Laboratory Evaluation of

Fish Protective Devices at Intakes

RESEARCH REPORT 8.

Prepared By

ALDEN RESEARCH LABORATORY AND

STONE & WEBSTER ENGINEERING CORPORATION

FINAL REPORT

MA Y 1981

EMPIRE STATE ELECTRIC ENERGY RESEARCH CORPORATION
Members of the

Empire State Electric Energy Research Corporation

1271 Avenue of the Americas, New York , N.Y 10020

CENTRAL HUDSON GAS & ELECTRIC CORPORATION

CONSOLIDATED EDISON COMPANY OF NEW YORK, INC.

LONG ISLAND LIGHTING COMPANY

NEW YORK STATE ELECTRIC & GAS CORPORATION

NIAGARA MOHAWK POWER CORPORATION

ORANGE AND ROCKLAND UTILITIES, INC.

ROCHESTER GAS AND ELECTRIC CORPORATION
LABORATORY EVALUATION OF

FISH PROTECTIVE DEVICES AT INTAKES

Alden Research Laboratory

Stone & Webster Engineering Corporation

Research Sponsored by

Empire State Electric Energy Research Corporation

George E. Hecker, Director

ALDEN RESEARCH LABORATORY

WORCESTER POLYTECHNIC INSTITUTE

HOLDEN , MASSACHUSETTS

February 1981
This report was prepared as an account of research sponsored by ESEERCO

and conducted by the Alden Research Laboratory (ARL) and Stone 0 webster

Engineering Corporation (SOW). Neither ARL, sow, nor any of its employees,

contractors, or sub-contractors

a. Makes any warranty, expressed or implied, or assumes any legal

liability or responsibility

for the accuracy, completeness, or usefulness of any information , apparatus, product, process disclosed, or

for any consequential loss or damage as a result of its use,

such as loss of profit, damage to the environment, or interest during construction, if any, irrespective of negligence.

b. or represents that its use would not infringe privately owned

rights.
TABLE OF CONTENTS

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

SECTION 1 - INTRODUCTION

1.1

1. 2

1. 3

Background

Development of the ESEERCO Study Program

ESEERCO Study Program

SECTION 2 - FISH HOLDING FACILITY

Alewives

Striped Bass, White Perch, Atlantic Menhaden

SECTION 3 - ANGLED SCREEN TESTING - SALT WATER TEST FLUME

In troduction

Description of the Facility

Biological Testing Procedures

Analytical Results

SECTION 4 - ANGLED BEHAVIORAL BARRIERS

Introduction

Description of the Facility

Biological Testing Procedures

Resul ts

SECTION 5 - FISH PUMPS

Introduction

Peripheral Type Jet Pump

Hidrostal Pump

SECTION 6 - OFFSHORE INTAKE - BEHAVIORAL BARRIER STUDY

REFERENCES

Introduction

Description of the Facility

Biological Testing Procedures

Analytical Results

Page No.

iii
Table 1.

Table 2.

Table 3.

Table 3.

Table 3.

Table 4.

Table 4.

Table 5.

Table 5.

Table 5.

Table 5.

Table 5.

Table 6.

Table 6.

LIST OF TABLES

Fish Protection Studies Conducted from 1973-1979

Collection Data

ESEERCO Angled Screen Results

Summary Statistics

ANCOVA - Angled Screen Study, Full Model

ESEERCO Behavioral Barrier Test Results, Salt

Water Facility

Summary of Behavioral Barrier, Test Results by

Species, Salt Water Facility

Jet Pump Test Data, 1978 Juveniles

Analysis of Covariance, Jet Pump, 1978 Juveniles

Test Data Summary, Jet Pump

1978 Hidrostal Pump Data (White Perch, Striped

Bass, Menhaden)

1979 Hidrostal Pump Data, Alewives (9. 9 to lO. 2cm)

Offshore Intake Model, 1978 Behavioral Barrier

Test Results, Alewives

ANCOVA - Behavioral Barrier Study

Page No.
Figure 2.

Figure 3.

Figure 3.

Figure 4.

Figure 4.

Figure 5.

Figure 5.

Figure 5.

Figure 5.

Figure 5.

Figure 5.

Figure 6.

Figure 6.

Figure 6.

Figure 6.

Figure 6.

Figure 6.

LIST OF FIGURES

Fish Holding Facility

Salt Water Test Facility with 250 Angled Screen

Salt Water Flume with 250 Angled Screen

Hanging Chain Diversion Barrier

Water Jet Diversion Barrier

Jet Pump Test Facility

Jet Pump Test Facility

Histogram of Jet Pump Mortality, All Species

96 Hour Jet Pump Mortality versus Temperature

Difference, All Species

Hi stogram of Mortality Partitioned by Species,

Jet Pump Tests

Hidrostal Pump Test Facility

Offshore Intake Test Facility

Intake Segment Structure for Testing

Behavioral Barriers

Intake Segment Structures

Hanging Chain Behavioral Barrier, Offshore

Intake Study

Air Bubble Behavioral Barrier, Offshore

Intake Study

Water Jet Behavioral Barrier, Offshore

Intake Study

Page No.
SECTION 1

INTRODUCTION
SECTION 1

INTRODUCTION

From 1977 to 1979, Stone & Webster Engineering Corporation and the Alden

Research Laboratory (ARL) of Worcester Polytechnic Institute (WPI) conducted a program of biological testing for Empire State Electric Energy

Research Corporation (ESEERCO) to investigate the effectiveness of various fish protective systems in terms of their possible development for

general application to power plant intakes in New York state. This report presents the results of studies conducted specifically for ESEERCO

from 1977 to 1979. To aid in understanding the rationale for investigating selected systems and operational variables in these studies, the

following discussion presents a brief summary of the various studies previously conducted by ARL and Stone & Webster which led to the ESEERCO

study program.

Background

The ESEERCO program was an extension of several independent intake design

studies conducted for several utilities in New York state from 1973 to 1977.

During those investigations, physical models were constructed and were used

to develop selected fish protective systems for reducing entrapment and impingement of juvenile fish on the Great Lakes and in the Hudson River. Systems which were evaluated included:

Fish diversion and bypass devices for application at onshore screenwells and offshore intake structures.

Fish transportation systems for returning bypassed fish to their

natural environment.

Fish deterrent devices (behavioral barriers) for preventing fish

entrapment at offshore intakes.
A listing of individual studies, species tested, dates of testing, utility

sponsors, and references for study reports are given in Table 

listed are the ESEERCO studies presented in this report.

Also

As a result of past studies (excluding ESEERCO studies), a complete fish

diversion, bypass, and transportation system was developed. This system

was designed to use an angled, flush-mounted traveling screen for diverting fish to a bypass pipe for transportation back to their natural environment. The motive force for inducing bypass and transport pipe flows is a

jet pump. Results of laboratory testing of this system showed that it was

highly effective in diverting and transporting the relatively fragile alewife (Alosa pseudoharengus) with low resultant mortality. The angled, flushmounted traveling screen was also shown to be nearly 100 percent effective

in guiding striped bass (Morone saxatilis), white perch (Morone americana),

and Atlantic tomcod (Microgadus tomcod) to a bypass with very low mortality.

In addition to diversion and transportation systems, studies with behavioral

barriers indicated that such devices, when properly designed, might be partially effective in reducing fish entrapment at offshore intake structures.

Devices tested included an air bubble curtain, a hanging chain barrier, and

a water jet curtain.

Development of the ESEERCO study Program

At the completion of these studies, it was possible to place varying degrees

of confidence on the various systems investigated relative to their potential

for effectiveness at different sites in New York. Since the angled, flushmounted traveling screen had been shown to be highly effective with lake and

river species, it appeared that this device had good potential for general

application in these water bodies. Experimental data on its effectiveness

f or guiding marine species were lacking, however.
The fish transportation system, incorporating pipe and jet pump elements,

had been evaluated for a lake condition, the alewife being the primary

species tested to date. Since the hydraulic criteria (particularly total

head) required for lake application with offshore intakes would be more

stringent than those which would be required for application at shoreline

intakes, it appeared that a piping and jet pump system would also offer

a practical engineering solution to the problem of transporting fish at

river and marine sites utilizing shoreline intakes. Al though this system

had not been evaluated with key species from these environments, tests had

shown that the alewife , a fragile species, may be transported with low mortality in this system. Therefore, it appeared that a jet pump and piping

arrangement might be effective in transporting other species.

In summary, the greatest degree of confidence in fish protective systems

studied up to 1977 had been placed on an angled traveling screen and transportation systems with Lake Ontario fish, specifically the alewife. The

angled screen had also been shown to be highly effective in diverting the

Hudson River fishes, but a transportation system had not been evaluated.

studies with marine species had not been conducted. Finally, behavioral

barriers appeared to have some potential for reducing fish entrapment at

offshore intake structures, but had not been studied extensively for use

at shoreline intakes.

ESEERCO Study Program

On the basis of the stages of development of the various fish protection

systems investigated up to 1977, systems and test parameters were selected

for evaluation as part of the ESEERCO study program. Systems included an

angled, flush-mounted traveling screen, a jet pump, and three behavioral

barriers to be evaluated with juvenile Atlantic menhaden , striped bass,

whi te perch , and alewife. The goal of these studies was to provide data

on fish protection systems so that their potential for general application

for protecting juvenile fish at lake, river, estuarine, and marine sites

could be determined with greater confidence.
The specific objectives of the study were to:

Determine the effectiveness of an angled screen in diverting all

test species to a bypass at previously untested screen angles and

veloci ties.

