Prepared in cooperation with the Chelan County Public Utility District

Capture of White Sturgeon Larvae Downstream of The Dalles 

Dam, Columbia River, Oregon and Washington, 2012

U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2013–1110
Cover: Photograph showing paired D-ring collection nets ready for deployment into the Columbia 

River in 2010. (Photograph by the Washington Department of Fish and Wildlife.) 
Capture of White Sturgeon Larvae Downstream of The 

Dalles Dam, Columbia River, Oregon and Washington, 2012 

By Michael J. Parsley and Eric Kofoot

Prepared in cooperation with the Chelan County Public Utility District

Open-File Report 2013-1110

U.S. Department of the Interior

U.S. Geological Survey 
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

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Suggested citation:

Parsley, M.J., and Kofoot, E., 2013, Capture of white sturgeon larvae downstream of The Dalles Dam, Columbia 

River, Oregon and Washington, 2012: U.S. Geological Survey Open-File Report 2013-1110, 12 p. 

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Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report.
iii

Contents

Abstract ......................................................................................................................................................................... 1

Introduction.................................................................................................................................................................... 1

Study Methods............................................................................................................................................................... 2

Site Selection and Capture of White Sturgeon in Early Life Stages............................................................................... 4

Conclusions and Recommendations ............................................................................................................................. 4

Acknowledgments ......................................................................................................................................................... 5

References Cited........................................................................................................................................................... 6

Figures

Figure 1. Image showing locations of netting sites A–E in the Columbia River downstream of The Dalles Dam......... 7

Figure 2. Photograph showing paired D-ring nets ready for deployment in the Columbia River near Northport, 

Washington in 2010....................................................................................................................................................... 8

Figure 3. Photograph taken in 2012 showing a single D-ring frame with self-support base and net with 24.6 liter 

collection bucket attached to the end............................................................................................................................. 9

Figure 4. Graph showing Columbia River flow and water temperature for June at The Dalles Dam, 2012.................. 9

Figure 5. Image of Columbia River study area showing white foam tracks as an indication of main river flow ........... 10

Figure 6. Image showing netting area with the wind-generated waves that are prevalent in this reach of the 

Columbia River............................................................................................................................................................ 11

Table

Table 1. Capture data for white sturgeon early life stages (free-swimming embryos and larvae) downstream of The 

Dalles Dam, Oregon and Washington, June 25–29, 2012........................................................................................... 12
iv

Conversion Factors and Datum

Conversion Factors

Multiply By To obtain

kilometer (km) 0.6214 mile (mi)

meter (m) 3.281 foot (ft)

centimeter (cm) 0.03937 inch (in)

cubic foot (ft3) 0.02832 cubic meter (m3)

liter (l) 0.2462 gallon

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Datum

Horizontal coordinate information is referenced to the World Geodetic System (WGS-84) 
1 

Capture of White Sturgeon Larvae Downstream of

The Dalles Dam, Columbia River, Oregon and 

Washington, 2012

By Michael J. Parsley and Eric Kofoot

Abstract 

Wild-spawned white sturgeon (Acipenser transmontanus) larvae captured and 

reared in aquaculture facilities and subsequently released, are increasingly being used in 

sturgeon restoration programs in the Columbia River Basin. A reconnaissance study was 

conducted to determine where to deploy nets to capture white sturgeon larvae

downstream of a known white sturgeon spawning area. As a result of the study, 103 

white sturgeon larvae and 5 newly hatched free-swimming embryos were captured at 3 of 

5 reconnaissance netting sites. The netting, conducted downstream of The Dalles Dam on 

the Columbia River during June 25–29, 2012, provided information for potentially 

implementing full-scale collection efforts of large numbers of larvae for rearing in 

aquaculture facilities and for subsequent release at a larger size in white sturgeon 

restoration programs. 

