# llOGICALEVALUATION

# OF ANDLING 

# COMPONENTS 

# JATER INTAKE SCREEN !. 

# DESIGNEDTOPROTECT LARVAL 

# FISH

DivisionofWater

### Resources 

### TcnncssceVnllcyAuthority

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orris.Tc tinc:iscc 378

### 28A RIOLOCICAL 

### EVALUATION OF FISH HANDLINC 

### COMPONENTS OF A 

### WATER 

### IIiTAKE SCREEN DESIGNED 

### TO PROTECT LARVAL 

### FJSH



### Prepared by IldultI A. ~l~l~llll.~!l~lli?Jlt I1 

### John 

### H. Heucr

Division of Water Resourc-i!s

l’carlricssoc Vi111

### (’y AuLlioriLy



### Norris, Tennessee 37828 

### I

### ABSTRACT Larval fish survival associatedwith allaspects 

### of fish handling 

### on a laboratorymodel center-flow 

### screen was evaluated. The fishhandling components which were evaluated included: (1) impingement diiriition, (2)tritvc-1 rroin Llir air-wntcr intcrfncc to thc: spilling position, and (3) spillinginto a fish return trough. Relatively large larvae

### OC scvural 

### species (paddlefish, 

### iior!Aiern 

### pikc, wliitc 

### sucker, nnd ~~1~~!1~~1~.! condit ons. Two small, fragile larvae, striped bass and striped bass 

### x white bass hybrid, showed very low survival under nearly allconditions, while intermediate survivalwas exhibitedby the redbreast sunfish, largemouth bass, bigmouth buffalo, and walleye. Plultifactor analysis of variance of the results from 

### tests of four :;pecies showing intcrmediate survival showed that impingement dL,rationhad 

### the grcatest . 

### rc:il\fj?!l) 

### #!l'~yixl!![E!]

### yyiy!!! I!w!lpc 

### I!o!irly iI!

### 1 c!xl+ritiwni-ttl

.. effect on survival, followed by airexposure. Spilling appeared to have .. little effect 

### on survival. The important species and critical life stages of fish ata proposed intake

### will determine 

### both the biological feasibility of a prototype impinge-releasr rcrecn systcm and the extent 

# :

### iii

### A BIOLOGICAL EVALUATION OF 

### FISH 

### HANDLING COMPONENTS 01: 

### A WATER INTAKE 

### SCREEN 

### DESIGNED TO PROTECT 

### LARVAL FISH :I f 

### INTRODUCTION Investigations 

### of screening technologies toprotect fish at power plant cooling water intakes have been conducted by 

### TVA since 

### 1976. The aim of these studies has been todevelop screen systems capable of

.. 

## -.

. i , .. .., 

### .. .
,.:'I ** protecting allpost-hatch life stages. Since it is generally txue.that .- .4 .,
.. the larvae represent the most fragile phase of a fish's life cycle,
.. . these studies have concerned protection of these earliest life stages.

.. Screens which protect larvae willalso afford protection for ttir larger,



### .. 1 

### One screening concept 

### under invrstigation ~ses 

### contj nuoilsly 

### . I



# . moving fine mesh screens to filterthe fish from thewater as itpasses through the screens atthe intake pumping station. Following if short impingement time, which is dependent on screen travel .peed arid Lhr aniount of submerged screen, the fish are lifted from the water 

### in sc-rperl .. panels and spilled into a fish return trough which carries them back LO . the source water body. This "impinge-release" conccpt can be applicd to horizontal (submerged) as well asvertical (emergent) traveling screens. . Features common to each scrr'en include smal

### I opcniiig nicBsti, coriLiritic,i~s screen rotation to minimize impingement time. and provisioris to 

### rtturn the fish tothe source water body. ..

in 

### i976 a series of laboratory tests was conducted to evaluate the potential for this concept 

### (Tom1 janovich et al. 1976). 

### Tw+,ohjectivcs of that study were to: (1) determin? the srnallcst size srreeii opening ~it+c~ilrcl Lo reL;tiii Cisli lurviit!, 111111 (21 c~vri111riL~~ tht, !2iri;viv,iI rtitt- (11 I titretained, i.e., impinged, larvae. 

### The study showed that a scrCen ~prriing

### 2 of 

### 0.5 inn1 was requircd to 

### rc1L;tin 

### the 

### sniallest larvae 

### tested and that imI>ingeiiicnt durati-onsof up 

### to 

### four minutes rcsulted 

### in initial survival between 

### 75 arid 100 percerit. These 

### results suggested that the concept was viable ant1 that 

### future studies should 

### be 

### directed atdeveloping 3 prototype screen. Ol>j ertivcs

. ... . .- 

### - . 'I'iie piirpose of the present :;turly was to evaluate larval fish survival associatcti with a11 aspects cf fish h;iiid:irig on a laboratory 

# . screcsn. 'rht.sr data uil1 hc used to oplimizc xurviviil of fish by niodi.fying any components of thc screcn which cause significantniortality to thc 1.arvoe. 