Evaluate the potential of fish pumps for transporting striped bass,

whi te perch , and menhaden with low resultant mortality.

Determine the effectiveness of air bubble , water jet, and hanging

chain behavioral barriers in preventing alewife entrapment into

an offshore intake model at low water temperatures.

Determine the effectiveness of hanging chain and water jet behavioral barriers arranged at an angle to the flow in guiding striped

bass, white perch, and menhaden to a bypass.

This report presents the methodologies and results of this evaluation

, conducted for ESEERCO from 1977 to 1979. Concurrent with this study, ARL and

stone & Webster conducted a related study program for ESEERCO in which finemesh screening systems were investigated to determine their potential for

protecting fish larvae at power plant intakes. The results of this program

will be presented in a separate report (ESEERCO, 1981).
Fish Protection System

I. Fish Diversion

A. Louvers

1. 3- ft flume

2. Salt water flume

B. Angled Screen

1. 3-ft flume

2. Full Scale Model

3. System Demonstration Model

4. Double Jet Pump

5. Salt water flume

(1975- 1976)

6. Salt water flume

(1977- 1978)

7. Larval Diversion

Angled Screen

8. Angled Behavioral Barriers (chains, water jets)

TABLE 1. 1

Fish Protection Studies Conducted from 1973 - 1979Species Tested

Alewife

Coho salmon

Rainbow smelt

Whi te perch

Striped bass

AlewifeAlewife

AlewifeAlewife

Striped bass

Whi te perch

Tomcod

Striped bass

Whi te perch

Menhaden

Winter flounderAlewife

Striped bass

MenhadenStriped bass

Whi te perch

Testing Period

Aug. - Oct. 1973

Jan. - Apr. 1974July - Oct. 1974Sept. 1975 - Jan. 1976

Sponsored

Reference

NMPC S&W, 1975a

Con Ed S&W, 1975b, 1976c

July - Nov. 1974 NMPC S&W, 1975aJune 1974 - Jan. 1975 NMPC S&W, 1975aOct. 1975 - Oct. 1976 NMPC/RG&E S&W, 1976a, 1976b, 1977aJuly - Aug. 1976 NMPC S&W , 1977b

May 1975 - Jan. 1976 Con Ed S&W, 1975b, 1976c

July 1977 - Mar. 1978June - July 1978

Oct. 1978 - Mar. 1979

ESEERCO See TextESEERCO See Text

ESEERCO See Text
Fish Protection System

II. Behavioral Barrier

A. 3- ft Flume - Air

Bubbles, Chains,

Visual Keys

B. Offshore Intake

Model-Air, Chains,Water Jets (1976)

C. Offshore Intake

Model-Air, Chains,

Water Jets (1978)

III. Fish Pumps

A. Jet Pump

1. Core-type

2. Peripheral Type

(1974)

3. Peripheral Type

(1978)

4. Hidrostal Pump

Species Tested

Alewife

Rainbow smelt

AlewifeAlewife

Coho salmon

Smelt

Alewife

Coho salmon

Smelt

Alewife

Striped bass

Whi te perch

Menhaden

AlewifeWhi te perch

Striped bass

Menhaden

Alewife

TABLE 1.continued)Testing Period

Sept. - Dec. 1975

Apr. - May 1976

June - Aug. 1976Aug. - Dec. 1978

Feb. 1974Feb. 1974July - Aug. 1974Jan. - Feb. 1974Jan. - Feb. 1974

July - Oct. 1974Sept. 1978 - Feb. 1979Oct. 1978 - Nov. 1979

SponsoredNMPC/RG&E

NMPC/RG&EESEERCO

NMPCNMPC

ESEERCOESEERCO

Reference

S&W , 1976aS&W, 1976bSee Text

0'\

S&W, 1975a, 1977a

S&W, 1975a, 1977a

See TextSee Text

NMPC = Niagara Mohawk Power Corporation

RG&E = Rochester Gas & Electric Corporation

S&W = Stone & Webster Engineering Corp.

Con Ed = Consolidated Edison Co. of New York, Inc.

ESEERCO = Empire State Electric Energy Research Corp.

NOTE:
t-rj

::r:

::r:t"i

t-rjt"'

0-,3

tIJ

t-3!'oJ
SECTION 2

FISH HOLDING FACILITY

All fish used during the study program were collected by individuals contracted by ESEERCO and were delivered to ARL by these individuals. The

holding systems utilized for each species were initially designed to meet

the specific requirements of that species. However, since the laboratory

was remote from the natural habitat of all species tested, some modifications to the holding system design or operation were found necessary to

enhance survival and were, therefore , implemented during the study. To account for any differences in behavior or survival of test fish which might

have occurred during the two- year study as a result of changing the holding

techniques, separate groups of control fish were held for all tests in which

latent survival was the variable of interest. Controls were handled in an

identical manner as the test fish except that they were not exposed to the

particular test device under study.

Table 2. 1 presents, for each species, the total number of fish obtained for

testing and their length range. All species were collected by beach seine.

In this report , lengths reported are overall ranges (not mean lengths) of a

subsample of fish measured each day that tests were conducted. Since this

study was designed to determine the effectiveness of protection devices on

a particular life stage, no attempt was made during data analyses to determine the effect of specific lengths within that life stage on effectiveness.

Alewives

In 1978 , alewives were held in two 2500 gallon circular tanks measuring 12

ft in diameter and 3 ft in depth. They were held in a semi-closed system

whereby filtered stream water (salinity = 0 ppt) was pumped into each tank

during the day at a rate of about 50 gpm. At night , the system was isolated from the stream by turning off the feed pump and aerating the water with

powered aerators to maintain the desired dissolved oxygen levels. The fish

were maintained exclusively on pulverized trout pellets during the entire

1978 study.
In 1979, alewives were held in the same facility as in 1978. The mode of

operation was changed to once-through rather than semi-closed. The holding system was a once-through design whereby stream water was pumped into

each tank at a continuous rate of about 50 gpm. The fill pipe was angled

to provide a circular flow to which the fish could orient. The discharge

drained out an overflow pipe. The water, as it was pumped from the stream,

was not filtered so that the alewives would have a source of natural plankton to feed upon. The natural food source was supplemented with pulverized

trout pellets which were readily accepted by the alewives. During the 96

hour mortality holding period, both test and control groups were held in

circular tanks, 3 ft across by 2. 5 ft deep, with netting covering the bottom. The tanks were floated in a sump utilizing the same water source

used in the stock holding tanks and test model. Test and control fish

were fed identically to those in the stock holding tanks.

Daily measurements of pH, dissolved oxygen , and ammonia-nitrogen were taken

to monitor water quality. Since many juvenile alewives were held (1 fish/

2L) and the BOD was high, powered aerators were used to keep the dissolved

oxygen level at or near saturation.

The alewives used in 1978 and early 1979 were collected and transported to

ARL by a wholesale bait dealer from Wanaque, New Jersey. The fish , which

were landlocked alewives from local New Jersey lakes and reservoirs, arrived in two batches; the first in August and the second in October 1978. Over

the course of the study, fish lengths ranged from 5. 9 to 12. 4 cm.

Alewives tested in the fall of 1979 (Hidrostal pump tests) were obtained

from the same source in a single batch, and ranged in length from 9. 9 to

10. 2 cm. A total of 27 000 alewives were delivered to the laboratory

during the study program; upon arrival, the fish were in good condition;

little mortality occurred during transport.
Striped Bass, White Perch, Atlantic Menhaden

Striped bass, white perch, and Atlantic menhaden were held separately in

2500 gallon circular tanks measuring 12 ft in diameter and 3 ft in depth.

The stock holding tanks were closed- cycle systems each with a biological

filter, physical absorption filter, and rapid sand pressure filter (see Figure 2. 1). The biological filter removed ammonia-nitrogen from the water

thereby maintaining ammonia at a low level. The physical absorption filters removed dissolved organics and aided in maintaining water clarity. The

rapid sand pressure filter removed solid fish wastes from the water column

and provided a flow to which the fish could orient.

The use of closed- cycle systems for these species allowed the addition of

synthetic sea salt, since previous experience at the laboratory had shown

that salinities of 2 to 7 ppt enhanced stock holding survival. Atlantic

menhaden were held in 3 to 5 ppt salinity since it was necessary for their

survival.

While it was possible to conduct laboratory tests under slightly saline

conditions, the large volumes of water used made it impractical to achieve

values above 3 ppt in the test facility. Therefore, the holding tanks were

maintained at 3 to 5 ppt to obtain conditions similar to those in the test

facili ty.

Monitoring of pH , ammonia nitrogen, dissolved oxygen, and salinity was made

in order to maintain good water quality. A 10% to 25% water change was made

frequently as part of routine maintenance.

The striped bass and white perch were fed two to four times a day depending

on their acceptance of feed which was contingent on water temperature.

temperature decreased and the fish became lethargic, the number of feedings

decreased. The bass and perch were fed ground frozen squid, ground euphausid

shrimp, or frozen brine shrimp. The Atlantic menhaden were fed dry flake

food 4 to 6 times a day depending on water temperature.
The striped bass and white perch were collected from the Hudson River by

Texas Instruments, Inc. They were held at the Indian Point fish hatchery

prior to transport to ARL by S&W personnel.

