. Classification of Recaptured Fish 

### , Recapture data were coded to describe the short-term (~ 1 

### h) effects of passage through the
fishtube as follows: (1) 

### dead or 

### alive when 

### recaptured and up to 1 h from release; (2) fish 

### not Dhysically recaptured 

### but the Turb' 

### N Tag(s) and/or radio tag were recovered, classified as se~aration; (3) 

### non-recaptured fish with a transmittini! radio tai! 

### was assigned a status based on movement pattern of the radio tag. These fish were assigned a status 

### short-term mortality 

### if the tag
remained stationary, 

### predation 

### if movement patterns were typical of predatory fish (Le. , rapid 

### movements throughout the tailrace , movement into areas of strong current); and (4) when 

### nothini! was 

### found the fish was classified as 

### unknown

7 Data 

### Analysis 

### Fishtube passage survival rates were estimated using paired release-recapture methods (Ricker 

### 1975; Burnham et al. 1987). Unlike earlier investigations , however

### , recaptures of both alive and 

### dead fish are possible with the ffi-

### Z tag-recapture technique (Heisey et al. 1992). Thus , parameters 

### associated with both alive and dead fish can be incorporated into the construction of a statistical model. This, along with 

### high recapture prob8bilities , can be used to precisely estimate fishtube 

### passage survival rates (Mathur et al. 1995b). Survival calculations are based only on fish categorized as alive.

### The following terms are used in the equations and likelihood functions that follow. 

### Rc = Number of control fish released, 

# R.r = Number of treatment fish released in the fishtube 

# a., = Number of control fish recaptured alive 

# d" = Number of control fish recaptured dead, 

# ar = Number of treatment fish recaptured alive 

# ~ =

Number of treatment fish recaptured dead, 

# S = Probability fish survive from the release point of the controls to recapture P A = 

### Probability an alive, fish is recaptured, 

### Po = Probability a dead fish is recaptured 

### Probability a treatment fish survives to recapture point (Le., fishtube passage survival), 

## ~ =

Fishtube-related mortality. 

### The joint likelihood for the fishtube-related mortality (Skalski 1992) is as follows:



# L (S , T 

# , P

A, PD 

## c, R~ a 

# c' d c, a 

## T' d (SP )a 

# ( (l-S)P- e (l- SP 

# (l-S)P- ' R.: -a 

### e - 

# JJI J)I c' c


## (STP ) aT ((



### ST)PD) T (l-

## STP -(



### ST)pD). T' T 

### The likelihood model is based on the following 

### assumptions: (a) the fate of each fish was independent; (b) the control and treatment fish came from the same population of inference and 

### shared the same natural survival probability, S; (c) all alive fish had the same probability, PA, of 

### recapture; (d) all dead fish had the same probability, Po, of recapture; and (e) fishtube passage
survival (r) 

### and natural survival (S) to the recapture point were independent.

### The above likelihood model has four parameters (P A, PD, S, T) and four 

### minimum 

### sufficient

statistics (3", d

## c, ar, dr). The estimators associated with the above likelihood model are: 

# A aT

RT 

## e a e - 

### T a e a T - 

### T a 

# d~e

R~e 

# - ~d
d~e R~c
The variance (Var) and standard error (SE) of the estimated fishtube passage mortality (1 -T )

or 

### survival (~ ) are:

VaT (1 -T) = VaT 

# (t ) (1 - St P A (1 - SP -4)



# RT R

SE(14) 

### =SE(t) = ';Va 

# (l-T)
The 90% confidence intervals on the estimated fishtube passage survival for the test condition 

### were calculated using the profile likelihood method (Hudson 1971). The profile likelihood method
constructs confidence intervals without the need to assume normality of 

### the parameter estimates and ,'.1

### are generally assumed superior to the normal approximations. 

### A likelihood ratio test was used to determine whether recapture probabilities were similar for dead (Pc

### ) and alive (PJ fish (RMC and Skalski 1994a

## , b). The statistic tested the null hypothesis of the simplified (REDUCED) model (Ho:P A = Pc

### ) versus the alternative of the most generalized (FULL) model (HA :P A :;Z!:P ). Depending upon the outcome of 

### this analysis the parameters and their associated 

### variances were calculated using the appropriate model. The survival model outputs are provided in 

### Appendix C.
3 . 0 RE'SUL TS 1 Testing Schedule and Conditions, and Smolt 

### Sizes 

### The study was conducted during 24-27 May, 1995. Treatment and control fish were 

### introduced on 24 and 25 May (see Appendix Bl for individual fish data), and all fish recaptured alive 

### were held for a 48 h period; the experiment ended at 1400 h on 27 May. Weather conditions during 

### the tests were overcast and mild. River water temperature varied from 160 C to 17.50 C; holding 

### pools water temperature varied from 17.50 C to 180 C.

The discharge through the fishtube was 40 cis throughout the testing period. 