Introduction

The purpose of this study was to investigate the feasibility of capturing wildspawned white sturgeon larvae from the Columbia River downstream of The Dalles Dam 

in numbers sufficient to be removed to aquaculture facilities for subsequent rearing and 

release. The Washington Department of Fish and Wildlife has successfully netted white 

sturgeon larvae from the Columbia River near Northport, Washington, reared the larvae 

for several months in their Sherman Creek Hatchery, and subsequently released several 

thousand juvenile white sturgeon into Lake Roosevelt, an impoundment on the Columbia 

River (Washington Department of Fish and Wildlife, unpub. data, 2010, 2011). Sturgeon 

populations are declining in many areas of the Columbia River that are impounded by 

dams (Miller and others, 1995) and capture, rearing, and subsequent release of young 

wild-spawned white sturgeon is one alternative for restoring abundance in areas where 

natural production is low or non-existent. Capture of larvae presents an alternative to 

traditional approaches of wild broodstock capture, transportation, and spawning within an 

aquaculture facility. Capture of broodstock can be labor intensive or impractical because 

of low capture probability in areas where adult fish numbers are low. The transportation 

of mature fish, which typically exceed 1.5 m in length, to and from an aquaculture facility 
2 

for spawning and return to the river requires specialized trucks and procedures. In 

contrast, white sturgeon larvae typically can be captured each year downstream of most 

known spawning areas. Larvae can be transported to hatcheries in standard coolers, and a 

subsequent return trip to release broodstock is not necessary. 

Chelan County Public Utility District (PUD) requested that the U.S. Geological 

Survey (USGS) conduct a feasibility study to determine if capturing wild-spawned

sturgeon larvae can be a viable alternative to hatchery production for meeting their 

Federal Energy Regulatory Commission licensing conditions. This study was conducted 

in response to this request. We considered this to be a reconnaissance study because there 

was uncertainty regarding potential netting sites, how debris would affect net 

performance, and how many larvae would be captured per unit of time. This information 

will be used to estimate sampling efforts for future collection activities. The USGS has 

captured white sturgeon in early life stages from the Columbia River downstream of The 

Dalles Dam in previous studies (Parsley and others, 1993; U.S. Geological Survey, 

unpub. data, 1995, 1998), but it was not the goal of those studies to maximize catches of 

sturgeon during their larval dispersal phase. Thus, the objective of this pilot study was to 

identify potential sites suitable for long-term deployment of nets that did not interfere 

with commercial navigation or Tribal fishing activities, and determine how long the nets 

could be fished before the amount of debris became too great to effectively fish or 

resulted in mortality of white sturgeon in early life stages. The potential study reach 

extended from the Highway 197 Bridge (river km 308) downstream approximately 11 km 

(fig. 1).

The study was conducted by the USGS in cooperation with the Chelan County 

PUD. The work directly addressed several aspects of the USGS Science Strategy (U.S. 

Geological Survey, 2007). Understanding the conservation requirements and 

opportunities for restoration of fisheries in a large, managed inter-jurisdictional river is 

relevant to the “Understanding Ecosystems and Predicting Ecosystem Change” strategic 

direction. Working with the Chelan County PUD and others to restore fisheries is a 

critical step toward informed river management. This study also supported several of the 

goals and objectives of the Fisheries—Aquatic and Endangered Resources Program 

within the Ecosystems Mission Area. This work will assist with evaluations of the 

effectiveness of management plans to recover imperiled aquatic organisms, as it will 

assist with the development of restoration and reestablishment techniques for white 

sturgeon, and it provides timely, responsive, and cost-effective information in response to 

issue-driven, site-specific management problems involving targeted short-term research. 