Striped bass were obtained in two batches (3501 fish) in November and December 1978. OVer the course of testing, fish lengths ranged from 6. 6 to 12.

cm. Whi te perch were obtained in two batches; the first in October and the

second in November 1978. A total of 3811 fish were delivered. Lengths

ranged from 5. 1 to 9. 2 cm.

A total of 4500 Atlantic menhaden were collected and were transported from

Buzzards Bay, Massachusetts, by Sea Plantations, Inc. of Salem, Massachusetts. They were held at Salem prior to shipment by Sea Plantations to ARL.

While at Salem, the menhaden were conditioned to accept artificial food and

the salinity was gradually lowered from 28 ppt to a level of 3 to 5 ppt.

Menhaden were shipped in August and September 1978. The fish ranged in length

from 3. 9 to 8. 0 cm over the course of the study. During the course of the

study, it was sometimes necessary and desirable to reuse fish which had been

previously tested , where the category "previously tested" includes fish used

for any purpose, i. e., test or control individuals. During a test period,

all fish utilized for testing purposes were subsequently placed in a separate

tank and were never used further unless, or until, all untested fish had been

utilized. At times, the number of fish available for testing was small , and

it was, therefore, desirable to make use of these previously tested fish to

expand the data base. Previous studies have shown that testing fish several

times does not influence test results (Stone & Webster, 1976c).

port , all tests with previously tested fish are identified.

In this re-
TABLE 2.

Collection Data

Species Total No. Collected Length Range (cm)

Alewife

Striped bass

27, 000

501

9 - 12.

6 . 6 - 12. 

White perch

Menhaden

811

500

1 -

9 -
... 

FIGURE 2. FISH HOLDING FACILITY
SECTION 3

ANGLED SCREEN TESTING - SALT WATER TEST FLUME
SECTION 3

ANGLED SCREEN TESTING - SALT WATER TEST FLUME

In troduction

From July 1977 to March 1978, ESEERCO sponsored studies designed to optimize

the angled screen system. The saltwater test flume and angled screen test

device incorporated all of the structural details which would exist in a power plant system.

As previously discussed, past angled screen studies had yielded diversion

efficiencies of nearly 100 percent at an approach velocity of 1 fps and a

screen angle of 25 degrees to the flow (Stone & Webster, 1976a and c, 1977a

and b). These results indicated that higher velocities and greater angles,

both of which would reduce the cost of an angled screen system in a power

plant, might also yield acceptable diversion efficiency. Accordingly,

veloci ty and angle were the primary variables of interest in the ESEERCO

study.

The test parameters given below were selected on the basis of previous results and input from the member utilities of ESEERCO:

Approach Velocity

Screen Angle (deg. 1. 0 fps 2 . 0 fps

Menhaden

Menhaden

Striped bass

Whi te perch

Striped bass

Whi te perch

In addition, two tests were conducted with striped bass and white perch,

respectively, at an angle of 25 degrees and a velocity of 1. 0 fps for

comparison to previous studies (see Table 1. 1).
Description of the Facility

Diversion studies were conducted using 3/8 inch wire mesh screens mounted

on steel supports similar to prototype screen panels. The screens were

mounted in a 6 ft wide flume at an angle of 25 or 45 degrees to the direction of flow. The test screens were 13 ft 1/8 inch and 7 ft 9-3/8 inches

long at angles of 25 and 45 degrees, respectively. At both angles, the

screen led to a 6 inch wide bypass channel. A water depth of 6 ft was maintained for all tests. The test facility is shown in Figures and 3.

A diesel powered pump located in the return line circulated water through

the flume. The flow entered the 35 ft long test section through a flow

straightener and upstream containment screen. The flow was divided at the

test screens such that the velocity in the bypass channel was approximately

equal to the veloci ty in the approach channel. The operating speed of the

pump controlled the velocity in the test section, while gates proportioned

the flow between the bypass and the screens. The bypass channel expanded to

form a collection area. The fish remained in this area while the flow exited at low velocity through a containment screen. The collection area incorporated a lift basket to remove bypassed fish while the test progressed.

Prior to the start of each test , there was no flow while the fish were acclimating to the flume. At the start of a test, the flow was increased to

the desired condition by bringing the diesel pump speed to a predetermined

setting. A traverse of velocity measurements was obtained in the approach

and bypass channels at the conclusion of each test.

Velocity data indicated that the flow in the approach section was distributed nearly uniformly at a cross- section 10 ft upstream of the angled screen.

A traverse of velocity measurements obtained 4 inches upstream of the screen

face indicated velocities of the same magnitude and direction as those in

the upstream cross-section.
Biological Testing Procedures

From August 1978 through March 1979, Atlantic menhaden Brevoortia tyrannus

white perch, alewife, and striped bass were tested in the salt water test

flume. A summary of the test program is given below.

Species Length

()

Test Period Salini ty (ppt)

Atlantic menhaden August - October

Whi te perch 1 - October - February 0 or

Alewife 12. November

Striped bass 6 - 12. December March 0 or

Prior to the start of each test, 100 to 200 fish of a single species were

transferred from the stock pools to the flume. Fish were seined and dipnetted into buckets for transportation to the flume. A separate group of

control fish were simultaneously placed in a holding tank.

Before the introduction of fish to the flume, a removable fish crowder was

placed approximately 5 ft downstream of the upstream containment screen to

restrict fish movements during acclimation and thereby prevent premature

entry into the bypass. Fish were then placed in the flume and the lights

turned off. Fish were allowed approximately 15 minutes for acclimation to

the darkened conditions. As the flow was initiated, the crowder was simultaneously removed so that the fish could orient to the flow without contact

wi th the crowder. Tests were conducted in the dark to simulate conditions

which would occur in power plant intakes where low light (or no light) conditions, and possibly high turbidity, would largely preclude visual response

to an angled screen.

During each test , the fish collection area was checked hourly and all fish

present were removed to holding tanks. The screen was also checked (with dim

light) for impingement, but impinged fish were not removed until the completion of the test. These fish were included in calculations of diversion efficiency. Tests were conducted under artificially darkened conditions and
generally ran until the majority of the fish had been bypassed (approximately

4 to 7 hours after start of the test). Fish were removed from the bypass collection area with a lift basket device, netted into buckets, and transferred

to a holding tank for observation of daily mortality to 96 hours. Non-bypassed fish (those still swimming in the flume) were removed from the flume at

the end of the test , but were not held for mortality studies; however , they

were included in calculations of efficiency.

The tanks used to hold test and control fish for mortality studies consisted

of plastic cylinders, 3 ft across by 2. 5 ft deep, with nylon netting covering

the bot toms. The tanks were submerged to a depth of at least 2 ft.

For 96 hours following each angled screen test, all test and control tanks

were checked daily and dead fish were removed and recorded by tank.

Environmental factors recorded at the beginning and end of each test included

test flume and holding pool temperatures, dissolved oxygen concentration , pH,

salinity, conductivity, ammonia-nitrogen level , and time of day.

test, the approach velocity and bypass velocity were measured.

For each

Analytical Results

Fifty-eight tests were performed: 13 tests with menhaden, 4 tests with

alewife, 24 tests with striped bass, and 17 tests with white perch. Angled

screen test parameters and results are summarized in Table Five tests

were omitted from the statistical analysis. Alewives were not originally

included in the scope of the angled screen study. However, since they were

available at a time when other species were not being tested, four tests

were run to make use of available fish and time. While the results of these

tests are presented in Table 3. , they were not included in the data analysis. In general , the results were consistent with those from past alewife

diversion studies (see Table 1-1). In addition to the alewife tests, one

menhaden test (no. 6) was eliminated from the analysis. Water in the test
flume had been changed just prior to the test resulting in a high chlorine

concentration. Therefore, it is believed that the chlorine exposure during

a period of increased respiratory activity (swimming) led to the high mortali ty observed.

Therefore, 53 of the 58 tests conducted were subjected to statistical analysis. The angled screen was tested at angles of 25 and 45 degrees to the flow

under a variety of environmental conditions. The environmental variables

which would naturally fluctuate during testing of the angled screen included

species, water temperature, salinity, and pH. As stated above,. tests with

three species were analyzed. During the study, the water temperature in the

test flume ranged from OO C to 23. Oo The salinity of the water was either

a ppt or approximately 3 ppt, depending on test species. The pH ranged from

0 to 7. Approach velocities of 1 fps and 2 fps were tested. The summary

statistics for the three species are presented in Table 3.

The criterion for success of a device in diverting fish without damage or

stress is the Total Efficiency (E ). It is a combination of the efficiency

(E) of the device in diverting fish into the 6 inch wide bypass (which was

typically 100 percent) and the mortality (m), which is attributable to the

passage through the system. The functional relationship is summarized as:

T = E (lNumber Bypassed where E = (No. Tested) - (No. Non-Bypassed)

The mortality attributable to the system is determined by comparing the mortality of the test fish diverted (M ) to a control group of fish 

). 

The

only difference between the test fish and the control fish was the passage

of the test fish through the system which also involved additional handling

during collection. Previous studies indicated that removal of fish from the

collection area did not influence mortality. Therefore, in order to expedite

testing, control fish were not placed in and recovered from the collection
area. The differential mortality (m) is:

m=M -M

The differential mortality is assumed to be zero when the mortality of the

control fish is greater than that of the test fish mortality.

The test results were statistically analyzed by an analysis of covariance.