### Turbine units
discharge during the 15 hours of 

### treatment and control fish introductions ranged from 1 795 cfs to 235 cis. Turbine discharge during 13 of the 15 hours was greater than 9 000 cis. 

### Additionally, 

### the fishpipe continually discharged 350 cis. 

### The salmon smolts varied in total length from 115 

### mm to 216 mm. The modal 10 mrn length class was 131- 

### 140 mID; the median length 

### of selected smolts was 141 mID. The treatment and control 

### groups length. distributions were similar with 64% of control group fish and 63 % of treatment groups 

### fish 150 mID. The minimum , maximum 

### , and mean lengths for treatment and control groups were 115 

### , 216 , 156 mID , and 119 

### , 200 , 149 mID 

### , r~pectively.
3.2 FISh Recapture

The recapture rates of treatment and control groups smolts were high and similar. 

### Seventy ( ~ 93 %) of the treatment group 

### smolts and all of the control group smolts were recaptured and held for the 48 h observation period (Table 1). 

### The amount of time between release and recapture was short and similar for treatment and control groups (Fig 5). 

### Most were recaptured within three minutes.

### Of the five non-recaptured treatment group smolts, at least one balloon tag was recovered



### from three of the smolts 

### , and a stationary radio-signal was received for a fourth smolt. The fifth treatment group smolt was designated as " unknown 

### " with no trace of the balloon tags or radio tag. The five non-recaptured treatment smolts were classified as " dead" for analyses purposes. Based on 

### the " 

### behavior 

### " of the radio signals, it is suspected that two of the non-recaptured smolts were preyed upon. One of 

### the control group smolts would have also been preyed upon if not recovered by a biologist. Just as the smolt 

### was being netted

### , a smallmouth bass attempted to consume the smolt. 

### Paired teeth marks and some minor scale loss were observed on the smolt. A frequency table by 

### study group and final classification is presented in Table 1.

3.3 Survival 

### Based on the likelihood ratio test to determine whethet recapture probabilities were similar for

dead (P~ and alive 

### fish , the null hypothesis (HO :PA 

### =PD) could not be rejected (p.c:::O. 

### Ol). 

### Therefore the simplified (REDUCED MODEL IN APPENDIX C) survival estimate model was employed. 

### Seventy of 75 treatment group smolts and all control group smolts were alive at Ih after recapture (Table 1). The estimated short-term 

### survival of smolts passed through the fishtube was 93. 

### 33%. All fish placed in holding survived the 48 h period, thus the long-term survival estimate was also 93. 

### 33%. Ninety percent confidence intervals for immediate and long-term survival were 

### identical (0. 876-0. 971)(Table 1). These 

### estimates should be considered conservative because five of 

### the 75 treatment groups fish were not recaptured an~ presumed dead , therefore absolute determination 

### of alive or dead was not possible. 

### If any of the non-recaptured fish survived , the true survival would be greater than the calculated estimate. 

### 4 Injuries Passage-related injuries to recaptured fish were few and minor. Only two of the 70 (2. 9%) 

### recaptured treatment group fish exhibited injuries. The observed injuries were scale loss of approximately 10% and 20% 

### , respectively, to the two smolts. 

### One control group smolt could be classified as injured. The injuries suffered (scale loss and teeth marks) were caused by a smallmouth bass attempting to 

### consume the smolt just as the recovery crew biologist was netting the smolt from the tailrace. 

### Given that the smolt was buoyed by the

### balloon tags, it is debatable that the attempted predation would have occurred on an untagged smolt.



### 0 DISCUSSION 

### A reliable estimate of survival can be made if the recapture of treatment and control groups 

### specimens is high and similar , and control group survival is high (Burnham et al. 

### 1987; Ruggles 

### 1993). High recapture rates, and high control survival result in fewer assumptions because more 

### information is absolute when test specimens can be examined in-hand, and treatment effects are better
isolated when adjustment for the control group is minim::!) 

