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26 January 2010

To: Jody Brostrom

From: Brian J. McIlraith and Christopher C. Caudill

Re: Evaluation of factors affecting migration success and spawning distributions of adult Pacific lamprey in the Snake River, Washington and Idaho; a progress report.

INTRODUCTION

Pacific lampreys (Lampetra tridentata) are an anadromous, parasitic fish of the lamprey

family, petromyzontidae. Their natural range extends along the Pacific Coast from Baja California,

Mexico, throughout the Bering Sea (Orlov et al. 2008), and to Hokkaido Japan (Simpson and Wallace

1982) and they are native to the Columbia River basin (Close et al. 2002). Pacific lamprey are among

the oldest existing vertebrates, changing little in the past 400 million years (Bond 1996; Gess et al.

2006). Although considered a primitive fish (Renaud 1997), they have evolved a complex life history

that spans multiple habitats, geographic ranges, and spatial scales.

This diverse life history has made Pacific lamprey vulnerable to a host of anthropogenic

disturbances including flow regulation (Close et al. 2002), hydroelectric impacts (Keefer et al.

2009b), and degradation of spawning and rearing habitats. Despite being the largest and most

abundant lamprey species in the Columbia River Basin (Wydoski and Whitney 2003), Pacific

lamprey populations have declined dramatically in recent decades (Close et al. 2002) as evidenced by

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decreasing annual daytime counts of returning adults at Columbia and Snake River hydroelectric

facilities. Adult daytime counts at Lower Granite Dam, the last facility equipped with fish passage

facilities on the Snake River, have been reduced to double digits with a low of 12 fish counted in

2009 (archived at: http://www.cbr.washington.edu/dart).

These declines have focused attention on Pacific lamprey populations within the Columbia

River Basin. The Pacific lamprey is important ecologically and culturally (Close et al. 2002). They

are an important prey species for a variety of predators (Merrell 1959; Poe et al. 1991; Roffe and

Mate 1984) due to their high nutritional value (Whyte et al. 1993) and relative ease of capture (Close

et al. 2002). The benthic (Vladykov 1973) and anadromous portions of their life cycle are likely

important components to nutrient cycling (Close et al. 2002). Pacific lampreys are also culturally

important to the Native American tribes of the Columbia River Basin as they have been used for

commercial, medicinal, and ceremonial purposes for thousands of years (Close et al. 2002).

Overall efforts to conserve, manage, and rehabilitate Pacific lamprey populations have been

minimal compared to resources devoted to salmon recovery in the Pacific Northwest (Close et al.

2002; Renaud 1997). Management has been hindered by negative perception within western culture

of the species as an invasive, its relatively low commercial value, and a lack of basic biological

information. Nonetheless, decreasing population estimates have led to increased protection efforts

and the state of Oregon designated lamprey as a species at risk in 1993 and a protected species in

1996. In 2003, a petition to list Pacific lamprey as an endangered species under the Endangered

Species Act (ESA) by the U.S. Fish and Wildlife Service (USFWS) was denied primarily due to an

overall lack of basic biological, population, and stock structure information (Keefer et al. 2009b).

Much of what is known about petromyzonid biology stems from sea lamprey (Petromyzon

marinus) research in the Great Lakes and lamprey research in Canada. Whether observations for sea

lamprey are directly applicable to Pacific lamprey or not is unknown. Research dealing with

Columbia River lamprey populations has increased in recent years, though it has been primarily

focused on improving passage at Columbia River hydroelectric facilities (Moser et al. 2002). Very

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few studies have focused on the general seasonality, route selection, or rates of adult migrations

(Moser et al. 2002). Within Idaho projects have focused on larval rearing (Hammond 1979), and

habitat and recruitment of Pacific lamprey (Claire et al. 2007). Little information on adult Pacific

lamprey migration through the impounded lower Snake River or in unimpounded reaches of the

Snake Basin is available.

In this three-year study, we radio tagged adult Pacific lamprey and monitored their

movements through the lower Snake River drainage above Lower Granite Dam. This study area

included reaches unimpounded by hydroelectric facilities, though many reaches had flow regimes

controlled by upstream dams (e.g, Dworshak Dam, Hells Canyon Dam). Our objectives were to

determine the migration timing, behavior, migration rates, and overwintering habitat of tagged adults

and determine which environmental factors were correlated with these movement patterns.

Specifically we wanted to determine how migrating lamprey responded to the river environments of

the Snake and Clearwater Rivers before, during, and after overwinter holding, and to determine the

final distribution of the tagged population. Information contained in this paper should add to the

limited biological information for Idaho lamprey populations as well as to improve the protection,

management, and rehabilitation of the Pacific lamprey within the lower Snake River and the state of

Idaho.

METHODS

Study area

The Snake River drains 280,000 km2 of Idaho as well as portions of Washington, Oregon, and

Wyoming. The upper and lower portions of the Snake River are separated by Hells Canyon Dam

(Figure 1, HC, river kilometer [rkm] 397, measuring from the mouth of the Snake River) which is

impassable to upstream migrating fish. Upstream migrations of adult Pacific lamprey were monitored

in portions of the Snake River above Lower Granite Dam, WA (LGR, rkm 173), the last passable dam

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on the Snake River system, and below Hells Canyon Dam. This area includes the two major

tributaries of the lower Snake River; the Clearwater and Salmon Rivers. The Clearwater River (rkm

224) drains approximately 25,000 km2 and is the largest tributary of the Snake River. It joins the

Snake River near the town of Lewiston, ID and its major tributaries include the South Fork

Clearwater (rkm 344), Selway (rkm 381), and Lochsa Rivers (rkm 381). The North Fork Clearwater

River is also a major tributary of the Clearwater, though passage is blocked near the confluence of the

mainstem Clearwater by Dworshak Dam. Deep-water releases from Dworshak Reservoir aimed at

aiding salmon migration strongly alter the thermal regime of the Clearwater and lower Snake rivers

downstream of Dworshak Dam during summer months. The second largest tributary of the Snake

River is the Salmon River (rkm 303) and it drains approximately 36,000 km2. Its major tributaries

include the Middle Fork Salmon (rkm 622), Lemhi (rkm 719), and Pashimeroi Rivers (rkm 792).

The lower Snake River is highly regulated and has four hydroelectric facilities equipped with

fish passage facilities (Figure 1). These four dams are Ice Harbor (IHR, rkm 16), Lower Monumental

(LMO, rkm 67), Little Goose (LGO, rkm 113), and Lower Granite (LGR). Adult lamprey destined

for Idaho must ascend these facilities prior to entering relatively free-flowing portions of the Snake,

Salmon, and Clearwater Rivers. Adult pacific lampreys enter the Snake River in late spring, migrate

upstream until late fall, and overwinter before resuming upstream migration in the early spring.

Spawning in Idaho typically occurs in the late spring and early summer in the year following

freshwater entry.

Lamprey collection, tagging, and tracking

Pacific lampreys used in this study were collected at Lower Monumental and Little Goose

Dams. All fish were collected from salmonid juvenile bypass systems from July to October from

2006 to 2008. Once collected, lampreys were held in 190 L containers that were provided with a

consistent flow of aerated river water. Lampreys were held until tagging and release, which occurred

within 48 hours of collection.

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Before tagging, fish were anesthetized with 60 ppm clove oil, measured (length and girth to

the nearest mm), and weighed (nearest g). Weight data were not collected in 2006. No fish with girth

< 9 mm at the dorsal fin were radio-tagged (< 3% rejected based on size). Lampreys were surgically

implanted with uniquely coded radio tags (18.3 mm length, 8.3 mm diameter, 2.1 g in water; model

NTC-4-2L, Lotek Wireless, Inc) with methods approved by the University of Idaho Animal Care and

Use Committee and outlined in Moser et al. (2002). Radio transmitters represented a mean weight

increase of < 1.0% (range 0.29 to 0.78 %) to tagged individuals in all years. Sex was determined by

examination of the gonads. Individuals that were unable to be sexed by these methods were

categorized as sex unknown (U).

After tagging, lampreys were placed in a 142 L cooler filled with oxygenated river water.

Water temperature was maintained at 15-20 C° with the use of 4 L containers of frozen river water.

Fish were transported from their tagging locations and released upstream from Lower Granite Dam at

Offield landing (OFF, rkm 174), Wawawai campground (WAI, rkm 178), and Red Wolf crossing

(RWC, rkm 226).

