### -1-

RETENTION OF JUVENILE WHITE STURGEON, ACIPENSER TRANSMONTANUS, BY PERFORATED1/21 PLATEAND WEDGE-WIRE SCREENMATERIALS 

### -

## -

Harvey

### H. Reading 

## - 3/ Bay-Delta Fishery Project 4001 North Wilson Way

Stockton,CA 95205

ABSTRACT
The Fish Facilities Study,part of the Interagency Ecological Study Program for the Sacramento-San Joaquin Estuary, evaluated the potential of perforated plate and wedge-wire materials for screening juvenile white sturgeon ranging in size from 17.0 to 63.0 mm (0.7 to 2.5 

### in)total length (TIL). Experimental sturgeonhatcheries provided test fish �or the study. Evaluations employed various screen opening sizes and approach velocities as variables to determine their effects on screening young sturgeon. Sturgeon 27.0 mm 

### TL and longer were retained by 3.96 mm (5/32 in.) diameter perforated plate and 2.38 mm (3/32 in.)sfot width wedge-wire at 

### 6.1 cm/s (0.2 ftfs), the lowest approach velocity tested. Impingement of over 20%of the fish tested occurred at 6.1 cm/s,while at 18.3 cmls (0.6 ft/s) the highest approach velocity tested, total impingement occurred within 5 min.



## - 1/ This study was conducted as part of the Interagency Ecological Study Program for the Sacramento-San JoaquinEstuary whose members include: California Department of Fish and Game,California Department of Water Resources, U. S. Bureau of Reclamation, and 

### U. S. Fish and Wildlife Service.



### - 2/ Anadromous Fisheries Branch Administrative Report No. 82-6. Submitted March, 1982.



## - 3/ Current Address: Department of Fish and Game,P. 0. Box 607, Red Bluff, CA 96080.-2-

INTRODUCTION

Downstreammigrant sturgeonwill be exposed to the fish screens at the proposed Peripheral Canalwater intake near Hood, California. 

### It is necessary to determine how effectively juvenile sturgeon can be screened by.perforated plate and wedge-wire screenmaterials to help formulate a plan of protection for this species. Prior to this study, information regarding the screening of juvenile sturgeon was lacking,as they were not available in numbers sufficient for conducting a study program. In 1980,hatchery-reared juvenile white sturgeonwere obtained from the experimental sturgeon hatchery at the University of California, Davis, California.

. 

### In 1981, the Elk Grove-Florin Catfish Farm near Sacramento,' California provided test fish. Previous studies indicate that perforated plate with 3.96 mm (5132 

### in.) openings or wedge-wire screenwith 2.38 mm (3132 in.) width slots adequately protect juvenile chinook salmon,Oncorhynchus tshawytscha, and American shad, Alosa sapidissima. This study evaluated the effectiveness of these and other screen opening sizes to determine their potential for screening juvenile white sturgeon. To accomplish this goal, sturgeonwere exposed to these materials under controlled conditions using water approach velocity and screen opening size as variables.

METHODS The testing program was conducted during 1980 and 

### 1981 at the Fish ScreenTesting Facility at Hood, California. Pumps at the facility supplied unfiltered Sacramento River water for holding and testing juvenilewhite sturgeon ranging in size from 

### 17.0 to 63.0 mm TL (Table 1). a Transportation of juvenile sturgeon from the hatchery sources to the test facility, accomplished using ice chests lined with plastic bags containing aerated water, took less than 1-h per trip. At Hood, a 1-h acclimationperiod, during which SacramentoRiver water gradually replaced hatchery water 

### in the transport bag, preceded transferring the fish to a 757-1 (200-gal) circular fiberglass tank for holding prior to tests. Sacramento River water flowed Exclusive use of through the tank at approximately 35 l/min (3 gal/min). riverwater resulted in identical water conditions for both holding and testing young sturgeon. To provide the means for confining test fish in close proximity to the screen materials chosen for evaluation, tests were conducted in a 19.7 crn (7.75 in.) diameter transparent plastic cylinder, similar toone used by Fisher (1978). The cylinder was fitted with test screen discs of various opening sizes and was screened at both ends to prevent fish from escaping frmthe cylinder (Figure 1). Submerging the cylinder in ambient water with an adjustable rate of flow allowed selected water (screen approach) velocities inside the cylinder. Water velocity within the cylinderwas measured with a Gurleymode1-3-

TABLE 1. Average and Range of Total Lengths of Juvenile White Sturgeon at Various Test Parameters.