### (Burnham et al. 1987). The HI-

### Z Turb' N Tag methodology facilitated high recapture and high control group survival; thus a simplified 

### statistical approach and reliable estimates were possible. Although the configuration of bypass structures and associated hydraulic characteristics differ 

### between sites, the estimated survival of Atlantic salmon smolts passed through the Vernon fishtube 

### was high and similar to that estimated for smolts passing through other turbine bypass structures (Heisey et al. 1993 

### , 1995). Heisey et al. (1993) reported Atlantic salmon smolt survival of about 

### 96 % in passage through ice-log sluices at the Bellows Falls and Wilder projects on the Connecticut River. The 

### slightly lower survival at Vernon may have resulted from non-recapture of five treatment 

### fish; these were assumed dead in the analysis. Interestingly, no dead fish were recaptured at Vernon. There was evidence that predation on smolts occurred and two treatment fish were classified preyed upon. 

### Additionally, during the preliminary (pre-study) testing of the treatment and control 

### fish induction systems , substantial predation was considered to have occurred when smolts were 

### discharged into a relatively calm area (Le. Units 9 & 10 were not 

### operating). Radio signals from 

### those smolts assumed to be preyed upon consistently settled along the rocky area adjacent to the 

### downstream. end of the fish ladder wall (Fig 2). Predation during the formal study was less most 

### likely due to discharge from Units 9 & 10. Thus it appears that predation on passed smolts may be 

### reduced if Units 10 and/or 9 are operated when possible during the emigration period. 

### The 

### significantly increased flow velocities due to turbine discharge in the vicinity of the fishtube may deter an accumulation of predators near the fishtube exit. 

### Of the five treatment smolts not recaptured

### , the radio signals from three of them were never received. Given a surmised low 

### risk of damage occurring to the radio tag in this particular situation (Le. passage through the fishtube), it was odd that no signals were received. One 

### potential 

### explanation is that the tags became dislodged from the fish in the fishtube and remained there in an

### undetectable location. If radio tags, and perhaps ID-Z Turb' N Tags were dislodged in the fishtube



### it would probably occur in a collision with the fishtube floor at the nearly right angle turn (Fig. 3), or perhaps by contacting debris that may have been lodged in the tube. 

### Given the high estimated survival and low observed injury rate, improvements to the fishtube may not be warranted. However

### , the following recommendations are provided:



### Debris that could lodge in the fishtube should be excluded from entering the tube or removed if lodged in the fishtube; 

### Operate Units 9 and 10 during the peak smolt emigration period, when river flow conditions permi4 to minimi7.

### e predation.

### LITERATURE CITED

Burnham 

### , K. P., D. R. Anderson 

### , G. 

### C. White 

### , C. Brownie, and K. H. Pollock. 1987. Design and 

### analysis methods for fish survival experiments based on release-recapture. Amer. Fish. Soc. 

## Monogr. 5:437 pp. Heisey, P. G., D. Mathur

## , and T. Rineer. 1992. A reliable tag-recapture technique for estimating 

### turbine passage survival: application to young-of- the-year American shad 

### (Alosa sapidissima). 

### Can. Jour. Fish. Aquat. Sci. 

### 49:1826-1834. 

### Heisey, P. G., D. Mathur , G. A. Nardacci 

### , and M. Anderson. 1993. Survival of Atlantic 

### salmon 

### smolts bypassed through ice-log sluices determined by the Hi- Z Turb' 

### N Tag. Reprinted from 

### Hydraulic Engineering ' 93. Proceedings of the 1993 conference July 25- , 1993 

### , San Francisco 

### , CA. 

### Heisey, P. , D. Mathur

### , and E. T. Euston. 1995. Fish injury and mortality in spillage and turbine 

### passage , pages 1416-1423. 

# :).

J. Cassidy (ed. 

### ) Proc. Intl. Conf. , Hydropower , Water 

### Power ' 95, San Francisco 

### , CA. 

### Hudson 

### , D. J. 1971. Interval estimation from the likelihood function. R. Stat. Soc. B. 33:256-

### 262. Mathur 

### , D. 

### , P. G. Heisey, and D. A. 

## Robinson. 1994. Turbine-passage 

### mortality of juvenile 

### American shad in passage through a low-

### head hydroelectric dam. Trans. Am. Fish. Soc. 123: 108- 

# 111.

Mathur 

### , D. 

### , P. G. Heisey, K.J. McGrath , and T. R. Tatham. 1995a. Relative survival of juvenile

blueback herring (Alosa aestivalis) 