Lamprey movements were recorded using a combination of two methods. An extensive

network of fixed-site radio telemetry receivers jointly maintained by the University of Idaho and the

U.S. Fish and Wildlife Service (USFWS) was used to continuously monitor timing of lamprey

movements (Figure 1). Fixed-site receivers (Lotek Engineering, Inc., Ontario, Canada) were placed

at the mouths of most major tributaries within the Snake, Salmon, and Clearwater River drainages

(Figure 1). Each receiver was equipped with one or more 4-element Yagi antenna and a power

source. Antennas faced downriver at a 45° angle offshore towards the thalweg. Fixed-site receivers

were downloaded periodically and compiled into a larger telemetry database for future analysis.

These files provided information on date and time of day when a unique tag was within the detection

range of a receiver.

Terrestrial mobile tracking (boat and automobile) was used to determine locations of tags

between fixed site receivers. The roaded sections of the Snake, Salmon, and Clearwater Rivers were

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surveyed periodically via automobile. During the fall (Aug-Nov) these sections were surveyed every

two weeks until it was determined that fish were holding fixed positions. Surveys continued monthly

throughout the winter (Dec-Feb) until indications of movement were observed. In the spring (Mar-

June), surveys continued every two weeks until no actively transmitting tags were found (the rated

life of the tags was 251 days). Mobile tracking by boat was conducted on unroaded portions of the

Snake River upriver from Lewiston, ID (rkm 224) in October of 2007 and February of 2009.

Once tag locations were determined, a Yagi handheld antenna was used to further pinpoint

lamprey location. Latitudes and longitudes of these locations were recorded using a handheld GPS

unit (Garmin GPS 76) and corresponding river kilometer positions were recorded to facilitate data

analysis. Any fish that was detected upstream of the Snake and Clearwater confluence was deemed a

“successful” migrant as potential spawning habitat exists above this location.

Analysis of telemetry data

All radiotelemetry data were entered into a larger database and processed as described in

Moser et al. (2002). The radiotelemetry database consisted of tagging (size metrics, tagging date,

release date, release location, etc.), transmitter (code, frequency, date, time, location, and power of

transmission at fixed sites), and mobile tracking records (latitude, longitude, rkm, location

description). Transmitter records were filtered for invalid records which included duplicate records,

records that occurred prior to release, and single records without first and last detections. All invalid

records were removed from analysis but were kept in a separate table for future reference.

Migration rates (km·day-1) and passage times (days) through reaches were calculated from a

combination of release, fixed-site, and telemetry records. Reaches were defined as the area between

release location (REL) and upstream fixed-site receiver (FS), downstream and upstream receivers

(FS-FS), or mobile tracked location and an upstream receiver (MBT-FS). Release and fixed-site data

were used to calculate migration rates and passage times for fall and spring. Spring movements were

difficult to calculate due to variability in starting locations within long reaches, overwinter holding

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behavior, and limited FS-FS detections in spring. Migration rates and passage times were calculated

using the first record (F1 detection) at the upstream location and the last record at the downstream

location. Rates and passage times were expressed as medians due to non-normal distributions.

Analysis of environmental and lamprey count data

Daily, monthly, and annual mean water temperature and discharge data for the Snake River at

Lower Granite Dam and daytime counts of adult Pacific lamprey passing fishways at Lower

Monumental and Little Goose dams (archived at: http://www.cbr.washington.edu/dart) were

provided by the U.S. Army Corps of Engineers (USACE). Similar water temperature and discharge

data for the Snake and Clearwater Rivers were provided by U.S. Geological Survey (USGS) gauging

stations near Anatone, WA (rkm 269), Spalding, ID (rkm 245), and Orofino, ID (rkm 298).

RESULTS

Collection, tagging, and tracking

A total of 146 adult lampreys were collected and surgically implanted with radio transmitters

from 2006-2008: 50 in 2006, 46 in 2007, and 50 in 2008 (Table 1). A majority of lampreys were

collected at Little Goose Dam: 68% of the sample in 2006, 78% in 2007, and 86% in 2008. In 2007

and 2008 collection and tagging efforts were in approximate proportion to daytime adult counts at

LMO and LGO whereas in 2006 median tag dates were slightly later (Figure 3). Median tag dates at

LGO and LMO were later than median dam passage dates based on visual counts except at LGO in

2007 (Table 2). Logistical constraints in 2006 prevented collection and tagging until late July.

Overall run timing was later in 2008 than 2006-2007, contributing to differences among years in

median tag dates.

In 2006, 19 male, 29 female, and 2 unknown lampreys were radio tagged with mean (±

standard deviation) length 67.8 ± 3.7 and mean girth 10.8 ± 0.7 (Table 1). Tagging dates ranged from

25 July to 19 September. In 2007, 17 male, 20 female, and 9 unknown were radio tagged with mean

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length 65.1 ± 4.0, mean girth 10.9 ± 0.7, and mean weight 454.7 ± 82.9. Tagging dates ranged from

22 July to 16 October (Table 1). In 2008, 23 male, 20 female, and 7 unknown were radio tagged with

mean length 66.3 ± 3.3, mean girth 11.0 ± 0.6, and mean weight 447.16 ± 62.2. Tagging dates ranged

from 4 August to 4 September (Table 1).

Radio-tagged lamprey represented a significant percentage of the adults counted at adult

passage facilities (Figure 3), though previous studies suggest that daytime counts may underestimate

overall dam passage due to nocturnal movement by lamprey (Clabough et al. 2009; Keefer et al.

2009a; Moser et al. 2002). Regardless, because all adults were collected from juvenile bypass

facilities, this result also suggests a large proportion of adult lampreys passing Snake River dams

fallback downstream through the JBS facilities, especially at Little Goose Dam.

Within year size metrics were all positively correlated (length × girth r = 0.67-0.80; length ×

weight r = 0.80-0.84; girth × weight r = 0.90-0.90; all P < 0.001). Size metrics were all weakly

correlated with release date (mean r = -0.12, range = -0.02-0.34) with one significant pairwise

comparison (length × releasedate, P = 0.0138). Most comparisons between size metrics and

collection location were insignificant, with the exception that lamprey collected at LMO were heavier

than those collected at LGO in 2008 (P < 0.02). Length was significantly different between females

and males as well as between females and unknowns in 2007 (P < 0.02). Weight was also

significantly different between these groups (M/F and F/U) in 2008. There were no significant

differences in lamprey size among release locations.

In 2006, releases were split between Offield landing and Red Wolf crossing (Table 1).

Overall, 64% of radio-tagged fish had valid telemetry records in 2006. In 2007, two fish were

released separately above Lower Granite Dam at Offield landing and Wawawai campground. Only

the lamprey tag released at WAI was detected upstream (50%). The remaining 44 fish were released

alternately between the north and south shores at RWC (Figure 1) and 80% of these radio-tagged fish

had valid telemetry records. In 2008, all fish were released at RWC and 98% had valid telemetry

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records. The difference in the proportion detected among years was probably related to differences in

the distance to a receiver between the release sites.

Migration timing and river environment

Continuous monitoring of fixed site receivers indicated that lampreys were most active

between sunset and sunrise with peak movements occurring between 1900 and 0500 in all study years

(Figure 4), although some fish passed receivers during daylight hours. Nocturnal lamprey movement

was well characterized by two individual lampreys that were logged continuously on fixed-site

receivers as they moved upstream at night, ceased upstream migration at sunrise within the detection

range of a receiver, and resumed upstream migration at sunset (black lines, Figure 5). Most upstream

movement ended by mid October.

We used the first detection of adult lamprey at the first fixed-site receivers upstream of the

SNR-CWR confluence to evaluate seasonal patterns of movement into the two drainages. Upstream

migration occurred primarily during the fall (Figure 6). Differences between fall and spring fixed-site

detections were significant within all three years (χ2 = 3.86-24.20, P < 0.05). Adult lamprey moved

into the Snake and Clearwater rivers with equal frequency in the fall (χ2 = 0.06-3.10, P > 0.05),

however more fish were detected entering the Clearwater in the spring than the Snake in all three

years (Figure 6). In 2006 and 2008 there were no significant differences in overall drainage choice

(χ2 = 1.13-3.45, P > 0.05) but there was a significant difference in 2007 (χ2 = 6.09, P < 0.05). In 2007

and 2008 there were mobile tracked tags detected in the Snake and Clearwater drainages that did not

have corresponding fall or spring fixed-site detections (Figure 6, S-MBT). Movement timing (fall or

spring tributary entry) for these tags is unknown.