An analysis of covariance enables the inclusion of categorical and continuous independent variables and is, therefore, a blend of an analysis of

variance and a regression analysis. This type of analysis was chosen to

conform to the experimental design. The computer program used for the analysis of covariance was a least-squares procedure which allows an unequal number of observations per cell (Kemp, 1972).

The dependent variable used in the analysis was the total efficiency. The

categorical independent variables included batch, previous use, species,

and screen angle. Since white perch and menhaden were delivered to the

laboratory on two dates, the variability introduced by possible differences

in date of delivery was analyzed by the batch variable. The covariates inc luded approach velocity, water temperature, salinity, and pH of the water.

Interactions of the independent variables were also included. The analysis

of covariance enabled the simultaneous testing of independent variables.

Thus, it was possible to investigate the relationship between the dependent

variable and a single independent variable corrected for the effects of the

other independent variables.

The results of the angled screen analysis are presented in Table 3. The

rejection level of the null hypothesis for each source of variability is

also presented. Based on convention in fisheries science, independent

variables and/or interactions which had an a ~ 0. 05 were considered significant.
The angled screens were so highly efficient that there was very little variability in the data (refer to Table 3. 1). In 50 of the 53 tests analyzed

diversion efficiency was 100 percent. Total efficiency ranged from 72 to

100 percent with a mean of 96 percent and a median of 98 percent over all

conditions tested.

Based on the analysis of covariance (Table 3. 3), Total Efficiency seemed

to be influenced by species and the salinity of the water. The striped

bass was the most effectively diverted species (97. 8 percent; s. d. = 5.

and white perch was the least effectively diverted species (91. 8 percent;

d. = 6. 7). Menhaden were intermediate, with a total efficiency of 96.

percent and a standard deviation of 4. 04.

The salinity of the water also influenced the total efficiency. As the salinity of the water increased, the total efficiency of the device increased

as a result of lower latent mortality. As previously mentioned, alewives

were not included in this analysis. Al though there was an apparent relationship between efficiency and salinity, inspection of Table 3. 1 does not reveal

any substantial differences in efficiency at different salinities. Therefore

while the relationship is statistically significant, it does not appear to be

important.

Wi thin the range of independent variables examined , it appears that approach

veloci ty, angle of the device, gpecies, water temperature, previous use,

batch, and pH of the water did not significantly affect total efficiency.

The data were partitioned by species and analyzed by t-tests to clearly study

the relationship between the dependent variable and certain independent variables. Menhaden were studied to determine if the angle of the screen influenced the total efficiency, while striped bass were studied to determine the

relationship between approach velocity and total efficiency. The environmental variables (pH , salinity, and flume temperature) were not included in

these analyses since , wi thin each species, the pH , salinity, and flume temperature did not seem to vary siqnificantlv (refer to Table 3. 2)-
The results of the analyses indicated that screen angle did not influence

the total efficiency for menhaden tests. The total efficiency (and standard deviation) of tests conducted at 25 and 45 degree angles were 96. 2 I

3 and 97. 3 I 4. , respectively. Since menhaden were only tested at an

approach velocity of 1 fps, the results do not apply to the relationship

between total efficiency and angle at 2 fps.

Striped bass were tested at both approach velocities and, therefore, were

studied to determine the relationship between approach velocity and total

efficiency. Data indicate that the approach velocity does not influence

striped bass total efficiency of the device. The total efficiency of tests

conducted at 1. 0 and 2. 0 fps were 98. 9 I 1. 1 and 97. 1 I 7. 36, respectively.

These results also indicate that the tests conducted at 2. 0 fps were more

variable than those tests conducted at 1. 0 fps. Although the total efficiency of striped bass tested at 2. 0 fps ranged from 72 percent to 100 percent, only one test had a total efficiency less than 95 percent.

wi th respect to white perch, mean total efficiency of the screen appeared

higher at 2. 0 fps than at the 1. 0 fps velocity, averaging 97. 0 percent and

91. 7 percent , respectively.

In conclusion, the test results indicate that , within the range of variables

studied, species differences in total efficiency were significant; however,

these differences were not substantial. On the average, 98. 0 percent of the

fish (all species) were diverted efficiently. In addition , the salinity of

the water appeared to influence total efficiency, with efficiency increasing

as salinity increased; however, this relationship did not appear to be importanto
TABLE 3.

ESEERCO Angled Screen Results

96-HOUR ...J

...J

;;

96-HOUR TEST CONTROL ...J -:t 0.. -:t f- ~

)

0 )- MORTALITY MORTALITY -:t f- f- f- U -:t z - a: Z 0.. a:: ci: ci: w...J

:!: 

a: -:t :J ~ II) w f- 0 ~ 0.. Z 0 0.. Z 0 ...J ...J 0::(

~ 2 ~

...J 0::( 0::( u. a: J: u. ~ 0 0.. ...J 0::( 0 w 0 w a: - w W u.

en Z J: Z 0 0.. f- 0 Z J: Z 0 0.. f- 0 0:2 '" w

Menhaden 1.0 20. 200 171 171 006 100 100

Menhaden 1.0 20. 205 184 184 000 100 100Menhaden 1.0 23. 221 212 212 014 100 100

Menhaden 1.0 22. 205 177 177 100 100Menhaden 1.0 21.0 214 191 191 100 100

Menhaden 1.0 16. 200 170 170 100 I\.) Menhaden 1. 0 17. 204 195 195 100 f-'

Menhaden 1.0 18. 200 182 181 100Menhaden 1.0 17. 200 189 189 100

Menhaden 1.0 17. 200 187 186 100

Menhaden 1. 0 12. 200 182 179 100

Menhaden 1. 0 12. 209 187 186 100 100

Menhaden 1.0 15. 207 188 188 100

Whi te perch 1.0 13. 200 156 155 100 White perch 1. 0 12. 204 178 178 100 100 White perch 1.0 12. 208 188 188 100

17* Alewife 1.0 148 134 134 10018* Alewife 1.0 200 195 195 100

19* Alewife 1.0 200 197 197 100

20* Alewife 1.0 200 198 198 100

White perch 1. 0 100 . 91

Striped bass 1. 0 200 102 100

White perch 1.0 1. 8 100

Striped bass 1.0 1. 7 200 149 100 100

White perch 1.0 100
TABLE 3. 1

(continued)

96-HOUR

...J

;;

96-HOUR TEST CONTROL ...J ...J f- ~

:2 rJ) MORTALITY MORTALITY

;.

;.

rJ) f- f- f- U

;.

Z -

;.

a: Z rJ)

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;

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;:

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White perch 1.0 1.6 100

Striped bass 1.0 1.9 200 175 175 006 100 100

Striped bass 1.0 1.2 200 188 188 100

Striped bass 1.0 200 112 100Striped bass 1.0 224 166 100

White perch 1.0 100

White perch 1.0 100 I\.) I\.) White perch 1.0 100

Striped bass 1.0 200 146 100 100

Striped bass 200 179 179 100 100

Striped bass 200 165 165 100

Striped bass 200 159 158 006 100 100

Striped bass 200 169 169 006 100 100Striped bass 200 174 174 006 100 100

Whi te perch 100

Whi te perch 100White perch 100Whi te perch 100Whi te perch 100

45** Striped bass 200 190 190 100 100

46** Striped bass 200 192 192 100 100

47** Striped bass 200 170 170 100

48** Striped bass 200 196 196 100

49** Striped bass 200 169 169 100

50** White perch 1.8 100
TABLE

(continued)

96-HOU R

13.

;;

96- HOUR TEST CONTROL oet D.. oet I- ~

::i: CJ)

::i: MORTALITY MORTALITY

;..

0;..

oet CJ) I- I-

;..

oet

I- U

;..

::i: z - II: Z CJ) CJ) D.. II: II: w oJ

::i: II: oet :J ~

::i: CJ) D.. z D.. Z WI- 0 U

CJ) II: ::::i oet oet u. II: oet , oJ 00 oet

D.. oet II: - w 0 w 0 w II: - w ~ 0 to u. CJ) CJ) ;::O CJ) Z I Z 0 D.. I- Z I Z 0 D.. I- o::i: en w

51** White perch 1.8 10052** Striped bass 1.0 200 139 100 100

53** Striped bass 1.0 200 156 100

54** Striped bass 1.0 200 151 10055** Striped bass 200 153 153 007 100 100

56** Striped bass 10. 200 128 128 016 100

57** Striped bass 11.0 200 110 100 I\.)

58** Striped bass 12. 200 127 100

Tota Eff~c~ency = Diversion x (1 - Differential Mortality) , where Differential Mortality =

Test Mortality minus Control Mortality

*Not included in analysis.

**previously tested fish.
Species

TABLE 3.

Summary Statistics

No. Tests Velocity Range

Mean T (T ) (n) Angle (fps) ('X) E

1. 0 89-100 97.

1. 0 93- 100 96.

1.0 85- 100 91.8

1.0

73-99 91.9

1. 0 97- 100 98.

1. 0 100

72- 100 97.

Menhaden

Whi te Perch

Striped Bass

Total n = 53

Test #6 and tests 17-20 (alewife) not included in analyses.

TABLE 3. 3

ANCOVA - Angled Screen Study

Full Model

Sum of Mean

Source of Variation Squares Squares F Ratio a prob.