Study Methods

Drift-fishing plankton nets deployed on the riverbed have long been used to 

collect early life stages of white sturgeon in the Columbia River and elsewhere (Parsley

and others, 1993; McCabe and Tracy, 1994). The Washington Department of Fish and 

Wildlife recently refined techniques for long-term (for example, overnight) netting by 

incorporating a large collection bucket, a self-standing base, and a mooring system that 

enables retrieval and redeployment of the net (figs. 2 and 3). A netting effort consisted of 

single or paired deployments of inverted U-shaped plankton nets, commonly referred to 
3 

as D-ring nets, which are weighted and fished on the riverbed. The nets are deployed on 

moorings to collect sturgeon in early life stages (eggs, free-swimming embryos, and 

larvae) downstream of spawning sites. The nets are fitted with a large collection bucket 

specifically designed to minimize harm to fish that are collected.

Specifically, the individual net frame openings measured 0.8-m wide by 0.6-m 

high. The frames were welded to a rectangular base constructed of 2.54-cm steel square 

tubing that allows the nets to stand upright on the river bottom. The nets, made of 1.6-

mm knotless nylon mesh (Delta weave), were 3.4 m in length and had a mouth diameter 

of 68.58 cm and a cod opening of 10.16 cm. A 24.6-L collection bucket was attached to 

the cod end of the net. The collection buckets were modified by cutting five columns of 

3.18-cm-diameter holes (4 holes per column) covered with 750-μm Nitex® mesh screen. 

A 10.16-cm-diameter hole was cut in the center of the bucket lid and two 10.1-cm closet 

flanges were placed back-to-back on either side and attached with bolts. A 15.24-cmdiameter ABS pipe glued into the outer flange was used for net attachment. Ground gear 

consisted of a Y-bridle fastened to the frame base with a line leading to a 45-kg fluke 

anchor. A vertical line with floats was tied to the top of the frame and extended to the 

water surface for deploying and retrieving the nets. Line lengths varied depending on 

depth. 

Net deployment sites were determined from prior knowledge of capture locations

of white sturgeon in early life stages (Parsley and others, 1993) and by examining 

physical river structure including substrates, bathymetry, and hydrodynamic model 

output for suitable depths and water velocities. Onsite evaluation and assessment of 

proximity to the federally maintained navigation channel, Native American traditional 

fishing locations, and prevailing wind and surface-wave conditions ultimately determined 

whether a site could be fished with nets. 

Once suitable sites were identified, the nets were deployed and left to fish for 8 or 

more hours. Geographic coordinates from a global positioning system receiver were

recorded at all netting sites along with the date and time of net deployment, and retrieval 

and water depth. Upon retrieval, the contents of the collection bucket were emptied into a 

sorting tray and captured white sturgeon were counted. 

The schedule for the field work was based primarily on ambient Columbia River 

water temperatures. Spawning by sturgeon in The Dalles Dam vicinity typically begins 

when water temperatures reach 12°C, and peaks when water temperatures reach 14–

15°C. Given that targeted fish would be approximately 12 days of age, which is the age at 

which downstream dispersal typically occurs, collection efforts were set to begin when 

water temperatures had been equal to or greater than 15°C for at least 6 days (fig. 4). 
4 

Site Selection and Capture of White Sturgeon in Early Life Stages

Columbia River flows were exceptionally high during June 25–29, 2012, when 

the netting efforts occurred (fig. 4). Netting efforts were conducted adjacent to the 

thalweg and navigation channel to avoid high water velocities that prevailed during the 

high flows. Water depths at netting sites ranged from 16.8 to 32.0 m. Sturgeon catches 

were highest in the three sites farthest downstream (sites C, D, and E) with a total of 103 

larvae and 4 free-swimming embryos (table 1). The highest overall sturgeon catch was 86 

larvae at site D. Netting at sites A and B resulted in the capture of only one sturgeon freeswimming embryo. Netting resulted in the immediate mortality of four larvae. All other 

larvae appeared to be in good condition and were observed swimming within the sorting 

trays, suggesting that they would have been suitable for transport to a rearing facility. The 

amount of debris that accumulated in the collection bucket varied within and among sites, 

with a median of 25 percent of the bucket by volume (range 0–100 percent). 