### through a Kaplan turbine and over a spillway. Water Res. 

### Bull. (In press). Mathur 

### , D. 

### , P. G. Heisey, E. T. Euston 

### , J. R. Skalski 

### , and S. Hays. 1995b. Turbine passage survival

estimation for chinook salmon smolts (Oncorhynchus tshawytscha) at a large dam on the Columbia River. Can. Jour. Fish. Aquat. Sci (In press). 

### Normandeau Associates (NAI). 1995a. Efficiency of the louver system to facilitate passage of emigrating Atlantic salmon smolts at Vernon Hydroelectric Station , Spr.:ing, 1995. (Draft report dated December 1995). 

### NAI. 1995b. Exclusion and guidance of Atlantic salmon smolts by a fish diversion structure at Bellows Falls Hydroelectric Station

### , spring 1995. (Draft report dated August 1995). Prepared 

### for New England Power Company, Westborough, MA. 

### NAI. 1995c. Log sluice passage survival of juvenile clupeids at Cabot Hydroelectric Station Connecticut River , Massachusetts. Report prepared for Northeast 

### Utilities Service Company, 

### Hartford , CT.

### Ricker , W. E. 1975. Computation and interpretation of biological statistics of fish population. Fish Res. Bd. Can. Bull. 191:382p. 

### RMC and J. R. Skalski. 

### 1994a. Survival of yearling fall chinook salmon smolts 

### (Oncorhynchus

tshawytscha) 

### in passage through a Kaplan turbine at the Rocky Reach hydroelectric dam 

### Washington. Report prepared for Public Utility District No. 1 of Chelan County, Wenatchee WA. 

### RMC and J. R. Skalski. 1994b. Survival of juvenile fall chinook salmon 

### (Oncorhynchus

tshawytscha) 

### in passage through a fixed blade Kaplan turbine at the Rocky Reach Dam 

### Washington. Report prepared for Public Utility District No. 1 of Chelan County, Wenatchee 

### WA. Ruggles , C. 

### P. 1993. Effect of stress on turbine fish passage mortality estimates. Pages 39-57.



### P. Williams 

### , D. A. Scruton 

### , R.F. Gooney, C. 

### E. Bourgeois, D. 

### C. Orr

### , and C. P. Ruggles (008. 

### ). Proc. Workshop On Fish Passage at Hydroelectric Developments, St. Johns , New 

### Foundland 

### , Canada. Skalski , J .

### R. 1992. Statistical review of the RMC tagging study. Report prepared for Chelan County 

### PUD 

### , Wenatchee , WA.

### Table 1. Frequency tabulation by group and classification of smolts 

### , and estimates of percent survival



### adjusted for controls, during Vernon fishtube survival study, May 1995.

Treatment Group 

### Control Group Totals 

### Number Released 100 

### Number Recaptured Alive Number Recaptured Dead 

### Number Recaptured Alive 

### , with Injury Number of Inflated Tags Only Recaptured * 

### Preyed Upon * 2** 1*** 

### Unknowns * 

### Number Alive at 48 Hours Adjusted percent survival and percent injured. and corresponding standard errors and confidence intervals. 

### Estimated Passage Survival, 

### T , (1 h) 93. 33%

Standard Error of 

### , (%)

62% 90% Confidence Interval (%) 

### 87. 

### 55% - 97. 06% 

### Estimated Passage Survival , (48 h) 

### 93. 33%

Standard Error of 

### , (%)

62% 90% Confidence Interval (%) 

### 87.55% - 97. 06%

Classified as " 

### dead" 

### This is a subset of the value in " No. of inflated tags only recovered" Recovery crew rescued this smolt during predation attempt by smallmouth 

### bass. ***Miles 

## White River 

### ..Junction,

C')

:::

c:: 