### This report dcscribes ihr prototype screen wlii

### ch was ctiosc?nfor laboratory tests, the laboratory model 

### test scrt-clri, and the tc'st clcsigri. Italso prcsents thf. results of tests coridiicted during 

### 1978 arid icictntif.ics remaining areas of study that riced to be adrlrcssetf iri ortlcr todevclop a final prototype 4esign.showed very low stirviva1 

### with and without temperature control. 

### the refrigeration unit, very little useful information would have been obtained exrcpt 

### €or the ti;irdjr species. Without

SUM!lIARY 

### 1. Ten larval 

### fi.sh specics, ranging in age from 

### 3 to 

### 16 days and total length from 5.0-14.0 

### mm were tested in 

### 1977 and 

### 1078 on a laboratory model fine mesh traveling screen. The objective of the 

### test was to evaluate the effect of several fishhandling components (impingement, exposure to air, and-spillinginto a fish

### return trough) on survival of the larvae. 

### 2. No significant differences in effect of various fishhandling coiiiponents were shown for four relatively large, hardy species of larvae. Paddlefish, northern pike, white sucker, antl channel catfish, which were among the youngest (three to six days of age), but largest larvae showed high average initial and 24-hour survival 

### (>97 percent ancl >S9pel-cc!it

### , rt~spc~ctively) under all test conditjons.

.J. 9. 

### Two 

### specicis (striped bass antl striped bass 

### x white bass hybrid) showed relatively iow ;!vt?rage survival under most test condiLions

## , ~:>hicti .?lsr!preclutfed evaluating the effect of screen components on surviv;il

### . Con: r.oL survival for thcsc specics ais0 was low and tiiglily VAL-i gj tiit: 

### .

### 29 

### 4. Redbreast sunfish, largemouth bass, bigmouth buffalo, and walleye larvae showed survival intermediate between the other two groups. This intermediate group of four species was used to evaluate the fish handling components. The following items concern the intermediate group species: 

### 5. Impingement showed the greatest effect on survival and was significant '



### CONCLUSIONS The objective of this study was toprovide the necessary 

### information to identify components 

### of an impinge-release 

### screen system which need 

### to be modified in order to optimize fish survival. It wa!; obvious from initial results that the amount 

### of modification needed willbe dependent largely on the species and life stages to tic protected. 

### 6. 

### Air exposure had a significanteffect 

### on initial and/or 24-hour adjusted survival for allfour species. usually associated with least airexposure. Highest survival was


### 7. The effect of spilling fish into the return trough was not significant in

### tests which included airexposure for any 

### of the four species. In 

### tests which did not include airexposure ("impingement only" and "impingement plus spi.11from a wet

., screen") an apparent effect of spill was observed for three

. ..il species. 8. Two-way interaction effects among the three variables did not appear tobe important.

### 30 The large range 

### in survival among species tested suggests that 

### a similar pattern would 

### be found 

### inthe natural environment using a prototype screen. Consequently, an average survival rate for larval 

### fishwould not 

### be meaningful. species was related to size differences for a given age among 

### species. Much 

### of 

### the range 

### in survival among If a species that has relatively large larvae is tobe protected, little or 

### no modification tothe basic finemesh screenmay be needed. However, if small, fragile larvae, such as striped bass, require piotection, considerable modification may be required toprovide optimum protection. To date, tests discussed tiere have 

### shown only limited success inprotecting the very fragile species using this impinge-release concept. However, high control mortality 

### intests with these 

### species suggests that the 

### ._

...

:

.. laboratory studies have not adequately described the effect 

### of the screen 

### on survival.
.

..

. : 

### For species 

### of intermediate hardiness 

### it appeared that providing a water trough to the screen panel, limiting the impingement . time 

### to four mirutes 

### or less, and providing 

### low pressure sprays for fish renioval would significantly increase survival. Additional testing is required €or fragile tomoderately hardy species in order tu .~dequately identi.fythe need for and evaluate screen systcm modifi.cations. 

### Specific areas which need to

### be addressed include: (1

### j deterrni.ning optimum spray velocities and volumes, 

### (2) evaluating the effect of screen clc>g:gingon flow pattern as it may influence fish remcval and survival, and 

### (3)determining optimum screen panel configuration for ..

. ..



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