Species 325. 162. 0042*

Batch 6257*

Angle 6913

Previously Tested 7491

Velocity 5486

Flume Temperature x Species 97. 48. 1.88 166

Flume Temperature 16. 16. 4238

Salini ty 128. 128. 031 *

79. 79. 11 088

Error 1063. 25.

Total 2007.

*Significant since a ~ 0.
:IJ

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PUMP

FLOW

SCREEN PANELS

FLOW

BYPASS CHANNEL

BYPASS COLLECTION AREA

FIGURE 

...

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FLOW STRAIGHTENER

SALT WATER TEST FACILITY WITH 250 ANGLED SCREEN
"T1

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SECTION 4

ANGLED BEHAVIORAL BARRIERS

In troduction

From October 1978 to March 1979, a study was conducted to determine the

effectiveness of angled behavioral barriers in diverting juvenile striped

bass, white perch, and menhaden to a bypass. The use of such barriers has

been suggested for bypassing fish within power plant screenwells. The

mode of action is, therefore, di version, as compared to the barriers described in Section 6, which are designed to deter fish passage. The barriers investigated included hanging chains and water jet curtains (Figures

1 and 4. 2). The study was conducted in the salt water test flume with

the barriers set at 250 to the flow leading to a 6- inch wide bypass. Approach and bypass velocities were equal and were set at 1 fps in all tests.

Description of the Facility

Angled behavioral barrier testing was conducted by installing hanging chains

or water jets in place of the 25 degree angled screens in the salt water

test facility. The facility was operated in the same manner as it was for

the angled screen testing.

The angled barriers led to the same six inch wide bypass and collection area

as used in the angled screen testing. In addition , an inclined screen led to

a second collection area downstream of the test device to collect fish which

penetrated the barriers.

The hanging chain barrier consisted of vertical lengths of 3/16 inch chain

mounted at 2 inch intervals and supported above the water surface. The

lower ends of the chains were attached to a rod which extended to the bypass.

This allowed the chains to move with the flow without being carried into the

bypass channel.
The water jet curtain test device was constructed of eleven 3 inch diameter

vertical pipes, each separated by a 10 inch open space. The water jets are

produced by a row of 1/16 inch holes drilled every 1/2 inch along the length

of each pipe below the water surface.

the direction of flow.

These nozzles were oriented 550 to

The operation of the water jets caused a non-uniform flow through this barrier. The orientation of the jets produced a force across the flume which

concentrated the approach flow into the bypass side of the flume. An eddy

was formed behind the barrier with flow directed upstream at the side of

the flume opposite the bypass. This flow pattern produced high velocities

in the flow along the wall approaching the bypass and through the downstream sections of the barrier.

Flow for the barrier was supplied by a 40 HP pump which fed each vertical

pipe from above through a manifold. The flow was controlled by a valve

and adjusted to provide a 60 psi gauge pressure in the manifold.

Biological Testing Procedures

Testing of juvenile menhaden, white perch, and striped bass was conducted

from October 1978 to March 1979. A summary of the testing program is given

below:

Species Length (cm) Test Period

6 - October

October - January

4 - 12. December - March

Menhaden

Whi te perch

Striped bass

Biological testing procedures for the angled behavioral barriers were essentially the same as for the angled screen testing, with the exception that

bypassed fish were not held for mortality studies. Fish which had passed

through the barriers were subsequently diverted to a surface collection net

and enumerated.
SECTION 4

ANGLED BEHAVIORAL BARRIERS
Water quality of the flume was monitored for each test. Parameters recorded included pH , dissolved oxygen , salinity, and temperature. Approach and

bypass velocities, along with the start/stop time were also recorded for

each test.

Resul ts

The results of behavioral barrier testing are presented in Table 4. 1. With

the exception of menhaden tested at warmer temperatures (14. 8 to l6. C),

the chains and water jet curtain did not effectively divert the test fish

to the bypass under the conditions tested. It is not possible to draw

firm conclusions on water jet curtain efficiency due to the small number

of tests conducted. However, visual observations clearly showed that the

test fish did not respond to the water jets.

Hanging chains appeared to be more effective in diverting menhaden to a bypass than water jets. Mean percent diverted and standard deviations for

hanging chains and water jets were 74. 8 111. 8 and 15. 2 11. 7, respectively

(Table 4. 2). A t-test indicated that the results were significantly different at a ~ 0. 05. However , only three tests were conducted with the

water jet curtain (two with menhaden and one with white perch), since visual

observations showed that fish did not react to this barrier. Those relatively few fish which entered the bypass never approached the water jets but

rather followed the flume wall directly into the bypass.

Table 4. 2 also presents the summary results of the striped bass and white

perch testing. With respect to the chains, mean percent diverted and standard deviations for striped bass and white perch were 40. 0 114. 1 and 18.

110. 7, respectively.
In summary, with the exception of menhaden, it does not appear that hanging chains or water jets are effective barriers in diverting fish to bypasses under the conditions tested. It is conceivable, given the moderate

success with menhaden, that hanging chains could provide some assistance

in diverting other species of fish to bypasses. However, additional studies over a wider range of temperatures would be necessary to quantify the

effectiveness of this device.
TABLE 4. 1

ESEERCO Behavioral Barrier Test Results

Salt Water Facility

No. No.

Test Temp. Salinity Fish No. Through No. Percent

No. Barrier (ppt) Species Tested Swimmlng Barrier Diverted Di verted

Chain 14. Menhaden 200 114 62.Chain 14. Menhaden 200 143 77.Chain 16. Menhaden 200 132 85.

Chain 11. 2 White Perch 200 32.Chain 11.6 White Perch 204 26.Chain 12. White Perch 200 13.Chain White Perch 100 i-'

Chain Striped Bass 200 160 20.Chain 1. 3 Whi te Perch 100 10.

Water Jet 10. Menhaden 150 129 14.

Water Jet 11. 5 Menhaden 150 122 16.

Water Jet White Perch 100

13* Chain Striped Bass 200 46.

14* Chain Striped Bass 200 147 28.15* Chain Striped Bass 200 146 37.16* Chain Striped Bass 200 144 51.8

17* Chain Striped Bass 200 115 56.

*Previously tested fish.
TABLE 4. 2

Summary of Behavioral Barrier

Test Results by Species

Salt Water Facility

No. of Test Mean Mean Percent Diverted

Species Tests Device and Standard Deviation

Menhaden Chains 15. 74. :t 11. 79*

Menhaden Water Jet 10. 15. 1. 69*

Striped Bass Chains 40. :t 14. 11

White Perch Chains 18. :t 10. 72

White Perch Water jet

*Significantly different at a ~ 0.
6" 

BYPASS a

CHANNEL 

2" (TYP.

FLOW

J( 3/16" CHAIN

250

FIGURE 4. HANGING CHAIN DIVERSION BARRIER
16"

BYPASS

CHANNEL 1/2" TO FISH

COLLECTION

AREA

13- 1/2" YP,

NOZZ TERLES AT 1/2"

INTERVALS PI PES A LONG

3 INCH VERTICA

PIPES

FIGURE 4. WATER JET DIVERSION BARRIER
SECTION 5

FISH PUMPS
SECTION

FISH PUMPS

In troduction

Fish diversion systems, specifically angled screens, require a transportation system for returning fish to their natural environment. Because the

system must move fish from a lower to a higher elevation , a pumping unit

is required to supply the energy needed to overcome static and dynamic head

losses. Accordingly, two pump types were evaluated in the laboratory for

this purpose: a jet pump and a Hidrostal (screw impeller) pump.

Peripheral Type Jet Pump

Peripheral type jet pumps have been used to transport live fish in hatcheries. A program was designed to evaluate both the hydraulic characteristics of the pump and its ability to pass fish without injury under conditions which would simulate its operation within a power plant bypass system.

Description of the Facility

Testing was conducted using a peripheral jet pump mounted in an outdoor sump

(Figure 5. 1). In this type of pump, a high velocity jet is formed at a nozz le around the end of the 3 inch suction tube. The jet flow entrains water

from the suction tube and discharges through a 3-1/2 inch mixing tube. Hydraulic characteristics of this pump have been previously reported (Smith

1977) .

During testing, a 6 inch valve and flow meter controlled the flow through

an introduction box which was mounted to the pump suction tube. The pump

was located below the water surface allowing the mixing tube to discharge

directly into a netted collection area.

Figure 5.

The test facility is shown in
Biological Testing Procedures

Menhaden, alewives, white perch, and striped bass were tested in the jet

pump from September 1978 to February 1979.

gram is given below:

A summary of the testing proSpecies Length (cm) Test Period No. Tests Performed

Menhaden 3 - September - October

Alewives 7 - October

Whi te perch 6 - October - February

Striped bass 9 - 12. December - February

Eight of nine tests conducted with menhaden employed fish which had been

previously tested in other laboratory studies due to a limited supply of

this species. Similarly, 2 of 8 tests with striped bass and 4 of 13 tests

with white perch employed previously tested fish.

A seine was used to remove fish from the stock pools. Fish were then dipnetted into a bucket and transferred to the jet pump model for testing.

The test procedure consisted of placing 50 test individuals into the flume

upstream of the suction pipe and then crowding them toward the suction

pipe until they were pulled into and through the pump. Tests were conducted

at a jet nozzle velocity of 34 fps resulting in a suction pipe velocity of

about 8. 5 fps and a mixing tube velocity of 12. 3 fps.