## Wilder Dam Lebanon,



## Figure 1. Map of the Connecticut River showing the location of 

### Vernon Project. 

## Bellows 

# Falls Dam



# Brattlebora Vernon Dam 

## Hinsdal e, 

## Vernon..~\~Tainter GatesL---,......oo..........Fishpipe1::11::11::11::11::11::11::11::11::11::1UnderwaterFlood GatesSluice100300500feetFigure 2. Plan viewofthe Vernon Project.FI.blu'" E\OTallrac.EL.186.....-...IG"allrac0UnitEL.223.EL.213.EL.187.24": ,.Figure3.schematic cross section of VernonProject bypass fishtube (nottoscale).'="""'=,"~"~""""'=c.:,-c. 'EL.237.Normal Pond EL221.-----------Gate atFI.htubeEL. 203.EL.' 187.Tran.mon of FI.htube FromRectangularToRound.Removable SlandPIPTank Waterupply LInePre-release TankSupport FrameValveIntake Water Hose(gravity fed or gas/electric pump.....Induction PipeFish Delivery LIne'\.Figure 4. Typical Induction system used to Introduce treatment and control Atlantic salmon smolts.......ell 3015 .a~:~GJQ. .5'0 20150:1O\50:lOnmiXI5. -----_.,,-_.Figure 5. Frequency distribution of elapsed times between release and recapture times forcontrol and treatment smolts during the Vernon bypass evaluation study,May 1995.15 -,10-Elapsed Time (minutes)treatmentN=75, ~i ~tJj ~SAMELE _

### SIZE DETERMINATION



### One of the important considerations in study plan development is the statistical determination 

### of an appropriate number of fish needed ' to obtain an estimate of survival within a pre-specified 

### precision level (i.e. , within :!: 

### 10% 90% of the time). The sample size is a function of the recapture

probabilities (P), expected passage survival (T) or mortality 

### (I- T), 

### survival probability of control 

### fish (S), and the specified level of precision. In general 

### , the sample size requirements decrease as passage survival

### , control survival, or recapture rates increase. Results of previous studies (e. Heisey et al. 1992; Mathur et al. 

### 1994; RMC and Skalski 1994a b) provide conservative preliminary 

### estimates on the recapture and control survival probabilities that might be expected. Calculations 

### utilize such information, or perhaps site specific information obtained during small scale preliminary studies 

### , to estimate sample sizes to obtain a specified precision on the passage survival estimate. The 

### derivation of precision is shown in the following pages. Using a 

### range of parameter values, potential 

### sample sizes can be calculated. The sample size can vary significantly, and the range of sample sizes 

### can include some reasonably small values particularly if control survival and recapture rate are high. For example 

### , these calculations show that in order to obtain a precision of :t 10% on the point

estimate of survival at alpha 

## (a)=0. paired releases of 23 treatment and control fish would be 

### needed if the expected passage survival is 0. , the control survival is 0. 

### 99, and recapture rate is 99. The study 

### plan included an estimated sample size of 75 treatment and 25 control group smolts 

### to incorporate some flexibility to account for the realized control survival level , recapture rate 

### , and passage survival.AMPLE 

### IZE AND PRE N D RIV A TI



### The estimation for the sample size requirements discussed in the text are given herein. The precision of the estimate was defined as: e.c::i - 

## i:.c::e) = 

# I-a where 

## ?: =

estimated survival in passage through fishtube

e = half-width of a (1-a) 

### 100% confidence interval for?: or 1- Using the above precision definition the required total sample size (R,,) is as follows:

;~ i) .c:: z.c:: :( i) ) = 1 -

(z.c:: -e ) = a/2 

## Var(1:) 

# ) =a/2 't' Var ( 1: )

Var( i) 

### a/2

var(i) 

# 1: ( I-S1:P) 

# (I- Sp) 

# 1: 1 e 

# SP R

# T R 2 a


### Letting Rc=RT 

### , the sample size for each release is1: 

### Zl-a12 

### (1+1:- 2S1:P) SP
where P = 

### recapture probability, and S = control group survival probability. 

### The variance (Var) of the estimated passage survival (;. ) or mortality (1- ;') is:

Var (i) 

# Var (1- i) = -E- ( (1 - 

### S1:P) (1 - 

### SP)"C



# SP R 'l' R
and associated standard error

SE i) SE 

### ( 1- i) = 

# var (1:) or Var 

## 1:) .

## APPENDIX Bl INDIVIDUAL F1SH DATAAppendix Tabla 81. Short-tenn bypau IUh tube survival data on trcaIment aad control Atlantic salmon amolt8 at Vemon Hydroelectric