Approach Screen type Average total Range of total velocity P = Perf. plate length lengths

(cm/s> W = Wedge-wire (m> (mm>
6.1 P 31.3 19.0

## - 63.0 6.1 W 32.0 17.0 

### - 61.0 12.2 P 36.7 19.0 

## - 63.0 12.2 

## w 32.2 19.0 

### - 63.0 18.3 P 45.6 31.5 

## - 63.0 18.3 W 38.1 21.0 

### - 61.5

.-4-

C 

## 30 5: VI rn 0 rn .r( a C W W u V VI

a a, 3

rn W Y C 0 .rl

(u ? 3 r)560680pigmy current meter mounted inside the cylinder at its downstream end. Screendiscs,arranged in the cylinder in a stepwisemanner,presented test fish, initially placed in the upstream end of the cylinder, with screen discs having successively smallerhole sizes as they passed downstream through the cylinder. Test fish failing to pass through a disc at the end of a 3-h test were considered retained by the hole size associated with that disc. Tests during 1980 evaluated perforated plate hole diameters of 

### 6.35, 4.76,and 3.96 mm (lf4,3/16,and 5/32 

### in.). In 1981, testing w5t.h perforated plate included 3/96mm and 3.18 mm (118 in.)diameter holes. Tests during both years evaluated 3.18 and 2.38 mm (3/32 in.)wedge-wire slotwidths. Screen approach velocities evaluated were: 6.1, 12.2,and 18.3 cm/s (0.2, 0.4, and 0.6 ft/s) during both years. The test group size in 1980was 50 fishftesr, In 1981,with fewer fish available,the group size was 25 fishltest. Following a test at a given combination of screen type and approach velocity, each fishwas measured to the nearest 0.5 mm TL and the screen disc that retained that fishwas noted. Length data were grouped into 2-mm length-class intervals �or the various combinations of screen type,hole size,and approach velocity

# . In addition to retention data, records were kept of the number of fish impinged on the screen discs at the -conclusion of a test. This data allowed calculation of a simple regression equationwhich helped describe the relationship between approachvelocity and impingement.
RESULTS 

### No mortality was experienced during transportation of juvenile sturgeon from the hatcheries to the test facility at Hood. Perforated plate with 3.96 mm holes retained sturgeon 27.0 mm 

### TL and longer with an approach velocity of 6.1 cm/s (Table 2). At 12.2 cm/s, this samematerial retained sturgeon 29.0 mm 

### TL and longer. Sturgeon as small as 21.0 mm 

### TL were retained by perforated plate with 3.18 mm holes. During 1980evaluations,wedge-wire screenwith opening size of 2.38 mm retained sturgeon 27.0 m TL and longer at 6.1 cm/s, and at 12.2 cm/s thismaterial retained sturgeon 29.0 mm 

### TL. These results are similar to those obtained with 3.96 mm perforated plate. During 1981 evaluations, 2.38 mm wedge-wire retained sturgeon 23.0 rnm 

### TL at 6.1 cm/s and 25.0 mm 

### TL at 12.2 cm/s (Table 2). A strong positive relationship exists between screen approach velocity and impingement of juvenilewhite sturgeon (Figure 2). Impingement at each velocitywas similar for both perforated plate and wedge-wire material. At 18.3 cm/s,complete impingement of test fish occurred within 5 min.-6-



### TABLE 2. Total Lengths at Which Juvenile White Sturgeon Were 100% and 0% Retained at Various Combinations of Screen Type, Hole Size, and Approach Velocity.