Fish which passed through the pump were discharged into a rectangular collection area. Set into this area was a removable basket into which the

fish usually swam or were crowded. The basket was then lifted and floated

to the holding area.

tali ty 

Fish were held for 96 hours to determine latent mor-
Salini ty, dissolved oxygen, pH, and temperature of the holding pools and

flume were recorded for each test, along with the start/stop time. Holding

pool (tank) temperatures were generally different from flume temperatures

since the pools were located in a building while the test flume was outside.

To account for possible temperature effects on mortality, control fish were

held in the flume along with the test fish and were subjected to the same

handling except for actual passage through the pump.

Analytical Results

Observations during testing showed that all fish passed through the jet pump

without obvious signs of injury, stress, or disorientation. The results of

the testing program are presented in Table 5. Two alewife tests were conducted since this species was available at the time of testing. However

since alewife pump testing was not included in the scope of the ESEERCO studies, these tests were not included in subsequent analyses. However , the 100

percent survival values obtained were consistent with past pump tests with

alewives (Stone & Webster, 1977a). Therefore, while 32 tests were performed,

only 30 tests were analyzed by an analysis of covariance model (ANCOVA) to

study the relationship between the dependent variable, the percent mortality

after 96 hours, and the independent variables which would naturally fluctuate

during the operation of the device: species and temperature. The ANCOVA enabled the simultaneous testing of independent variables. Thus , it was possible to investigate the relationship between the percent mortality and species corrected for the effect of temperature.

The tank and flume temperatures were not included in the ANCOVA since the

temperatures were correlated with the species. If these temperatures had

been included in the analysis, it would not have been possible to separate

the effects due to temperature and species. Therefore, the temperature difference between the tank and flume (Table 5. 1) was used in the analysis.

A histogram of the mortality data (excluding alewives) from the entire testing period is presented in Figure 5. Graphical analysis of the residuals

indicate that a natural logarithmic transformation stabilized the variance

of the error terms and satisfied the statistical assumptions needed to perform ANCOVA.
The results of the jet pump analysis presented in Table 5. 2 indicate that

species and temperature difference significantly influenced the mortality

rate of the fish. It appears from the analysis that the mortality rates

increased as the temperature difference increased. However, the interaction between species and temperature difference was also significant.

Figure 5. 4 depicts temperature difference versus the observed mortality

rate (excluding alewives). The plot suggests that the three species are

influenced differently by the temperature difference. The mortality rates

of menhaden did not increase as the difference increased; the mortality

rates of striped bass appeared to decrease as difference increased; and

the mortality rates of white perch increased as the difference increased.

Since the species were not tested over the same range of temperature differences, the effect of temperature could not be statistically separated

from the effect of species.

Further analyses were conducted to study the mortality rates for each species. Descriptive statistics and histograms of the test and control mortalities for each species are presented in Figure 5. 5. White perch had the

highest average test and control mortalities followed by striped bass and

menhaden.

The distributions depicted in Figure 5. 5 are not normal and are quite different from one another. Therefore, non-parametric tests that do not require strict assumptions about the underlying distributions were employed.

The Wilcoxon signed rank test was performed to test for differences between

test and control mortalities for each species. These analyses indicated

that there was not a significant difference (p ~ 0. 05) between the test and

control mortalities wi thin each species.
Additional analyses were conducted to determine if the control mortalities

differed between species. The Kruskal-Wallis test, the non-parametric analog

to an analysis of variance (ANOVA), indicated that the control mortalities

for white perch were significantly different (p ~ 0. 05) than the menhaden

control mortalities.

In conclusion, the statistical analyses indicate that passage through the

jet pump did not stress fish. Al though the ANCOVA model found differences

between species, this difference was due, in part , to the mortality rates

from holding and handling.

observed for white perch.

The highest test and control mortalities were

Hidrostal Pump

In addition to the peripheral type jet pump, the Hidrostal (screw impeller)

pump was evaluated in the laboratory. This centrifugal screw impeller pump

had been used for pumping fish without damage in the processing industry and

for handling fruits and vegetables. To evaluate the potential effectiveness

of the Hidrostal pump, ESEERCO sponsored a study in 1978. Preliminary testing of menhaden, striped bass, and white perch, however, resulted in instantaneous mortality and high latent (96 hour) mortality (see Table 5. 4). Since

the Hidrostal pump tested had not been specifically designed for protection

of live fish , it was believed that a modified Hidrostal pump operating at

lower speeds (rpm) would offer better potential for fish survival. Thus,

a new Hidrostal pump was installed in 1979 and a testing program was conducted.

Description of the Facility

In 1979 , testing was conducted using a Hidrostal L12F pump. This pump has

a screw-type impeller which is contained in a shroud to decrease potential

of damaging fish. The intake and discharge pipes were 12 inch diameter.
The Hidrostal pump drew water from a sump through a netted fish introduction box. The discharge was directed upward to a collection area. The

12 inch discharge pipe was straight and included a plexiglass section for

observation of the fish. A containment screen in the collection area confined the fish while the water returned to the sump through a valve and

flow meter. The pump was driven by a variable speed motor. The facility

is shown in Figure 5.

The facility was operated by setting the pump speed and filling the collection area to the desired depth. The valve in the return line was then adjusted to match the inflow and outflow rates for that pump speed and net

head. The net head was the vertical distance between the water surface elevations in the introduction and collection boxes. By varying the depths of

water in the sump and collection box, the pump could be operated within a

range of net head from 10 to 16 ft.

Biological Testing Procedures

Juvenile alewives were tested from September through November 1979. Prior

to testing, a seine was used to remove fish from the stock pools. Fish were

dip-netted into a bucket and transferred to the Hidrostal pump for testing.

At the start of each test, 50 fish were placed in a specially designed introduction box and then passed through the pump which was operated at a

speed of approximately 430 rpm. Fish were discharged into a low velocity

head tank. The majority of the water in the head tank was then drained

and fish were dip-netted into a bucket and removed to a holding tank for

96 hours to determine latent mortality.

Control groups, each consisting of 50 fish, were placed in the head tank

removed by dip-net , and then placed in holding tanks for 96 hours. Temperature and water surface elevation of the tank and test flume were recorded for each test , along with the speed of the pump.
Results

Forty tests were conducted from September through November 1979. The length

of alewives tested ranged from 9. 9 to 10. 2 cm. Holding tank and flume temperatures ranged from 4. 7 to 22. C and 3. 8 to 21. C, respectively. Results

of the 1979 Hidrostal pump study are presented in Table 5. Mortality of

fish passing through the pump was very low, ranging from 0 to 10 percent.

Control mortality ranged from 0 to 4 percent. In the majority of the tests

(27 out of 40), 100 percent survival was obtained. Mean test and control

mortality were both 1. 25%. Since the mortality values and the variability

around them were low, statistical analyses were not deemed necessary.
TABLE 5.

Jet Pump Test Data

1978 Juveniles

Tank Flume Temp. No. 96 hr Test 96 hr Control Mortali ty Mortali t Test Salinity Temp. Temp. Diff. Fish

No. Species Tested No. Percent No. Percent

Menhaden 15. 15.

Menhaden 15. 14. 1.0

Menhaden 14. 14.Menhaden 14. 14.Menhaden 16. 15. 1.8

Menhaden 16. 15. 1. 7Menhaden 16. 15. 1. 7 I\.)Menhaden 17. 15.Menhaden 11. 8 10. 1.3

10* Alewives 11. 5 10. 1.011* Alewives 11. 5 10.

White perch 12. 10. White perch 12. 10. White perch 12. 10.

White perch 12. 10.White perch

White perch White perch

White perchWhite perch White perch White perch White perch

White perch
TABLE 5. 1

(continued)

Tank Flume Temp. No. 96 hr Test 96 hr Control

Test Salinity Temp. Temp. Diff. Fish Mortalit Mortali t

No. Species Tested No. Percent No. Percent

Striped bass striped bass Striped bass Striped bass Striped bass Striped bass Striped bass Striped bass

*Not included in statistical analysis.
TABLE 5. 2

Analysis of Covariance - Jet Pump

1978 Juveniles

Sum of Mean

Source of Variation Squares Squares F Ratio CI. prob.

Species 3. 844 1. 922 993 0154*

Temp. Differences x Species 580 290 547 0016*

Temp. Difference 663 663 918 0147*

Residual 238

Total 18. 981

*Significant since CI. ~ 0.

TABLE 5. 3

Test Data Summary

Jet Pump

No. of

No. of Range in Test Mean Test Control Mean Control

Species Tests Mortali ty

(%)

Mortali ty

(%)

Tests Mortali ty

(%)

Menhaden 2 - 20

White Perch 2 - 60 24. 25.

Striped Bass 4 - 28 15.
TABLE 5. 4

1978 Hidrostal Pump Data

(Whi te Perch, Striped Bass, Menhaden)

Temperature, 96 Hr Total

Mean No. Initial 96 Hr Test Control

Length Fish Mortality Mortality Mortali ty

Test No. Species Tank Flume (cm) Tested

(%) (%) (%)

Menhaden 17. 15. 18. 44.Menhaden 17. 15. 10. 34.Menhaden 12. 11.8 66.

Menhaden 12. 11.8 27.

Menhaden 11.1 26.

Menhaden 10. 22.Menhaden 10. 10.

Striped bass 42.

White perch 66.

Striped bass 16. 22.

White perch 36.

Includes initial mortality.
"TI

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())
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,(::0.