Conclusions and Recommendations

The work involved with this study demonstrated that there is potential to capture 

white sturgeon in early life stages that could be transported to rearing facilities for use in 

restoration or population supplementation elsewhere in the Columbia River. The 1-weeklong effort presented in this report was exploratory in nature and provided information on 

where future collection efforts should be focused. It is common in developing fisheries to 

see rapid increases in catch-per-unit effort as fishers gain knowledge of fishing grounds 

and experience in capturing target species or, in this case, a specific age class of a single 

species. The long duration of the spawning period and short incubation of white sturgeon 

eggs would ensure that early life stages of white sturgeon would be present for several 

weeks or months in each year, thus enabling the development of a netting program that 

could address concerns about inbreeding or outbreeding depression that arise in 

aquaculture-based fish restoration programs. 

The Columbia River downstream of The Dalles Dam was a challenging 

environment because the selection of suitable netting sites that could be fished for 

extended periods had to consider river channel morphometry, commercial navigation, 

Native American fishing locations, and recreational anglers. The availability of suitable 

locations was further constrained by factors influencing crew safety including appropriate 

current velocity and wind generated waves. Netting sites ultimately selected for this study 

came from careful consideration of each of these factors as well as information from 

previous studies in which white sturgeon larvae were captured. Previous catch data 

revealed that white sturgeon larvae can be captured from downstream locations where the 

river channel widens and water velocities are reduced. However, wind-generated waves 

can become problematic on some days in this area (fig. 5). Netting closer to the thalweg 

here and at sites farther upstream or downstream may be possible during lower water 

years with reduced river discharge during the larvae dispersal period. 
5 

Future netting efforts to provide greater numbers of white sturgeon larvae 

sufficient to transport to hatcheries for rearing should use a vessel with the following 

features:

• An open bow design of adequate length for work in high waves generated by 

prevailing high winds that are common in the Columbia River Gorge (fig. 6). 

In this study, wind-generated waves made work difficult or precluded lifting 

some of the nets on some days in the 7-m-long vessel used. A vessel with an 

open bow design would allow easy access to the anchor pulpit and windlass, 

thus improve crew efficiency. 

• Fairleads or vertical rollers on the anchor pulpit to keep the anchor line on the 

pulpit roller during net lifting or anchor retrieval. 

• The davit used for lifting nets mounted forward of amidships for improved 

safety. 

• An anchor windlass or capstan adequate to lift the 45-kg anchors and rode. 

Drag from the water current on the long anchor rode required at the deep sites 

required substantial power to lift and retrieve anchors. 

Acknowledgments

Jason McLellan and Matt Howell, formerly from the Washington Department of 

Fish and Wildlife, and currently with the Confederated Tribes of the Colville 

Reservation, developed modifications to traditional D-ring nets and deployment methods 

that were used in this study. We thank them for sharing their thoughts and designs. This 

study was funded by the Chelan County Public Utility District, for which Joshua 

Murauskas was the technical point of contact. Nets, moorings, and ground gear used in 

this study were provided by Chelan County PUD. Assistance with the field work was 

provided by Dave Beardsley, Dennis Litchfield, Nate Clark, Chris Vanwey, and Ed 

Gutzwiler of the Chelan County Public Utility District. Joe Warren of the U.S. 

Geological Survey provided assistance with figures, tables, and the formatting of this 

report. Sturgeon netting efforts were authorized under Washington State Scientific 

Collection Permit 12-190, and Oregon Department of Fish and Wildlife Scientific Taking 

Permit Number 17251. 
6 

References Cited

McCabe, G.T., Jr., and Tracy, C.A., 1994, Spawning and early life history of white 

sturgeon, Acipenser transmontanus, in the lower Columbia River: Fishery Bulletin, v. 

92, p. 760–772. 

Miller, A.I., Counihan, T.D., Parsley, M.J., and Beckman, L.G., 1995, Columbia River 

Basin white sturgeon, in LaRoe, E.T., ed., Our living resources—A report to the nation 

on the distribution, abundance, and health of U.S. plants, animals, and ecosystems: 

U.S. Department of the Interior, National Biological Service, Washington, D.C., p. 