Median detection dates at the Snake receiver (SNR) were 50 and 25 days earlier than at the

Clearwater receiver (CWR) in 2006 and 2007 (Figure 7). Within the Clearwater drainage, median

detection dates at the TOS receiver (Nez Perce Tribal Fisheries office, see A-1) were 4, 12, and 16

days later than at the CWR receiver from 2006 to 2008. Fish entered the Snake River progressively

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later from 2006 to 2008 while this pattern was reversed in the Clearwater River (Figure 7). Detection

dates were most variable in 2006 for the Snake (CV = 26.0) and Clearwater Rivers (CV = 41.0). This

variability is likely due to a delayed tagging schedule and more releases near Lower Granite Dam in

2006 (N = 24). As a result, direct comparisons between 2007 and 2008 are more appropriate. In

2008 median detection dates were the same for both receivers (Table 4).

Fall movement patterns in the Snake and Clearwater Rivers were uncorrelated or only weakly

correlated with decreasing discharge and water temperature (Figures 8 & 9). Discharge in the Snake

decreased rapidly from July to August (Figure 8). In contrast, discharge in the lower Clearwater

River remained above base flow in summer (Figure 9), caused by cool-water augmentation releases

from Dworshak reservoir (Connor et al. 1998). Most lamprey movement occurred with little

correlation to changes in Snake and Clearwater discharge, though there were fixed-site detections in

the Clearwater River in November of 2006 and one in 2008 associated with spikes in discharge

(Figure 9). In all three years median SNR and CWR detection dates occurred prior to the fall

decrease in water temperatures in early September (Figure 8) and October (Figure 9) for the Snake

and Clearwater Rivers, respectively.

Declining daylight hours (photoperiod) was somewhat more correlated with fall movement

patterns at SNR and CWR receivers than temperature or discharge (Figures 8 & 9). Active upstream

movement at fixed-site receivers in spring increased as the number of daylight hours began to

decrease. With the exception of 2006, reach entry dates in the Snake and Clearwater were relatively

consistent between years despite varying river conditions (Figures 8 & 9). Reach entry dates were

least variable at the SNR receiver where median dates differed by an average of 7 days.

River environments in the fall differed dramatically between the Snake and Clearwater Rivers

due to cool-water releases from Dworshak reservoir. Radio-tagged lampreys that entered the Snake

from July to October, experienced water temperatures that were on average 10°C warmer than did

adult lampreys entering the Clearwater during the same time period, suggesting little active selection

for one tributary over the other based on temperature preference during this period. Fish that

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migrated up the mainstem Clearwater past the confluence of the North Fork Clearwater and the

thermal effects of Dworshak then experienced temperatures similar to that in Snake during this same

period (Figure 10).

Migration rates and passage times

A total of 111 migration rates and passage times were calculated for 66 unique radio-tagged

Pacific lampreys during fall movement: 22 in 2006, 19 in 2007, and 70 in 2008 (Table 3). Migration

rates and passage times were calculated for 15 reaches, though low sample sizes prevented direct

comparisons for all but three reaches (RWC-SNR, RWC-CWR, and CWR-TOS). Eight different

fixed-site receivers had valid upstream detections (Table 4).

Migration rates and passage times varied between year, reach, and season. Annual median

migration rates during fall movement ranged from 1.9 km day-1 in 2006 to 10.6 km day-1 in 2008.

Variability among years was highest in 2006 (CV = 162.0) and lowest in 2008 (CV = 83.0). Most

fish migrated upstream at rates between 0.2 and 20.0 km·day-1 with some observed rates > 25.0

km·day-1 in all three years (Table 3). The lowest migration rates and longest passage times were

recorded between release and a fixed site observation (REL-FS) reaches (Table 3). Median rates in

REL-FS reaches were lower in each year (1.4-5.8 km·day-1) than FS-FS (fixed-site to fixed-site)

reaches (9.6-13.1 km·day-1). The RWC-CWR reach had the lowest median migration rates in all three

years (0.3-2.2 km·day-1) while the RWC-SNR reach had the highest median migration rates in all

three years (13.5-35.7 km·day-1). In addition, the RWC-SNR reach had the highest individual rates in

each year: 38.1 in 2006, 41.1 in 2007, and 38.7 in 2008.

Migration rates were slower in spring, based on fewer observations. A total of 31 migration

rates and passage times were calculated for 27 unique radio-tagged Pacific lampreys during spring

movement: 11 in 2006, 13 in 2007, and 7 in 2008. Spring migration rates were estimated from FS-

FS, REL-FS, and MBT-FS reaches. Medians for combined REL-FS and MBT-FS rates were 0.3

km·day-1 (2006), 0.3 km·day-1 (2007), and 0.1 km·day-1 (2008). FS-FS rates were calculated in 2006

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(N = 2) and 2007 (N= 2) for the CWR-TOS (2.6, 2.8, and 3.4 km·day-1) and TOS-SFC (1.2 km·day-1)

reaches.

Migration success and final distribution

From 2006 to 2008, 32 (64%), 37 (80%), and 49 (98%) of radio-tagged fish had valid

upstream detections after release (Table 5; Appendix B). A majority of tags were detected in the

Clearwater drainage in each year; 60% in 2006, 70% in 2007, and 63% in 2008 (Figure 12). Within

the Clearwater River drainage, multiple fish migrated into upper portions of the Selway, South Fork

Clearwater, and Lochsa Rivers (Table 5). Lamprey migrating up the Snake River past the Snake-

Clearwater confluence had final records in both the Snake (28%, 16%, and 20%) and the Salmon

rivers (13%, 14%, and 16%) in 2006, 2007, and 2008 (Table 5). In all years, multiple fish were

detected in the upper Salmon, near the mouth of the Middle Fork Salmon (Figure 12). Tags were also

detected in the Imnaha drainage in 2006 (N =1) and 2008 (N = 1).

DISCUSSION

Adult Pacific lamprey tagged in this study completed most of their observed movement in the

fall, overwintered primarily in free-flowing habitat, traveled mostly at night, and ultimately

distributed themselves throughout much of the Clearwater, Snake, and Salmon River drainages. A

majority of radio-tagged lamprey successfully migrated above the Snake-Clearwater confluence into

potential spawning areas. Overall migration patterns corresponded weakly with water temperature

and discharge while fall migration was associated with decreasing daylight.

Adult lampreys were primarily collected from juvenile bypass systems at Little Goose dam,

where the number collected for tagging was a substantial proportion of the dam count. This study

indicates that ~40% of the annual daytime count at Lower Goose dam entered the juvenile bypass

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system and “fell back” (Table 2). This fallback estimate represents a minimum estimate because it

includes only adults collected for tagging from the juvenile bypass system. Daytime adult counts at

Snake River hydroelectric facilities generally decrease at upstream dams and as a result more fish

would be expected at downstream juvenile bypass facilities such as Lower Monumental dam if all

other factors were equal. Reasons for greater observed fallback at Little Goose than Lower

Monumental Dam may have included differences in juvenile sampling, differences in fishway exit

and juvenile bypass structure and orientation, and differences in operation affecting migration cues in

the forebay. Specifically, the location of adult fish ladders in relation to juvenile bypass intakes may

have an effect on numbers of fallback fish. Although daytime counts may underestimate overall adult

passage (Clabough et al. 2009; Keefer et al. 2009b; Moser et al. 2002) the estimated fallback may

overestimate the true proportion of the run falling back, these results suggest fallback may be

significant factor affecting migration success of adult lamprey past lower Snake River dams.

Overall detection efficiency increased in each year of this study (Table 5). In 2006, releases

were split between reservoir (LGF) and free-flowing (RWC) locations and LGF released adults had a

lower upstream detection rate (46%). RWC fish in 2006 had a detection rate of 81% which is

comparable to RWC fish in 2007 (82%) and 2008 (98%). Fish were released primarily at RWC in

2007 and 2008 to increase sample size of fish migrating past the Snake and Clearwater confluence

and into potential spawning habitat. Although 2006 data are limited, the low rate of upstream

detection suggests the potential considerable loss of adult lamprey in the Lower Granite Reservoir

and/or undetected fallback at Lower Granite Dam.