0 - 5 - 10 15 - 20 25 - 30 35 - 40 - 45 50 - 55 60 - 65 70 - 75 - 80 - 85 - 90 - 95-

9 14,9 19.9 24,9 29,9 34,9 39,9 44,9 49,9 54,9 59,9 64,9 69,9 74,9 79,9 84,9 89,9 94,9 99,

96-HOUR MORTALITY (PERCENT)

FIGURE 5. HISTOGRAM OF JET PUMP MORTALITY ALL SPECIES
60 I56 

MENHADEN

48 t-- WHITE PERCH

(!J STRIPED BASS

I--

40 

a..

I--

c:i

28 ~

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16 I12 t--

TEMPERATURE DIFFERENCE O

FIGURE 5.4 96 HOUR JET PUMP MORTALITY VERSUS TEMPERATURE DIFFERENCE

ALL SPECIES
MENHADEN TEST DATA MENHADEN CONTROL DATA

3 ~ MEAN 9, MEAN 6,

2 r- MEDIAN 8.0% MEDIAN 5,

n = 9 n = 6

:;:.

WHITE PERCH TEST DATA WHITE PERCH CONTROL DATA

L.U MEAN 24, MEAN 28.8%

MEDIAN 22, MEDIAN 28.0% III LI.. n = 13 I n = 5

L.U i-':2:

STRIPED BASS CONTROL DATA

3 ~ MEAN 9,

~.I

MEDIAN 10,

n = 3

STRIPED BASS TEST DATA

MEAN 15,MEDIAN 12,

n = 8

% MORTALITY

FIGURE HISTOGRAMS OF MORTALITY PARTITIONED BY SPECIES,

JET PUMP TESTS
RETENTION

SCRE EN

CUT AWAY VIEW OF

SCREW IMPELLER PUMP

COLLECTION

AREA

DISCHARGE PIPE

FLOW METER

WATER LEVEL

DIFFERENTIAL

VARIABLE

SPE ED

MOTOR

----w----

-~_w_--

FIGURE HIDROSTAL PUMP TEST FACILITY
SECTION 6

OFFSHORE INTAKE - BEHAVIORAL BARRIER STUDY
SECTION 6

OFFSHORE INTAKE - BEHAVIORAL BARRIER STUDY

In troduction

Beginning in the fall of 1975, studies were conducted for Niagara Mohawk

Power Corporation and Rochester Gas & Electric Corporation to determine the

potential effectiveness of behavioral barriers (air bubbles, hanging chains,

visual keys, and water jets) for reducing fish entrapment at offshore power

plant intakes. While it was known that such barriers would not prevent the

passage of all fish, it was believed that reductions might be achieved which

might warrant the installation of these devices in certain cases. The following is a brief description of the past studies that led to the ESEERCO

studies described later.

Preliminary studies involved exposing alewives and smelt to air bubble,

chain , and visual key devices placed perpendicular to the flow in a 3 ft

wide by 3 ft deep flume facility (refer to Table 1- 1). Resul ts showed

that none of the barriers significantly reduced passage relative to a

control condition (no barrier). However, since the flume did not incorpo rate escape routes which would exist at an offshore intake , the results

were considered inconclusive.

To better evaluate the barriers, a large offshore intake model was built

which more closely simulated field conditions. In this facility, visual

keys were dropped from consideration and a water jet barrier was added.

Tests were conducted with alewives and smelt. Variables included test device, intake velocity (0. 5, 1. , 2. 0 fps), number of fish tested (200, 400,

600, 800, 1 000), test species, water temperature (6. 7 to 26. 1 D C), and intake

segment. (Two intake segments were tested simultaneously in the model.

The results of the study were statistically analyzed and showed that significantly fewer fish were entrained into the intakes when the barriers were

in place (relative to a control). However, the individual barriers were not

significantly different from one another (stone & Webster , 1976b).
Testing with alewives, which was the primary test species, was conducted

at relatively warm water temperatures. Preliminary flume studies had indicated that the effectiveness of the barriers might decline at lower temperatures.

Accordingly, in 1978, ESEERCO sponsored an additional study to evaluate

the effectiveness of water jet, chain, and air bubble curtains at reduced

water temperatures. other test parameters were selected to be consistent

with the previous studies, described above.

Description of the Facility

Behavioral barriers were tested with alewives in a large outdoor basin, as

shown in Figure 6. The fresh water test facility included two segments

of an offshore intake structure, as shown in Figures 6. 2 and 6. 3. Each segment had a 5 by 2 ft opening which tapers to a 20 inch pipe. The pipe contained a pitometer for flow metering and discharged into a flow control and

fish collection area. The water passed over a control gate, through a fish

collection screen, and was returned to the sump which supplies the circulating water pumps. The pumps supplied water to screened areas upstream of

each intake segment.

The hanging chain barrier was constructed of vertical lengths of 3/16 inch

chain mounted at 2 inch intervals. The chains were hung at a level even

wi th the top of the intake and 1 ft 7 inches in front of the opening. Wing

walls were installed to extend the sides of the intake structure to the

chain barrier. This barrier is shown in place in Figure 6.

The air bubble curtain was produced by a 2 inch pipe mounted to the floor.

The pipe extended 3 ft 7 inches along both sides and across the face of the

intake. Wing walls were installed extending the sides of the intake inside

the air bubble curtain.

the intake.

The walls kept air from the barrier from entering
Air compressors supplied the barrier through a flow meter and control

valves. The barrier, shown in Figure 6. 5, consisted of a row of 1/32 inch

holes spaced every 1/2 inch along the pipe. The system was operated at a

flowrate of approximately 20 cfm free air and a pressure slightly greater

than the water pressure at the barrier depth.

The water jet barrier is shown in Figure 6. Five vertical lengths of

2-1/2 inch pipe were mounted at the face of the intake. The pipes were

sized to achieve uniform flows at all locations along the barrier. Each

pipe was drilled with two rows of 1/16 inch diameter holes spaced at 1/2

inch intervals. The water jets were produced at both sides of each pipe

at an angle of 600 to the approach flow.

Flow for the barrier was supplied by a pump which fed each vertical pipe

from above through a manifold. The flow was controlled by a valve and adjusted to provide a 60 psi gauge pressure in the manifold.

Biological Testing Procedures

The behavioral barrier devices were tested with alewives from August through

December 1978. Alewives ranged in length from 5. 9 to 12. 4 cmi mean length

was 8. 2 cm. The velocity at the intake face was either 0. 5 or 1. 2 fps.

Two tests were run simultaneously: one in each of two intake segments of

the model. Tests were conducted with each segment equipped with either the

hanging chains, the air bubble curtain, the water jet curtain, or without a

device as a control. At the beginning of each test, the desired flow was

set, and the appropriate hydraulic conditions were documented. After the

model flows were stabilized and the test was ready to begin, the temperatures of the holding pools and the model basin were recorded.

Fish were then removed from holding pools using a seine and a shallow dip

net. To minimize stress due to handling, no more than five to ten fish

were removed in anyone netting. These fish were then placed in 3 gallon

buckets and were transferred directly into the test basin by immersing the

bucket and allowing the fish to swim out.
During the first several tests, the number of alewives that entered the

intakes was recorded continuously. It was found that entrainment peaked

during the first few hours following sunset with few (if any) fish being

entrained during the daylight hours. In subsequent tests, therefore, the

collection areas were monitored at half-hour and quarter-hour intervals

(depending on the rate of entrainment in the collection areas), beginning

about one-half hour before sunset.

Da ta were recorded on the number of fish that entered each intake structure during each time interval. On a weekly basis, fish remaining in the

basin at the end of each test were left in the model and were considered

to be part of the total for the next test. This was necessitated by the

fact that it was not possible to drain the contents of the large test basin following each test and still complete the required number of tests

in the time available.

In general, up to four pairs of tests were run during each working week.

Tests were begun in the late afternoon and ran through the evening, lasting five to seven hours on the average. At the end of each working week

(Friday), water was drained from the model and all fish remaining in the

basin were removed.

A total of 44 tests were run: 12 air bubble, 10 hanging chain, 11 water

jet, and 11 control (Table 6. 1). Test velocities were 0. 5 fps and 1. 2 fps.

The water temperature ranged from 3. 9 to 12.

were utilized in each test.

Approximately 100 fish

Analytical Results

The results of behavioral barrier tests were statistically analyzed by an

analysis of covariance.

The percent of fish which passed through the intake was used as the dependent variable to correct for the differences in numbers of fish introduced

during each test. Results of previous analyses conducted by stone & Webster

indicated that under the conditions tested, the number of fish tested did

not significantly affect the number of fish entrained (stone & Webster,

1976) .
The categorical independent variables included the intake segment and the

behavioral barrier devices. The covariates included approach velocity and

water temperature. The interactions of independent variables were also

included in the analysis. Since the analysis of covariance enabled the

simultaneous testing of independent variables, it was possible to investigate the relationship between the dependent variable corrected for the effects of the other independent variables. Independent variables and/or

interactions which had an a 2 0. 05 were considered significant. Graphical

analysis of the residuals indicated that an angular transformation of the

dependent variable was necessary. The transformation stabilized the variance of the error terms and satisfied the statistical assumptions needed

to perform ANCOVA.

The analysis (Table 6 2) indicated that , as found in previous studies, the

use of behavioral devices significantly affected fish entrainment. The behavioral devices were effective in reducing fish entrainment; however, in

most cases, the individual devices did not differ significantly in their

relative performance.