Station. spring 1995. Description of condition codes is prcsc:aa:d in Appendix Table B2. rUDe F'uh TurbiN or Data F1Sh No. Tocallcngth Radio tagged rclcascd rcc:ovC%Cd At large Alive/Dcad Condition No. Tags No. Tags condition miD) At 1 Hour Code atmched m:a codes 24 May 1995 - Lot C1 Co1llrol Unit 20 WarD' Temp 16. 0 C

196 YES 9:.35 10:04 10:13 ALIVE 152 YES 9:.36 10:17 10:19 ALIVE A.A 153 YES 9:37 10:10 10:16 ALIVE A.A 135 YES 9:38 10:06 10:08 ALIVE 155 YES 9:40 10:19 10:20 ALIVE 145 YES 9:45 10:42 10:44 ALIVE 185 YES 9:47 10:44 10:45 ALIVE 147 YES 9:48 10:.32 10:.35 ALIVE 200 YES 9:49 10:26 10:30 Desig. pIed PDQ 140 YES 9:51 10:22 10:25 ALIVE 200 YES 10:28 11:06 11:11 ALIVE 133 YES 10:29 11:13 11:14 ALIVE 178 YES 10:35 11:08 11:10 ALIVE 153 YES 10:36 11:01 11:04 ALIVE 119 YES 10:37 11:00 11:05 ALIVE 130 YES 10:50 11:.34 11:38 ALIVE 131 YES 10:51 11:23 11:25 ALIVE 146 YES 10:52 11:17 11:30 ALIVE 135 YES 10:53 11:25 11:28 ALIVE 128 YES 10:54 11:.32 11:33 ALIVE 144 YES 11:14 11:57 11:59 ALIVE 133 YES 11:16 11:48 11:50 ALIVE A.A 136 YES 11:17 11:44 11:46 ALIVE 120 YES 11:28 11:49 11:54 ALIVE 141 YES 11:29 11:53 11:56 ALIVEAppendix Tabla B1. Short.(Crm bypass fish tUbe survival data on treatment and conaolAdantic salmon smolts at Vernon Hydroelectric

StaDon. spring 1995. DcIcripc:ion of conditi.an codes is prescnt&:d in Appendix Table B2. T'lDIe Fish Turb'N 

## Tn Data FISh No. Total Icngth Radio tagged rclcascd recovered At Iargc AJiveIDead Condition No. Tags No. 

## Tap condition

(rum) Ta22cd? (miD) At 1 Hour Code attached recaptured codes
24 May 1995 - Lot Tl Test Unil 20 Water temp 17.5

216 YES 13:49 14:41 Desig. dead 141 YES 13:51 14:14 14:20 ALIVE 125 YES 13:52 14:52 14:54 ALIVE 115 YES 13:53 14:20 Unknown 130 YES 1.3 :54 14:37 14:39 ALIVE 195 YES 14:05 15:05 15:07 ALIVE 196 YES 14:06 15:21 15:23 ALIVE 141 YES 14:07 14:57 14:58 ALIVE 162 YES 14:08 15:19 15:21 ' ALIVE 137 YES 14:09 15:14 15:16 ALIVE 192 YES 15:00 15:28 15:29 ALIVE 212 YES 15:02 15:53 15:55 ALIVE 126 YES 15:05 15:32 15:34 ALIVE 152 YES 15:06 15:54 15:57 ALIVE 123 YES 15:07 15:57 15:58 ALIVE 204 YES 15:33 16:28 16:30 ALIVE 120 YES 15:34 16:20 16:22 ALIVE 151 YES 15:36 16:31 16:33 ALIVE A,A 167 YES 15:37 16:26 16:28 ALIVE 164 YES 15:39 16:15 16:17 ALIVE ..,

157 YES 16:01 16:45 16:48 ALIVE 197 YES 16:02 16:39 16:40 ALIVE 204 YES 16:04 16:40 16:43 ALIVE 134 YES 16:08 16:48 16:49 ALIVEAppendix Table B1. Short-tcnn bypass .fish wbc survival data 00 treatment and control Atlantic salmon smolts at Vemon Hydroc:1cctric

Station, spring 1995. Description of condition codes is presented in Appendix Table 82. T'UDe 

## rub TurbiN TQ Data ruh No. Total length Radio tagged released recovered At large AlivcIDcad Cooditioo No. Tags No. Tags condition

(mm) Ta22cd7 (mia) At 1 Hour Code attached codes 127 YES 16:09 16:44 16:45 ALIVE 157 YES 16:31 16:59 17:02 ALIVE A.A 142 YES 16:32 16:56 16:57 ALIVE 127 YES 16:34 16:58 17:01 ALIVE 127 YES 16:35 17:04 17:06 ALIVE 124 YES 16:52 17:11 17:12 ALIVE

2S May 1995 - Lot 72 - Test Unil 20 - Water temp. 17.