154–158. 

Parsley, M.J., Beckman, L.G., and McCabe, G.T., Jr., 1993, Spawning and rearing habitat 

use by white sturgeons in the Columbia River downstream from McNary Dam: 

Transactions of the American Fisheries Society, v. 122, p. 217–227. 

U.S. Geological Survey, 2007, Facing tomorrow’s challenges—U.S. Geological Survey 

science in the decade 2007–2017: U.S. Geological Survey Circular 1309, 70 p. 
7 

Figure 1. Image showing locations of netting sites A–E in the Columbia River downstream of The 

Dalles Dam. River flow is from east to west. 

Highway 197 

The Dalles Dam

Netting sites
8 

Figure 2. Photograph showing paired D-ring nets ready for deployment in the Columbia River near 

Northport, Washington in 2010. Photograph courtesy of Washington Department of Fish and 

Wildlife. 
9 

Figure 3. Photograph taken in 2012 showing a single D-ring frame with self-support base and net 

with 24.6 liter collection bucket attached to the end. A surface float for net retrieval would be 

attached to the loop at the top of the net frame. 

Figure 4. Graph showing Columbia River flow and water temperature for June at The Dalles Dam, 

2012. Flows in 2012 were much higher than the 10-year averages, and water temperatures were 

colder in 2012 than the 10-year averages. 
10

Figure 5. Image of Columbia River study area showing white foam tracks as an indication of main 

river flow. 

Netting sites

Netting sites

Netting sites
11

Figure 6. Image showing netting area with the wind-generated waves that are prevalent in this 

reach of the Columbia River. River flow is from south to north. Wind direction is northwest to 

southeast.

Netting sites

Netting sites

Netting sites
12

Table 1. Capture data for white sturgeon early life stages (free-swimming embryos and larvae) downstream of The Dalles Dam, Oregon and 

Washington, June 25–29, 2012. 

[Set numbers refer to consecutive efforts at each site. Site D was fished with a paired net; all other sites were fished with a single net. Debris was then estimated 

as the fractional volume in the collection bucket] 

Site Latitude Longitude Depth

(m) Set Duration(hr)

Volume 

of debris

(percent) 

Number of

sturgeon freeswimming

embryos 

Number of 

sturgeon 

larvae 

Number of 

dead

sturgeon

larvae 

Catch

per

hour

A 45 38 29.3N 121 12 02.8W 32 1 22.08 6.25 0 0 0 0.00

2 25.18 25 0 0 0 0.00

3 26.25 0 1 0 0 0.04

B 45 38 32.4N 121 12 00.6W 29.6 1 17.52 6.25 0 0 0 0.00

2 24.58 33 0 0 0 0.00

3 25.25 0 0 0 0 0.00

C 45 39 19.0N 121 12 28.8W 16.8 1 14.33 20 0 0 0 0.00

2 24.42 33 0 2 1 0.08

3 8.83 33 0 0 0 0.00

4 11.42 12.5 4 1 0 0.44

D 45 39 20.8N 121 12 26.3W 21.3 1 23.47 5 0 0 0 0.00

2 24.08 100 0 2 0 0.08

3 9.83 50 0 32 0 3.26

4 13.67 25 0 52 3 3.80

E 45 39 23.9N 121 12 26.7W 19.8 1 21.25 50 0 0 0 0.00

2 11.42 33 0 10 0 0.33

3 12.12 12.5 0 4 0 0.00
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Publishing Network, Tacoma Publishing Service Center

For more information concerning the research in this report, contact the 

Director, Western Fisheries Research Center

U.S. Geological Survey

6505 NE 65th Street

Seattle, WA 98115

http://wfrc.usgs.gov/
Parsley and Kofoot—Capture of White Sturgeon Larvae Downstream of The Dalles Dam, Columbia River, Oregon and Washington, 2012—Open-File Report 2013–1110