Adult Pacific lamprey exhibited primarily nocturnal movement at fixed-site receivers. This

pattern of nocturnal movement for Pacific lamprey has been well documented at hydroelectric

facilities (Moser et al. 2002) as well as through free flowing rivers (Robinson and Bayer 2005) within

the Columbia River basin. Multiple daytime detections were recorded as well, but percentages of

these were < 10% within study years with a higher overall percentage occurring in the spring.

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A majority of upstream migration occurred during the fall, which may indicate that migration

prior to overwinter holding is an important factor in determining potential spawning location.

Reasons for limited and apparently slower spring movement may include more favorable migration

conditions in the fall, physiological changes associated with sexual maturation, the distribution of

suitable spawning habitat, and/or mortality.

Rates of movement through release reaches were lower and more variable than fixed-site

reaches (Table 4). FS-FS reaches probably provide the most accurate representations of migration

rate because fish are actively migrating between known distances. Migration rates estimated for

REL-FS are potentially biased by a post-release recovery/holding period which may lead to a delay in

active upstream migration. This period seemed to be most evident in the RWC-CWR reach as

median migration rates were below 0.2 km·day-1 in all three years and overall passage times were

more variable than the REL-SNR reach (Figure 11). In contrast, the RWC-SNR had the highest

median rates and least variable passage times among years, suggesting that fewer adults released at

this location held position prior to upstream migration.

Once fish passed the Snake/Clearwater confluence, migration rates (range 1.7-34.1 km·day-1)

were comparable to migration rates found in other studies. Robinson and Bayer (2001) found that

rates ranged from 1.0 to 20.9 km·day-1 in free-flowing portions of the John Day River, OR while

Moser and Close (2003) reported rates from 13.9 to 20.9 km·day-1 in reservoir environments.

Variation in migration rates seems to reflect migration of radio-tagged lamprey through both reservoir

and free flowing environments.

Migrating adult Pacific lampreys are presented with two very different temperature regimes

from August to October below the Snake (20-23°C) and Clearwater (10-15°C) confluence due to

Dworshak cold-water releases (Figure 10), offering an observational experiment in temperature

selection. Despite the temperature difference, radio-tagged lamprey distributed themselves

approximately equally between the two drainages during late summer and early fall (Aug-Oct)

suggesting a lack of selection based on temperature or that other factors overrode any preference for

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temperature. Potential underlying mechanisms include a very broad range of temperature preference

or no temperature preference, population substructure and homing, or route selection based on other

unmeasured environmental factors (e.g., differences in concentrations of pheromones released by

larvae in the two different tributaries).

Seasonal changes in river discharge were not strongly associated with fall migration timing or

drainage choice. At shorter temporal scales, sudden increases in discharge (∆ 600 m3·sec-1) may

stimulate lamprey movement regardless of temperature, as evidenced by November fixed-site

detections in the Clearwater River. Surprisingly, water temperature did not seem to correspond with

overall fall migration patterns with the exception that movements at fixed-site receivers were limited

once water temperatures fell below 7-10°C (Figures 8 &9) , which has also been shown to be the

lower threshold for activity in sea lamprey (Applegate 1950; Binder and McDonald 2008).

Radio-tagged lamprey distributed themselves throughout the Snake, Salmon, and Clearwater

River drainages in a pattern that was consistent among years. Notably, approximately two radio-

tagged lampreys entered the Clearwater for each entering the Snake despite a Snake/Clearwater

discharge ratio of 2:1 (Figure 2). Under random dispersal, we expected that the entry ratios would be

proportional to the ratio of discharge between tributaries. The deviation from the expected ratio by

approximately a factor of four suggests that other processes affected drainage choice, including the

potential for active behavioral selection. Whether the selection is related to natal rearing experience

(homing) or other factors remains unknown, but it is plausible that higher concentrations of larval

pheromones in the Clearwater River may have played a role. Regardless, once adults reached the free

flowing portions of the lower Snake above the dams, radio-tagged lampreys were able to migrate

successfully into spawning habitat, indicating that improved reservoir passage may increase potential

spawning populations within the lower Snake drainage.

Further work related to this study will include analyzing the potential relationships between

downstream river environments, fish size metrics, telemetry efforts, and tagging environment with the

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observed fall cohort split. We also intend to use telemetry, river environment, and migration rate and

passage time data to estimate the relationship between migration rate and temperature and to estimate

the optimal temperature range for migrating Pacific lamprey. In addition to this study, telemetry data

collected from adult lamprey released into Clearwater River tributaries will be analyzed to determine

migration patterns of spawning adults in small order streams. This project was in collaboration with

Nez Perce Tribal Fisheries and results will be presented in a report forthcoming. The combination of

these two studies will hopefully improve our understanding of migration patterns of Pacific lamprey

at two different spatial scales.

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LITERATURE CITED

Applegate, V. C. 1950. Natural history of the sea lamprey, Petromyzon marinus, in Michigan. University of Michigan.

Binder, T. R., and D. G. McDonald. 2008. The role of temperature in controlling diel activity in

upstream migrant sea lampreys (Petromyzon marinus). Canadian Journal of Fisheries and Aquatic Sciences 65(6):1113-1121.

Bond, C. E. 1996. Biology of fishes, 2nd edition. Saunders College Publishing, Ft. Worth, Texas. Clabough, T. S., M. L. Keefer, C. C. Caudill, E. J. Johnson, and C. A. Peery. 2009. Use of night video

to quantify adult lamprey passage at Bonneville and The Dalles dams in 2007-2008. Technical Report 2009-9 of Idaho Cooperative Fish and Wildlife Research Unit to US Army Corps of Engineers, Portland District

Claire, C. W., T. G. Cochnauer, and G. W. LaBar. 2007. Pacific Lamprey Ammocoete Habitat

Utilization in Red River, Idaho. Pages 151-161 in. American Fisheries Society. Close, D. A., M. S. Fitzpatrick, and H. W. Li. 2002. The ecological and cultural importance of a

species at risk of extinction, Pacific lamprey. Fisheries 27(7):19-25. Connor, W. P., H. L. Burge, and D. H. Bennett. 1998. Detection of PIT-tagged subyearling chinook

salmon at a Snake River dam: implications for summer flow augmentation. North American Journal of Fisheries Management 18(3):530-536.

Gess, R. W., M. I. Coates, and B. S. Rubidge. 2006. A lamprey from the Devonian of South Africa.

Nature 443:921-924. Hammond, R. J. 1979. Larval biology of the Pacific lamprey, Entosphenus tridentatus (Gairdner), of

the Potlatch River, Idaho. University of Idaho., Moscow. Keefer, M. L., C. T. Boggs, C. A. Peery, and M. L. Moser. 2009a. Adult Pacific lamprey migration in

the lower Columbia River: 2007 radiotelemetry and half-duplex PIT tag studies. Technical Report 2009-1 of Idaho Cooperative Fish and Wildlife Research Unit to US Army Corps of Engineers, Portland District.

Keefer, M. L., M. L. Moser, C. T. Boggs, W. R. Daigle, and C. A. Peery. 2009b. Variability in

migration timing of adult Pacific lamprey (Lampetra tridentata) in the Columbia River, USA. Environmental Biology of Fishes 85(3):253-264.

Merrell, T. R. 1959. Gull food habits on the Columbia River. Research Briefs, Fish Commission of

Oregon 7(1):82. Moser, M. L., A. L. Matter, L. C. Stuehrenberg, and T. C. Bjornn. 2002. Use of an extensive radio

receiver network to document Pacific lamprey (Lampetra tridentata) entrance efficiency at fishways in the Lower Columbia River, USA. Hydrobiologia 483(1):45-53.

18

Orlov, A. M., V. F. Savinyh, and D. V. Pelenev. 2008. Features of the spatial distribution and size structure of the Pacific lamprey Lampetra tridentata in the North Pacific. Russian Journal of Marine Biology 34(5):276-287.

Poe, T. P., H. C. Hansel, S. Vigg, D. E. Palmer, and L. A. Prendergast. 1991. Feeding of predaceous

fishes on out-migrating juvenile salmonids in John Day Reservoir, Columbia River. Transactions of the American Fisheries Society 120(4):405-420.