The analysis of covariance accounted for 59 percent of the variability in

the percent of fish entrained. Based on the analysis, an average of 87

percent of the fish were entrained in the control segments, with a 95 percent confidence interval of 73 to 97 percent. In the segments incorporating

a water jet curtain , 59 percent of the fish were entrained on the average,

with a 95 percent confidence interval of 40 to 76 percent. The average percent entrained with an air bubble curtain was 56 percent with a 95 percent

confidence interval of 39 to 72 percent. Segments incorporating hanging

chains entrained 53 percent of the fish on the average with a 95 percent

confidence interval of 29 to 76 percent.

The behavioral barriers did not differ significantly in their relative performances at an approach velocity of 0. 5 fps. At 1. 2 fps, the rate of

entrainment with the hanging chains was significantly greater than the entrainment rates recorded for the air curtain and water jet at this velocity.

Overall, the percent of fish entrained was greater at 1. 2 fps than at 0.

fps.
In conclusion, the test results indicate that, within the range of variables studied, a water jet curtain, an air bubble curtain, and a hanging

chain barrier reduce fish entrainment in a model intake relative to a control situation. An average of 56 percent of the fish were entrained when

the behavioral barriers were used as compared to 87 percent without a device (control). Therefore, while the reduction in entrainment was significant with the use of the behavioral barriers, more than 50 percent of

the fish were entrained.

Veloci ty was the only significant covariate. Although the number of fish

entrained increased at the higher velocity, a larger volume of water passing through the intake per unit of time might be responsible for the increased rate. It was not possible to separate the effects of flow and

velocity since velocity increases proportionally to flow into an intake

opening of fixed si ze . Previous studies (Stone & Webster, 1978) which were

conducted speci fically to address differences in flow and velocity indicate

that the total flow volume entering an intake may be a more important factor in fish entrainment than velocity.
TABLE 6.

Offshore Intake Model

1978 Behavioral Barrier Test Results

Alewives

Wa ter Temp.

No.

Test Intake Intake Test Fish No. Fish Percent

No. Segment Tank Model Velocity Device Tested Entrained Entrained

11. 7 1. 2 Control 250 245

11. 7 1.2 Chains 250 231 92.

10. 1. 2 Chains 100

10. 1. 2 Control 100

11.1 10. Chain 100

11.1 10. Control 100

12. 10. Air bubble 100

12. 10. Chains 100

Water jet 145 30.

Air bubble 145 30.

10. Water jet 100

10. Air bubble 100

10. 1. 2 Water jet 100

10. 1. 2 Control 100

Control 100

Water jet 100

1. 2 Air bubble 100

1. 2 Water jet 100

10. Control 100

10. Water jet 100

10. 1. 2 Chains 100

10. 1. 2 Air bubble 100

10. 1. 2 Air bubble 100

10. 1. 2 Chains 100

Air bubble 100

Chains 100

1. 2 Water jet 100

1. 2 Air bubble 100

Chains 100

Control 100
TABLE 6.

(continued)

Wa ter Temp.

No.

Test Intake Intake Test Fish No. Fish Percent

No. Segment Tank Model Velocit Device Tested Entrained Entrained

8. a 1. 2 Control 100

1. 2 Water jet 100

1. 2 Chains 100

1. 2 Air bubble 100

10. Water jet 100

10. Control 100

7. a 6. a Chains 100

6. a Air bubble 100

Air bubble 100

Water jet 100

1. 2 Control 100 103 100

1. 2 Water jet 100

1. 2 Air bubble 100

1.2 Control 100
TABLE 6.

ANCOVA - Behavioral Barrier study

Sum of Mean

Source of Variation Squares uares F Ratio CI. Prob.

Segment 262. 262. 51 1.132 2967

Device 3, 246. 08 082. 667 0094*

Segment x Device 246. 188. 812 4982

Velocity x Device 234. 78. 377 O. 7986

Temperature x Segment 535. 535. 310 1402

Temperature x Device 096. 365. 1. 577 2179

Velocity 958. 958. 132 0520*

Temperature 71.16 71.16 307 O. 5842

Residual 260. 231. 86

Total 14, 244.

*Significant since CI. .::: 0.

Mean Percent of Fish Entrained Per Test

Corrected for Effects of Other Variables

(Predicted from ANCOVA)

Device

Mean Percent

per Test

Control 86.

Wa ter jet curtain 59.

Air curtain

Hanging chains

55.

52.
't:

I:c

..,,,

FLOW

PUMPS

FIGURE 6.

!!!:,

r------ 

:,

SCREENS 

27.5' 

.,. 

INTAKE

SEGMENTS

'0\

.1- o.

. , . 

-, 'I

1\1

,,. , 

FLOW CONTROL AND

FISH COLLECTION AREAS

PLAN VIEW

OFFSHORE INTAKE TEST FACILITY
FISH COLLECTION

SCREEN

ADJUST AB LE

HINGE GATE

PI TOT TUBE

FLOW METER

20" DIA,

FLOW

FALSE FLOOR

INTAKE

STRUCTURE

OW CONTROL & FISH

COLLECTION AREA 10' 10'

SECTION AFIGURE 6. INTAKE SEGMENT STRUCTURE FOR TESTING BEHAVIORAL BARRIERS

TEST

r DEVICE ---r

24"

12"

~O I

0'1l.J

REMOVABLE,WING WALL
(

)

"T1

!J'

)::0

0'\
. 

'\J

SIDE VI 

WING

WALL 3/16" CHAIN

FLOW

36"

....

FLOW

3/4"

.. 

"0.',

::

PLAN VIEW

FIGURE HANGING CHAIN BEHAVIORAL BARRIER

OFFSHORE INTAKE STUDY
SIDE VI EW

,:, ,,,::.... :::::::::::::,,:::,:;:: :::::::;::,::,::::,::::,:,:,: ::,:.:.::::::,,:.:::.:..::::. :.:.

FLOW

:.::,::::::,: ,::.:::.:.:.:..:::.:.y:::::::::::::::::::::: ::::::::::::::

;(1

PLAN VIEW

, , , , , , , , ,. , , , . , , , , , , . , , , , , 

FIGURE 6.

WING WALL

36"

BARRIER LOCATION

, : ,,, .... .... .... ....

FLOW

AIR BUBBLE BEHAVIORAL BARRIER

OFFSHORE INTAKE STUDY

1/32"

DIA.

1- 1/2"

(TYP,
SIDE VI 

::, ;,:,:::, :::::

"::i':.':::::::'::::':':"

.. :::;::::::.::::,::::;:;;::::::;::: .

FLOW

... .,.  

PLAN VIEW

FIGURE 

24"

1/2" (TYP,

1/2" PVC PIPE

. 

FLOW

1/16"

NOZZLES

WATER JET BEHAVIORAL BARRIER

OFFSHORE INTAKE STUDY
REFERENCES
REFERENCES

Conover, W. J., 1971 Practical Non-Parametric Statistics , John Wiley &

Sons, Inc.

Empire State Electric Energy Research Corporation (ESEERCO), 1981,

Laboratory Evaluation of Fine-Mesh Screening for the Protection

of Fish Larvae at Intakes, Prepared by Alden Research Laboratory

and Stone & Webster Engineering Corporation, May 1981.

Kemp, K.E., " Least Squares Analysis of Variance, A Procedure, A Program, and Examples of Their Use, " Kansas Agricultural Experiment

Station , Contribution 168, Res. Paper 7, 1972 , p. 26.

Smith, P. J., " Peripheral Jet Pump Study, " Alden Research Laboratory

Report No. 7l-77/M10UF, May 1977.

Stone & Webster Engineering Corporation , 1975a, Studies to Alleviate

Potential Fish Entrapment Problems - Summary Report , 1973- 1974

Efforts, Nine Mile Point Nuclear Station unit 2 , Prepared for

Niagara Mohawk Power Corporation, February 1975.

Stone & Webster Engineering Corporation , 197 5b, First Progress Report

- Indian Point Flume Study, Prepared for Consolidated Edison Company

of New York, Inc., August 1975.

Stone & Webster Engineering Corporation, 1976a, Studies to Alleviate

Potential Fish Entrapment Problems at Lake Ontario Power Plant Intakes, First Interim Progress Report , Prepared for Niagara Mohawk

Power Corporation and Rochester Gas & Electric Corporation, April

1976.

Stone & Webster Engineering Corporation , 1976b, Studies to Alleviate

Potential Fish Entrapment Problems at Lake Ontario Power Plant Intakes, Final Report, Prepared for Niagara Mohawk Power Corporation

and Rochester Gas & Electric Corporation , November 1976.
Stone & Webster Engineering Corporation, 1976c, Final Report - Indian

Point Flume Study, Consolidated Edison Company of New York, Inc.,

July 1976.

Stone & Webster Engineering Corporation, 1977a, Final Report - Studies

to Alleviate Potential Fish Entrapment Problems at Nine Mile Point

Nuclear Station, unit 2, Niagara Mohawk Power Corporation , Volumes

1 and 2 , May 1977.

Stone & Webster Engineering Corporation, 1977b, Studies to Alleviate

Potential Fish Entrapment at Unit No. 6 - Oswego Steam Station

Prepared for Niagara Mohawk Power Corporation, May 1977.

Stone & Webster Engineering Corporation , 1978 , Offshore Intake Veloci ty Study, prepared for Rochester Gas & Electric Corporation,

April 1978.