200 YES 8:53 9:44 9:45 ALIVE 135 YES 8:54 9:50 9:53 ALIVE 134 YES 8:57 9:46 9:48 ALIVE 128 YES 8:58 9:48 9:50 ALIVE 140 YES 8:59 9:53 9:54 ALIVE 153 YES 9:07 10:11 10:13 ALIVE 124 YES 9:08 10:01 10:03 ALIVE 128 YES 9:09 9:57 10:00 ALIVE 205 YES 9:10 10:10 10:12 ALIVE A.A 122 YES 9:11 10:03 10:07 ALIVE A.A 140 YES 9:59 10:37 10:38 ALIVE 139 YES 10:00 10:42 10:53 ALIVE 129 YES 10:01 10:35 10:37 ALIVE 120 YES 10:09 10:40 10:42 ALIVE BoA 193 YES 10:13 11:12 11:15 ALIVE 120 YES 10:14 10:48 Desig. dead 159 YES 10:15 11:18 11:19 ALIVEAppendix Table Bl. Short-term bypass fish tube survival data on treatment and concrol Atlantic salmon smolts at Vernon Hydroelectric

Station, 

### sprinll99S. Dcscript:ion of condition codes is prcscntcd in Appendix Table B2.. TIlDe FISh Turb'N T Data tagged rclcucd rccovcted At large AlivcJDcad Condition No. Tags No. Tags condition nUn) At 1 Hour Cadc attached rcca cod= 150 YES 10:26 11:24 11:26 ALIVE 135 YES 10:27 11:14 11:15 ALIVE A.A 151 YES 10:28 11:20 11:23 ALIVE 138 YES 10:29 11:29 11:32 ALIVE 131 YES 10:30 11:21 11:29 ALIVE 123 YES 10:31 11:34 11:35 ALIVE 128 YES 10:44 11:35 11:37 ALIVE 124 YES 10:45 11:42 11:43 ALIVE A.A 194 YES 10:52 11:40 11:42 ALIVE 131 YES 10:53 11:38 11:40 ALIVE 139 YES 11:16 11:46 11:48 ALIVE 200 YES 11:17 11:44 11:46 ALIVE A.A 165 YES 12:11 13:03 13:05 ALIVE 176 YES 12:12 13:15 13:19 ALIVE 141 YES 12:13 13:11 13:14 ALIVE 130 YES 12:14 13:01 D=ig. dead 148 YES 12:16 13:17 13:19 ALIVE A.B 121 YES 12:18 13:20 13:22 ALIVE 198 YES 12:20 13:34 13:36 ALIVE 144 YES 12:21 13:28 13:29 ALIVE 141 YES 12:22 13:31 13:33 ALIVE 136 YES 12:23 13:22 13:24 ALIVE 137 YES 12:25 13:47 13:50 ALIVE 128 YES 12:26 13:38 13:41 ALIVE 195 YES 12:29 13:49 AX.Appendix Table 81. Sbort-(em1 bypau fiab tube survival data on trealmCDt and conuol Adantic salmon smolts at Vernon HydracJcctric

Station, 

### sprmll99S. DcIc:ription of condition codc8 is in Appendix Table B2. TIlDe Fish Turb'N TaR Data FISh No. 

### Total)cap Radio 

### tagcd n:1casc:d recovered At large AlivcJDcad Condition No. Tags No. Tags condition 

## (mm)

# Ta22Cd1 (min) At 1 

# Hour Code 

# attached codes 131 YES 12:30 13:45 13:46 ALIVE A.A 150 YES 12:33 13:43 13:45 ALIVE 146 YES 12:35 13:39 13:40 ALIVE

## APPENDIX B2 

## FISH AND TURB' 

## N TAG CONDITION CODESAppendix Table B2. 

### Condition codes assigned to fish and Turb' 

### N Tags during a fish passage survival

study.