Renaud, C. B. 1997. Conservation status of northern hemisphere lampreys (Petromyzontidae). Journal

of Applied Ichthyology 13(3):143-148. Robinson, T. C., and J. M. Bayer. 2005. Upstream migration of Pacific lampreys in the John Day

River, Oregon: behavior, timing, and habitat use. Northwest science 79(2-3):106-119. Roffe, T. J., and B. R. Mate. 1984. Abundances and feeding habits of pinnipeds in the Rogue River,

Oregon. The Journal of Wildlife Management:1262-1274. Simpson, J. C., and R. L. Wallace. 1982. Fishes of Idaho. Idaho Research Foundation. Vladykov, V. D. 1973. North American nonparasitic lamprey of the family Petromyzontidae must be

protected. Canadian Field-Naturalist 87:235-239. Whyte, J. N. C., R. J. Beamish, N. G. Ginther, and C. E. Neville. 1993. Nutritional condition of the

Pacific lamprey (Lampetra tridentata) deprived of food for periods of up to two years. Journal canadien des sciences halieutiques et aquatiques 50:591-599.

Wydoski, R. S., and R. L. Whitney. 2003. Inland Fishes of Washington. University of Washington

Press. Seattle, Washington.

19

TABLES Table 1. Numbers of radio-tagged adult Pacific lamprey organized by sex, collection location (LMO = Lower Monumental Dam, LGO = Little Goose Dam), release location (RWC = Red Wolf Crossing, LGF = Lower Granite Flood), and median release dates with corresponding means and standard deviations (SD) for fish size metrics.

Collection Release Tagging

Overall location location Length (cm) Girth (cm) Weight (g) dates

Year Sex N LMO LGO RWC LGF Mean SD Mean SD Mean SD Median (Range)

2006 M 19 6 13 12 7 67.3 4.4 10.6 0.9

F 29 10 19 12 17 68.1 3.4 10.9 0.6

U 2 2 2 69.3 1.8 11.0 0.4 15‐Aug

Total 50 16 34 26 24 67.8 3.7 10.8 0.7 (July 25‐Sept 19)

2007 M 17 2 15 17 63.9 4.5 10.8 0.6 431.0 64.8

F 20 5 15 20 66.9 2.6 11.3 0.7 493.0 84.3

U 9 3 6 7 2 63.7 4.2 10.5 0.8 414.6 81.8 18‐Aug

Total 46 10 36 44 2 65.1 4.0 10.9 0.7 454.7 82.9 (22‐July to 16‐Oct)

2008 M 23 2 18 20 65.9 2.6 10.9 0.6 430.6 36.5

F 20 3 20 23 66.8 3.6 11.2 0.6 470.6 63.9

U 7 2 5 7 65.9 4.4 10.7 0.8 409.8 91.1 18‐Aug

Total 50 7 43 50 66.3 3.3 11.0 0.6 447.2 62.1 (4‐Aug to 4‐Sept)

20

Table 2. Comparison of daytime adult lamprey counts at lower Snake River dams (Lower Monumental = LMO, Little Goose = LGO) and radio-tagging efforts from 2006 to 2008.

2006 2007 2008

LMO LGO LMO LGO LMO LGO

Adult daytime count 175 124 139 73 145 104

Median count date 29‐Jul 30‐Jul 12‐Aug 21‐Aug 8‐Aug 10‐Aug

Number tagged 16 34 10 36 7 43

Percentage of daytime count tagged 9.1 27.4 7.2 49.3 4.8 41.3

Median tag date 27‐Aug 11‐Aug 24‐Aug 14‐Aug 19‐Aug 18‐Aug

21

Table 3. Median and range of fall migration rates (km·day-1) for radio-tagged lamprey in Snake and Clearwater reaches from 2006 to 2008 organized by reach type (REL-FS or FS-FS), length (rkm), and gradient (m•rkm-1).

2006 2007 2008

# Reach Type Length Gradient N Rate (Range) N Rate (Range) N Rate (Range)

1 OFF‐CWR REL‐FS 58 0.24 2 1.0 (0.9‐1.0)

2 OFF‐SNR REL‐FS 67 0.06 2 15.6 (12.5‐18.8)

3 RWC‐CWR REL‐FS 10 1.30 10 0.3 (0.1‐16.0) 5 1.0 (0.2‐8.0) 21 2.2 (0.1‐31.1)

4 RWC‐CCR REL‐FS 127 1.26 1 4.2

5 RWC‐TOS REL‐FS 77 1.03 3 3.8 (1.2‐5.1) 1 4.1

6 RWC‐SNR REL‐FS 19 0.22 4 35.7 (1.9‐38.1) 6 13.5 (4.5‐41.1) 15 15.8 (4.4‐38.7)

7 CWR‐TOS FS‐FS 67 0.99 2 3.5 (1.7‐5.2) 1 9.6 13 8.5 (1.3‐34.1)

8 CWR‐CCR FS‐FS 116 1.26 1 17.0 2 9.9 (9.2‐10.6)

9 SNR‐CWR FS‐FS 9 1.05 1 2.4

10 TOS‐SFC FS‐FS 52 1.88 1 13.9 2 15.4 (13.5‐17.2)

11 TOS‐CCR FS‐FS 49 1.63 1 13.1 7 13.4 (12.5‐21.9)

12 TOS‐LOC FS‐FS 84 1.68 1 3.3

13 TOS‐SEL FS‐FS 86 1.69 1 16.4

14 CCR‐LOC FS‐FS 35 1.75 5 13.0 (5.5‐16.8)

15 CCR‐SEL FS‐FS 36 1.76 1 27.5 2 15.0 (12.3‐17.8)

22

Table 4. Median and range of detections at Snake and Clearwater River fixed-site receivers organized by fixed site receiver information, study year, and movement period (Fall and Spring). N = number of uniquely tagged lamprey. Receiver (#) corresponds to numbered symbol (1-20) located on Figure 1. Only fixed-site receivers with valid records are shown below.

Fall Spring

Receiver (#) River rkm Study year N Median (Range) N Median (Range)

CWR (1) Clearwater 232 2006 12 21‐Sep (29 Jul‐9 Nov) 6 13‐Mar (17 Feb‐17 Mar)

2007 6 8‐Sep (27 Aug‐22 Oct) 3 12‐Mar (12 Mar‐8 Apr)

2008 22 19‐Aug (9 Aug‐14 Nov) 8 21‐Mar (20 Feb‐24 Apr)

SNR (2) Snake 241 2006 6 9‐Aug (1 Aug‐25 Sep)

2007 6 12‐Aug (31 Jul‐7 Sep) 1 22‐Mar

2008 15 19‐Aug (6 Aug‐2 Jun)

TOS (4) Clearwater 299 2006 2 25‐Sep (23 Sep‐28 Sep) 3 21‐Mar (12 Mar‐9 Apr)

2007 4 20‐Sep (8 Sep‐14 Oct) 6 24‐Apr (3 Mar‐4 May)

2008 14 4‐Sep (21 Aug‐11 Oct)

IMR (8) Imnaha 331 2006 1 4‐May

CCR (9) MF Clearwater 348 2006 1 27‐Sep

2007 1 4‐Sep

2008 9 6‐Sep (23 Aug‐23 Sep)

SFC (10) SF Clearwater 351 2006 1 26‐Sep

2007 2 10‐Apr (6 Mar‐16 May)

2008 3 29‐Aug (24 Aug‐2 Jun)

LOC (11) Lochsa 383 2008 5 19‐Sep (31 Aug‐25 Sep)

SEL (12) Selway 385 2007 2 21‐Sep (6 Sep‐7 Oct)

2008 2 2‐Sep (27 Aug‐9 Sep)

23

Table 5. Annual detection rates and last known locations of individual radio-tags by river reach from 2006 to 2008. CWR = total tags found in mainstem Clearwater below the mouth of the S.F. Clearwater. SNR = total tags detected in mainstem Snake above and below Snake-Clearwater confluence. SAL = total tags found in mainstem Salmon.

Radio tag detections Reach

Year N N % CWR MFCR SFC LOC SEL SNR IMR SAL

2006 50 32 64.0 16 0 1 1 1 8 1 4

2007 46 37 80.4 21 2 1 0 2 6 0 5

2008 50 49 98.0 17 3 3 6 2 9 1 8

24

FIGURES

HC

LMO

Snake R.