Screen type Screen Approach

. 100% 0% Year wedge-wire 

### (W) (mm) (CRI~S) (IIBII 

### TL) (m

### TL)
1980 P 6.35 6.1 45.0 34.0 1980 P 4.76 

### 6.1 31.0 19.0" 1980 P 3.96 A. 1 27.0 19.0" 1981 P 3.96 6.1 27.0 19.0 1981 P 3.18 6.1 21.0 19.0 1980 P 6.35 12.2 43.0 33.0 1980 

### P 4.76 12.2 31.0 21 -0 1980 

### P 3.96 12.2 29.0 21

## .o 1981 P 3.96 12.2 25.0 19.0 1981 P 3.18 12-2 25.0 13.09: 1980 

### W 3.18 6.1 31.0 13.0;' 1981 W 3.18 6.1 29.0 '19.09: 1980 

### W 2.38 6.1 27.0 15.0 1981 

### W 2.38 6.1 23.0 19.0 1980 

### W 3.18 12.2 33.0 19.0 1981 

### W 3.18 12.2 33.0 23.0 1980 W 2.38 12.2 29.0 17.0 1981 W 2.38 12.2 25.0 19.0 perf-plate

### (PI opening velocity retention retention



# * Calculated values.-7

### -

Average Percent 

### Impin

### gement



### 50



## oi J/ I I 

## I 3 

### 2'- 

## 6-1 I!? 

### -2 18.3 Approach Velocity 

### (cm/s) FIGURE 2. Average percent impingement of juvenilewhite sturgeon on test screen discs at three approach velocities �or perforated plate 

## (A)and wedge-wire (0). A = Calculated line based on impingement results from 3 approach velocities. B = Line fit to the 2 points where impingement was less than 100%.-8-

DISCUSSION
Both 3.96 mm perforated plate and 2.38 mm wedge-wire effectively screen juvenile white sturgeon 

### 27.0 mn~

### TL and longer at approachvelocities of 6.1 cm/s and less. Juvenilewhite sturgeon as small as 10mm (0.4 in,.)havebeen collected in the Sacramento River downstream from Hood (Stevens and Miller 1970). Exptected losses forwhite sturgeon less than 27.0 mm 

### TL exposed to these screen opening sizeswould be high. The impingement results indicate that a significant proportion of white sturgeon in the size range tested fail to maintain their position against currents as low as 6.1 cm/s, over a 3-h period. A calculated approach velocity of no less than 2.3 cm/s (0.075 ft/s) appears necessary to completely prevent impingement (Figure 21, however additional testing should be conducted to more accurately determine acceptable approachvelocities. Additional studies are necessary to develop safe and effective criteria for screening juvenilewhite sturgeon. The location of juvenile sturgeon in the water column, their daily activity patterns, and their susceptibility to diversion into the Peripheral Canal .intakeare essentially unknown at this time; however,a benthic association is suggested by the literature (Stevens and Miller 1970;Kohlhorst 19761, and a sill at the base 

### of the intakehas been provided to reduce entrainment of benthic species. If it is determined that large-scale entrainment of young sturgeon is likely, then criteria for screen opening size and approach velocities should be considered.

ACKNOWLEDGMENTS SergeDoroshov,Department of Animal Science,University of California, Davis, and the staff of the 

### Elk Grove-Florin Catfish Farm supplied fish for testing. Ronald Lunsford and James Gibboney, California Department of Water Resources, provided engineering expertise and maintained the test facility. Alan Pickard and DanOdenweller, California Department of Fish and Game, designed the studies and provided support and editorial assistance. 

### To these, and especially to the seasonal employees associated with the study program, a great deal of gratitude is due.-9-

REFERENCES
Fisher,F. 

### W. 1978. Retention of young king salmon,American shad,and striped bass by perforated plate and woven-wire screens. Calif. Dept. Fish and Game, Anad. Fisheries Branch Admin. Rept. No. 78-18:19 pp. Kohlhorst, 

### D. 

### W. 1974. Sturgeon spawning in the Sacramento River in 1073,as determined by distribution of larvae. Calif. Fish Game, 62(1):32-40. Stevens,

### D. E., and L. 

### W. Miller. 1970. Distribution of sturgeon larvae in the Sacramento-San.JoaquinRiver system. Calif. Fish Game, 56(2):80-86.