### No visible marks on fish Flesh tear at tagging site(s) 

### Minor scale loss , 3 to 20% 

### Major scale loss, ;::. 20% Laceration(s); Tear(s) 

### Severed Body Parts 

### Hemorrhaging, bruised Stressed (lethargic , swimming poorly or sporadically) Spasmodic movement of body 

### Very weak

### , barely gilling, died wi~in 15 minutes of recovery 

### Fish failed to enter system 

### Fish likely preyed on based on telemetry and/or circumstances relative to Turb' N Tag 

## Substantial bleeding at tag site Bulging or missing eye(s) 

### Observed predator attack or marks indicative of predator Other information 

### Necropsied , no obvious injuries 

### Necropsied, internal injuries observed Trapped inside tunnel/gate well 

### Not recaptured , no Turb' 

### N Tag(s) recovered , radio signal stationary, assign status 

### dead 

### Not recaptured , sighted swimming in tailrace , assign status 

### alive 

### FISH RECOVERY CODES

Alive when recaptured or not recaptured - assigned 

### alive Dead when recaptured or not recaptured - assigned 

### dead 

### Unknown 

### TURB'N TAG CODES Fully inflated Partially inflated Pinhole, leaking 

### Burst Not inflated at all 

### Detached from fish

## APPENDIX C 

## SURVIVAL MODEL OUTPUTAppendix Table C. 

### Survival Model Output - Reduced Model results reported. Es~i..~ing pa~amete~s fo~ HODEL .1 

# ~ing 90 pe~cent profile likel ihood inul'"Val. Compu~ing 95 pe~cent profile likelihood in~el'"Val. 

# C~ing 99 pe~cent profile likelihood in~el'"V8l.

RESULTS FOR FULL HODEL (UNEQUAl. LJVEIDEAD RECDVERy)

estim. s~d. 

### err.

N/A N/A 9980 (0. 0199) 9332 (0. 0288) 0668 (0. 0288) 

### Control 91"OUP sul'"Viv8lLive recovery probab it i 

## t-r Dead recovery probabi l ity Turbine survival Turbine DIOrul ity s = pa = Pd = Tau = 1-Tau = 

# . --

Because of 

### contraints in the data set , this probabil it"( is asSUDed equal to 1. 0; not estimated. log-likelihood: -18. 468288 Variance-Covariance matrix for estimated probabilities: 

### 000l.0 0. 00000 00000 0. 00083 Profi le l ikel ihood intervals:

Turbine survival 90 percent: (0. 8754 . 0. 9705) 95 percent: (0. 8620, 0. 9755) 99 percent: (0. 8338, 0. 9834) Turbine mortal ity (0. 0295 , 0. 1246) (0. 0245, 0. 1380) (0. 0166, 0. 1662)

Estimating parameters for MODEL #2 fletch finished (1) CQGI!:IUt,

### ing 90 percent profi le 

# ~ing 95 percent profi le COmputing 99 percent profi 

### likelihood intel'"Val. likelihood interval. likelihood interval.

RESULTS FOR , REDUCED MODEL (EQUAL LIVEIDEAD RECOVERY)

estim. std. err. S = MIA Control group survival* Pa = Pd 9999 (0. 0010) Recovery probaDi l i ty Tau = 9333 (0. 0288) 

### Turbine survival 1.Tau = 0667 (0. 02S!n Turbine mortal ity 

# . --

Because of contraints in the data set , this proCability is assumed equal to 1. 0; not estimated. 

### log-likelihood: .18. 471165 Variance-covariance matrix for estimated probabi 

### l ities: 00000 0. 00000 00000 0. 00083 Profile likelihood intervals:

Turbine survival (0. 8755, 0. 9706) (0. 8621, 0. 9756) (0. 8339 , 0. 9835) Turbine mortaL it"(

(0. 0294, 0. ,1245) (0. 0244, O. 1379) (0. 0165, 0. 1661) 

### 90 percent: 

### 95 percent: 99 percent:

Likelihood ratio statistic for equality of 

### recovery probabilities:

005754 

# C~re with quantiles of the chi- squared distribution with 1 d. 

### For significance level 0. 10: ' 706 

### For significance level 0. 

## 05: 3. 841 For significance level 0. 

## 01: 6. 635