Salmon R.

IHR

DWLGO

LGR

Clearwater R.Tucannon R.

Potlatch R.

Selway R.

Lochsa R.

SF Clearwater R.

Imnaha R.

Little Salmon R.

MF Salmon R.

SF Salmon R.

NF Salmon R.Grand Ronde R.

14 5

7

9

10

12

112

36

8

18

20

16 1917

13 1415

1

2

4

Lower Granite dam

OFF

WAI

RWC46° N

45° N

44° N

118° W 116° W 114° W

0 50 km

Clearwater R.

Snake R.

Lemhi R.

Pahsimeroi R.

Figure 1. Map of the lower Snake, Clearwater, and Salmon rivers showing the tagging locations (LMO = Lower Monumental Dam, rkm 67; LGO = Little Goose Dam, rkm 113), release locations (boxes), fixed-site receivers (grey circles), and U.S. Geological Society gage sites (stars). Hells Canyon (HC, rkm 398) and Dworshak Dams (DW, rkm 292) are also represented. Grey circles with numbers correspond to fixed-site receiver number and rkm (Full descriptions of fixed-site receivers are included in Appendix Table A-1): 1 = SNR (232); 2 = CWR (241); 3 = GRR (273); 4 = TOS (299); 5 = ORO (301); 6 = EON (304); 7 = LCR (312); 8 = IMR (331); 9 = CCR (348); 10 = SFC (351); 11 = LOC (383); 12 = SEL (385); 13 = MCR (396); 14 = JCR (401); 15 = TCR (420); 16 = NCR (430); 17 = CRO (440); 18 = LSR (442); 19 = AMR (447); 20 = PCR (645). Insets show the western USA and Canada: ID, Idaho; WA, Washington; OR, Oregon; BC, British Columbia and release locations above Lower Granite Dam (OFF = Offield, rkm 174; WAI = Wawawai, rkm 178; RWC = Red Wolf crossing, rkm 221).

25

Tem

pera

ture

(C)

0

5

10

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20

25

SNR 2006 SNR 2007 SNR 2008 CWR 2006 CWR 2007 CWR 2008

Month

Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May

Dis

char

ge (m

3 / se

c)

0

500

1000

1500

2000

2500SNR 2006 SNR 2007SNR 2008 CWR 2006 CWR 2007 CWR 2008

Figure 2. Mean monthly water temperature (°C, upper panel) and discharge (m3·sec, lower panel) at U.S. Geological Survey stations on the Snake River near Anatone (circles) and the Clearwater River near Spalding (triangles) in 2006 (black symbols), 2007 (white symbols), and 2008 (grey symbols).

26

0

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io-ta

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Lower Monumental 2006

Lower Monumental 2007

Lower Monumental 2008

Little Goose 2006

Little Goose 2007

Little Goose 2008

Figure 3. Number of adult Pacific lamprey counted passing Lower Monumental (left panels) and Little Goose Dams (right panels) via fish ladders (grey lines) and the number that were collected and radio-tagged (black bars) from 2006 to 2008.

27

Time of day

0

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Time of day

01:0

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Figure 4. Distributions of the times that radio-tagged lamprey were detected passing fixed-site receivers (SNR and CWR) in the Snake and Clearwater River basins in the fall (upper panel) and spring (lower panel) from 2006 to 2008.

28

Jul 06

Sep 06

Nov 06

Jan 07

Mar 07

May 07

Jul 07

Dat

e

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Nov 07

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Mar 08

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Jul 08

Time of day

00:00 04:00 08:00 12:00 16:00 20:00 00:00

Jul 08

Sep 08

Nov 08

Jan 09

Mar 09

May 09

Jul 09

A

B

C

Figure 5. Diel and seasonal timing of radio-tagged lamprey movement past Snake and Clearwater River fixed-site receivers (SNR and CWR) in 2006 (A), 2007 (B), and 2008 (C). Vertical solid lines represent sunrise and sunset near Lewiston, ID. Dotted horizontal lines represent periods of inactivity at fixed-site receivers. Each unique symbol represents an individual lamprey; many lampreys were observed at multiple fixed sites. Horizontal lines represent individual tags that held positions near fixed-site receivers during daylight.

29

Movement period

F S F S S-MBT F S S-MBT

Num

ber o

f ind

ivid

ual l

ampr

ey

0

5

10

15

20

25

30

35

40

45

50

CWR FSCWR MBTSNR FSSNR MBT

2006

2007

2008

Figure 6. Seasonal (F = fall, S = spring) distribution of F1 detections of unique radio-tagged lamprey in the Clearwater (CWR receiver) or Snake River (SNR receiver) drainages from 2006 to 2009. Stacked bars represent the number of lamprey detected via fixed-site (FS) or mobile telemetry (MBT).

30

Fixed-site receiver

SNR CWR TOS

Dat

e

2 Jul

23 Jul

13 Aug

3 Sep

24 Sep

15 Oct

5 Nov

26 Nov200620072008

6

615

12

5

22

2

4 14

Figure 7. Box plots showing median, mean (x), quartile, and 5th and 95th percentile of reach entry dates (F1 detections) of radio-tagged adult Pacific lamprey at Snake (SNR) and Clearwater River fixed-site receivers (CWR, TOS).

31

0.0

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Figure 8. Cumulative percentages of F1 radio-tag detections (dark solid lines), mean daily temperatures (solid lines), mean daily discharges (dashed lines), and daylight hours (dotted lines) on the Snake River in 2006 (A-B), 2007 (C-D), and 2008 (E-F). Temperature and discharge data were collected at the USGS gaging station near Anatone, WA (rkm 269). Telemetry data is from the SNR fixed-site receiver (rkm 241). Number of daylight hours range from 8-16 hours.

32

0.0

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Figure 9. Cumulative percentages of F1 radio-tag detections (dark solid lines), mean daily temperatures (solid lines), mean daily discharges (dashed lines), and daylight hours (dotted lines) on the lower Clearwater River in 2006 (A-B), 2007 (C-D), and 2008 (E-F). Temperature and discharge data were collected at the USGS gaging station near Spalding, ID (rkm 245). Telemetry data is from the CWR fixed-site receiver (rkm 232). Number of daylight hours range from 8-16 hours.

33

0

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ANA_date_06 vs ANA_temp_06 SPA_date_06 vs SPA_temp_06 ORO_date_06 vs ORO_temp_06

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(C)

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ANA_date_07 vs ANA_temp_07 SPA_date_07 vs SPA_temp_07 ORO_date_07 vs ORO_temp_07

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Figure 10. Relative river temperature (left panels) and discharge (right panels) encountered by radio-tagged Pacific lamprey in the Snake (black circles), the lower Clearwater (white circles, downstream of Dworshak Dam), and upper Clearwater (grey circles, upstream of Dworshak Dam) Rivers in 2006 (A-B), 2007 (C-D), and 2008 (E-F). Each symbol represents F1detection dates of individual lamprey at Snake (SNR, rkm = 241), lower Clearwater (CWR, rkm 232; TOS, rkm 299), and upper Clearwater (CCR, rkm 348) fixed-site receivers.

34

Mig

ratio

n ra

te (k

m/d

ay)

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50

2006 20072008

REL-CWR REL-SNR

Pas

sage

tim

e (d

ays)

0

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40

60

80

100

120

20062007 2008

Snake RiverClearwater River

Figure 11. Box plots showing mean (x), median (horizontal bar), quartile and 5th and 95th percentiles of adult Pacific lamprey migration rates (km/day) and passage times (days) from release through two reaches of the Clearwater and Snake rivers. REL, Red Wolf Crossing (rkm 222); CWR, Clearwater River near Lewiston, ID (rkm 232); SNR, Snake River near Asotin, WA (rkm 241).

35

HC

LMO

Snake R.

Salmon R.

IHR

DWLGO

LGR

46° N

44° N

45° N

118° W 116° W 114° W

Clearwater R.

Tucannon R.

Potlatch R.

Selway R.

Lochsa R.

SF Clearwater R.

Imnaha R.

Little Salmon R.

MF Salmon R.SF Salmon R.

NF Salmon R.Grand Ronde R.

1

1

11

2

4 6

43

1

1

61

0 50 km

N

HC

LMO

Snake R.

Salmon R.

IHR

DWLGO

LGR

46° N

44° N

45° N

118° W 116° W 114° W

Clearwater R.

Tucannon R.

Potlatch R.

SelwayR.

Lochsa R.

SF Clearwater R.

Imnaha R.

Little Salmon R.

MF Salmon R.SF Salmon R.

NF Salmon R.Grand Ronde R.

1

2

311

6 10

92

2

2007

0 50 km

N

HC

LMO

Snake R.

Salmon R.

IHR

DWLGO

LGR

46° N

44° N

45° N

118° W 116° W 114° W

Clearwater R.

Tucannon R.

Potlatch R.

Selway R.

Lochsa R.

SF Clearwater R.

Imnaha R.

Little Salmon R.

MF Salmon R.SF Salmon R.

NF Salmon R.Grand Ronde R. 3

6

23

3

9 3

9

2

1

5

30 50 km

N

Figure 12. Map of the lower Snake, Clearwater, and Salmon River drainages and the last known locations of radio-tagged Pacific lamprey (boxes) in study year 2006 (top panel, N = 32), 2007 (middle panel, N = 37), and 2008 (bottom panel, N = 49).

36

APPENDIX A

Table A-1. Locations of University of Idaho and US Fish and Wildlife Servive fixed-site receivers monitored within the Snake and Clearwater River drainages from 2006 to 2009. Receiver numbers correspond to grey circles with numbers in Figure 1.

Receiver (#) Monitored stream Location description rkm Latitude Longitude Ownership

CWR (1) Clearwater R. upstream of Potlatch Mill 232 46.425349 116.939200 UI

SNR (2) Snake R. upstream of Three Mile Island 241 46.296223 116.987279 UI

GRR (3) Grand Ronde R. upstream of mouth 273 46.073276 116.987134 UI

TOS (4) Clearwater R. near Nez Perce Tribal Fisheries office 299 46.464512 116.233676 USFWS

ORO (5) Orofino Cr. near Konkolville Mill 301 45.482530 116.206476 UI

EON (6) Salmon R. near Eye of the Needle rapids 304 45.861173 116.779630 USFWS

LCR (7) Lolo Cr. near USGS stream gauge 312 46.372252 116.161158 USFWS

IMR (8) Imnaha R. near Fence Creek 331 45.642299 116.837573 UI

CCR (9) Middle Fork Clearwater R. near Clear Creek 348 46.133610 115.949797 USFWS

SFC (10) South Fork Clearwater R. near Stites, ID 350 46.086630 115.975184 USFWS

LOC (11) Lochsa R. near USGS stream gauge 383 46.150556 115.586517 USFWS

SEL (12) Selway R. downstream of Roar Creek 385 46.119685 115.569482 UI

MCR (13) South Fork Clearwater R. downstream of Mill Creek 396 45.831690 115.934059 USFWS

JCR (14) South Fork Clearwater R. near Johns Creek mouth 400 45.825572 115.889394 USFWS

TCR (15) South Fork Clearwater R. near Ten Mile Creek mouth 420 45.806794 115.684222 USFWS

NCR (16) Newsome Cr. upstream of mouth 430 45.834238 115.609224 USFWS

CRO (17) Crooked R. near IDFG weir 440 45.821887 115.526693 USFWS

LSR (18) Salmon R. near Riggins, ID 442 45.431382 116.311239 UI

AMR (19) American R. downstream of Meadow Creek 447 45.818161 115.466705 USFWS

PCR (20) Salmon R. upstream of Panther Creek 645 45.340192 114.412230 USWFS

37

APPENDIX B

Table B-1 Last known locations of individual radio-tagged lamprey organized by drainage, date, rkm (from mouth of Snake River), and telemetry source (FS = fixed-site location, MBT = mobile tracked location) from 2006 to 2007. All distances measured in kilometers.

Last known location

Drainage Code Tag date Date rkm Description Source

CWR 100 25‐Jul‐06 20‐Oct‐06 232 FS

CWR 110 7‐Aug‐06 15‐Mar‐07 232 FS

CWR 112 7‐Aug‐06 9‐Nov‐06 232 FS

CWR 114 8‐Aug‐06 13‐Mar‐07 232 FS

CWR 138 27‐Aug‐06 17‐Mar‐07 232 FS

CWR 142 29‐Aug‐06 12‐Mar‐07 232 FS

CWR 144 7‐Sep‐06 1‐Feb‐07 248 MBT

CWR 146 11‐Sep‐06 1‐Feb‐07 260 MBT

CWR 125 15‐Aug‐06 20‐Dec‐06 260 MBT

CWR 105 30‐Jul‐06 1‐Feb‐07 266 MBT

CWR 111 7‐Aug‐06 12‐Mar‐07 299 FS

CWR 122 11‐Aug‐06 21‐Mar‐07 299 FS

CWR 134 24‐Aug‐06 10‐Apr‐07 299 FS

CWR 124 13‐Aug‐06 1‐Feb‐07 318 MBT

CWR 103 28‐Jul‐06 1‐Feb‐07 340 MBT

CWR 117 8‐Aug‐06 1‐Feb‐07 341 MBT

SFC 121 13‐Aug‐06 13‐Nov‐06 384 0.7 downstream highway 14/Mt Idaho cutoff MBT

SEL 113 7‐Aug‐06 14‐Nov‐06 411 at Selway Falls MBT

LOC 102 28‐Jul‐06 14‐Nov‐06 433 13.2 upstream Fish Creek mouth MBT

SNR 127 18‐Aug‐06 2‐Nov‐06 174 at release site MBT

SNR 129 18‐Aug‐06 1‐Feb‐07 174 at release site MBT

SNR 130 18‐Aug‐06 2‐Nov‐06 174 at release site MBT

SNR 107 31‐Jul‐06 22‐Nov‐06 221 at Red Wolf bridge near Clarkston, WA MBT

SNR 101 28‐Jul‐06 7‐Aug‐06 241 FS

SNR 109 31‐Jul‐06 1‐Aug‐06 241 FS

SNR 115 19‐Sep‐06 25‐Sep‐06 241 FS

SNR 137 27‐Aug‐06 29‐Mar‐07 241 FS

IMR 118 10‐Aug‐06 5‐May‐07 331 FS

SAL 123 11‐Aug‐06 17‐Nov‐06 442 0.3 upstream LSR fixed‐site receiver MBT

SAL 120 11‐Aug‐06 23‐Jan‐07 442 MBT

SAL 149 19‐Sep‐06 17‐Nov‐06 473 1.4 upstream from French Creek mouth MBT

SAL 108 31‐Jul‐06 15‐Nov‐06 611 at Corn Creek boat launch MBT

38

Table B-2. Last known locations of individual radio-tagged lamprey organized by drainage, date, rkm (from mouth of Snake River), and telemetry source (FS = fixed-site location, MBT = mobile tracked location) from 2007 to 2008. All distances measured in kilometers.

Last known location

Drainage Code Tag date Date rkm Description Source

CWR 88 21‐Aug‐07 27‐Aug‐07 232 FS

CWR 106 20‐Sep‐07 28‐May‐08 246 6.2 upstream I‐95 Moscow exit MBT

CWR 146 31‐Jul‐07 29‐Apr‐08 258 0.5 downstream Cherrylane bridge MBT

CWR 70 7‐Aug‐07 29‐Apr‐08 271 near Lenore bridge MBT

CWR 76 10‐Aug‐07 29‐Apr‐08 274 1.92 upstream Lenore bridge MBT

CWR 105 20‐Sep‐07 22‐May‐08 275 9.9 from Cherrylane bridge MBT

CWR 84 16‐Aug‐07 29‐Apr‐08 275 3.83‐3.85 downstream Canyon Creek MBT

CWR 74 9‐Aug‐07 22‐Apr‐08 275 2.9 upstream Lenore bridge MBT

CWR 148 25‐Jul‐07 29‐Apr‐08 277 2.85 downstream Canyon Creek MBT

CWR 95 27‐Aug‐07 22‐May‐08 284 2.5 downstream from Pinkhouse Hole MBT

CWR 97 31‐Aug‐07 29‐Apr‐08 284 1.5 downstream Pinkhouse Hole MBT

CWR 75 9‐Aug‐07 29‐Apr‐08 292 2.5 downstream Orofino bridge MBT

CWR 79 13‐Aug‐07 29‐Apr‐08 297 near Bills Auto Body, Orofino, ID MBT

CWR 96 27‐Aug‐07 30‐Apr‐08 299 FS

CWR 81 13‐Aug‐07 29‐Apr‐08 306 1.8 downstream Greer road cutoff MBT

CWR 107 16‐Oct‐07 5‐Jun‐08 314 0.6 upstream from Five Mile Creek MBT

CWR 101 10‐Sep‐07 22‐May‐08 322 6.2 downstream from Kamiah highway 12 bridge MBT

CWR 98 6‐Sep‐07 5‐Jun‐08 323 6.1 upstream from Five Mile Creek MBT

CWR 93 27‐Aug‐07 22‐May‐08 327 3.6 downstream Kamiah highway 12 bridge MBT

CWR 85 21‐Aug‐07 28‐May‐08 343 1.1 downstream Kooskia 13 interchange MBT

CWR 102 12‐Sep‐07 28‐May‐08 343 1.1 downstream from Kooskia 13 interchange MBT

MFCR 86 21‐Aug‐07 13‐May‐08 357 1.3 up Red Pine Creek, MFCR MBT

MFCR 78 10‐Aug‐07 13‐May‐08 380 1.0 downstream Selway/Lochsa confluence MBT

SFC 143 5‐Aug‐07 1‐Jun‐08 351 near Stites, ID MBT

SEL 104 16‐Sep‐07 28‐May‐08 411 0.5 downstream Gedney Creek Bridge MBT

SEL 142 5‐Aug‐07 28‐May‐08 411 0.5 downstream Gedney Creek bridge MBT

SNR 71 7‐Aug‐07 12‐Aug‐07 241 FS

SNR 73 9‐Aug‐07 12‐Aug‐07 241 FS

SNR 82 13‐Aug‐07 22‐Mar‐08 241 FS

SNR 94 27‐Aug‐07 28‐Aug‐07 241 FS

SNR 100 6‐Sep‐07 7‐Sep‐07 241 FS

NR 145 29‐Jul‐07 31‐Jul‐07 241 FS

SAL 77 10‐Aug‐07 19‐Apr‐08 476 0.5 upstream Fall Creek MBT

SAL 89 21‐Aug‐07 14‐May‐08 612 0.6 upstream Corn Creek mouth MBT

SAL 92 24‐Aug‐07 14‐May‐08 623 0.6 upstream Middle Fork Salmon RIver mouth MBT

SAL 87 21‐Aug‐07 14‐May‐08 636 8.2 upstream Middle Fork Salmon River mouth MBT

SAL 91 23‐Aug‐07 13‐May‐08 642 0.4 upstream Panther Creek MBT

39

Table B-3 Last known locations of individual radio-tagged lamprey organized by drainage, date, rkm (from mouth of Snake River), and telemetry source (FS = fixed-site location, MBT = mobile tracked location) from 2008 to 2009. All distances measured in kilometers.

Last known location

Drainage Code Tag date Date rkm Description Source

CWR 32 4‐Aug‐08 7‐Oct‐08 232 FS

CWR 34 5‐Aug‐08 14‐Mar‐09 232 FS

CWR 44 12‐Aug‐08 20‐Feb‐09 232 FS

CWR 54 18‐Aug‐08 15‐Jun‐09 244 2.6 downstream highway 12 bridge near Potlach River mouth MBT

CWR 36 6‐Aug‐08 19‐May‐09 247 0.9 downstream highway 12 bridge near Potlach River mouth MBT

CWR 76 3‐Sep‐08 19‐May‐09 254 near Mckay's Bend campground MBT

CWR 70 28‐Aug‐08 15‐Jun‐09 255 at Cottonwood Creek mouth MBT

CWR 64 25‐Aug‐08 4‐Jun‐09 256 0.2 upstream Cottonwood Creek MBT

CWR 66 25‐Aug‐08 4‐Jun‐09 260 0.8 upstream Cherrylane bridge MBT

CWR 65 25‐Aug‐08 4‐Jun‐09 268 1.8 downstream Lenore bridge MBT

CWR 33 5‐Aug‐08 20‐Mar‐09 271 0.1 downstream Lenore bridge MBT

CWR 58 18‐Aug‐08 15‐Jun‐09 271 0.4 up Lenore bridge MBT

CWR 80 4‐Sep‐08 4‐Jun‐09 286 3.0 upstream Big Canyon Creek MBT

CWR 49 14‐Aug‐08 4‐Jun‐09 287 near Pinkhouse Hole MBT

CWR 50 14‐Aug‐08 11‐Oct‐08 299 FS

CWR 53 18‐Aug‐08 15‐Jun‐09 330 6.37 upstream Six Mile Creek MBT

CWR 55 18‐Aug‐08 15‐Jun‐09 341 3.96 downstream highway 9 bridge MBT

MFCR 40 10‐Aug‐08 20‐May‐09 372 2.9 dn bridge creek, similar location MBT

MFCR 41 10‐Aug‐08 20‐May‐09 377 0.2 upstream Bridge Creek MBT

MFCR 77 3‐Sep‐08 20‐May‐09 377 2.5 downstream Selway/Lochsa confluence MBT

SFC 38 9‐Aug‐08 2‐Jun‐09 351 FS

SFC 35 6‐Aug‐08 14‐Apr‐09 369 3.8 upstream Grangeville/Mt Idaho cutoff MBT

SFC 48 12‐Aug‐08 29‐May‐09 374 7.0 miles upstream Grangeville/Mt Idaho cutoff MBT

SEL 39 10‐Aug‐08 7‐Jun‐09 384 FS

SEL 61 19‐Aug‐08 20‐May‐09 393 at O'hara Creek bridge MBT

LOC 78 3‐Sep‐08 13‐May‐09 425 3.2 upstream Fish Creek MBT

LOC 63 23‐Aug‐08 13‐May‐09 427 4.0 upstream Fish Creek MBT

LOC 47 12‐Aug‐08 13‐May‐09 428 5.3 upstream Fish Creek MBT

LOC 51 14‐Aug‐08 13‐May‐09 442 3.1 upstream Bald Mountain Creek MBT

LOC 37 9‐Aug‐08 13‐May‐09 446 5.5 upstream Bald Mountain Creek MBT

LOC 73 28‐Aug‐08 13‐May‐09 447 4.3 downstream Indian Grave Creek MBT

SNR 42 10‐Aug‐08 11‐Aug‐08 241 FS

SNR 52 14‐Aug‐08 15‐Aug‐08 241 FS

SNR 62 19‐Aug‐08 24‐Aug‐08 241 FS

SNR 68 26‐Aug‐08 30‐Aug‐08 241 FS

SNR 69 28‐Aug‐08 29‐Aug‐08 241 FS

40

SNR 71 28‐Aug‐08 31‐Aug‐08 241 FS

SNR 75 1‐Sep‐08 2‐Sep‐08 241 FS

SNR 59 19‐Aug‐08 20‐Aug‐08 248 15.9 downstream GRR fixed‐site receiver MBT

SNR 56 18‐Aug‐08 20‐Aug‐08 259 8.9 down GRR fixed site receiver, near Buffalo eddy MBT

IMR 46 12‐Aug‐08 1‐May‐09 344 7.4 upstream Imnaha fixed‐site receiver MBT

SAL 60 19‐Aug‐08 26‐Apr‐09 421 1.0 upstream John Day Creek MBT

SAL 43 12‐Aug‐08 26‐Apr‐09 434 1.0‐1.1 downstream Lightning Creek, at Chair Creek confluence MBT

SAL 67 26‐Aug‐08 15‐Jun‐09 437 1.0 downstream "time zone" bridge MBT

SAL 79 3‐Sep‐08 15‐Jun‐09 474 5.4 downstream Vinegar Creek launch MBT

SAL 45 12‐Aug‐08 26‐Apr‐09 479 2.7 downstream Vinegar Creek at Wind River bridge MBT

SAL 74 28‐Aug‐08 15‐Jun‐09 483 at Vinegar Creek MBT

SAL 57 18‐Aug‐08 20‐May‐09 642 0.5 upstream Panther Creek, mainstem Salmon R. MBT

SAL 31 4‐Aug‐08 20‐May‐09 647 3.5 upstream Panther Creek mouth, mainstem Salmon River MBT