parasitic copepods (salmincola sp.) and fish species ... · copepods •salmincola prevalence...

Parasitic Copepods (Salmincola sp.) and Fish Species Composition in Upper Willamette Reservoirs

Jeremy D. Romer* Ryan Emig*

Fred R. Monzyk

Oregon Department of Fish and Wildlife Corvallis Research Lab

[email protected]

2. Compare Fish Community Among Upper Willamette Reservoirs. •Numbers of Native and Introduced Species •Relative abundance •Possible effects on juvenile spring Chinook •Management implications

1. Present Observations of Gill Parasites (Salmincola sp.) in Cougar and Detroit Reservoirs.

2. Fish Community in Upper Willamette Reservoirs

1. Gill Parasites

Gill Nets Oneida Traps Boat E-fishing

Screw Trapping Below Cougar Reservoir.

Juvenile Spring Chinook Captured Below Cougar Dam

40

60

80

100

120

140

160

180

200

26-Jun 16-Jul 5-Aug 25-Aug 14-Sep 4-Oct 24-Oct 13-Nov 3-Dec 23-Dec

NO Copepods

Copepods PRESENT

Jul 21%

Sep 31%

Oct 74%

Nov 76%

Dec 91%

Aug 9%

Fork

Len

gth

(m

m)

Date

Juvenile Spring Chinook Captured Below Cougar Dam

Map with snorkeling sites marked above the Res

0

10

20

30

40

50

60

70

80

90

100

Jul Aug Sep Oct Nov Dec

SF McKenzie River

Below Dam

N= 14

N= 16

N= 417 N=60

Juvenile Spring Chinook Upstream vs. Downstream of Cougar Res.

Month

Perc

ent

Infe

cted

N= 689 N= 87

N= 32

N= 87

Juvenile Spring Chinook Captured Below Detroit Dam

Date

Nov 70%

Dec 53%

40

60

80

100

120

140

160

180

200

220

26-Jun 16-Jul 5-Aug 25-Aug 14-Sep 4-Oct 24-Oct 13-Nov 3-Dec 23-Dec

No Copepods

Copepods Present

Map with snorkeling sites marked above the Res

0

10

20

30

40

50

60

70

80

90

100

Sep Oct Nov Dec

Breitenbush River

North Santiam River

Below Dam N= 71

N= 9

N= 112

N= 32

S. californiensis from masu salmon (photo S.Urawa)

S. Edwardsii (Olsson 1969)

Perc

ent

Infe

cted

2. Compare Fish Community Among Upper Willamette Reservoirs. •Numbers of Native and Introduced Species •Relative abundance •Possible effects on juvenile spring Chinook •Management implications

Species Composition in Upper Willamette Valley Reservoirs

Species Number captured Size (mm)

Detroit Cougar Lookout Point Min. - Max

Native Rainbow Trout (Oncorhynchus mykiss) 1880 132 198 36 - 440 Cutthroat Trout (Oncorhynchus clarkii) 1 73 39 67 - 394

Bull Trout (Salvelinus confluentus) 0 12 0 215 - 537 Mountain Whitefish (Prosopium williamsoni) 13 158 1 33 - 330

Northern Pikeminnow (Ptychocheilus oregonensis) 0 0 577 33 - 590 Sucker (Catostomus spp.) 0 0 527 60 - 565 Dace (Rhinichthys spp.) 14079 28707 62 31 -95

Redside Shiner (Richardsonius balteatus) 0 0 357 52 - 113

Sculpin (Cottus spp.) 5 4 53 46 -223

Exotic Kokanee (Oncorhynchus nerka) 400 0 0 42 - 165

Bass (Micropterus spp.) 0 8 160 30 - 475 Walleye (Sander vitreus) 0 0 26 187 - 755

White Crappie (Pomoxis annularis) 0 0 271 47 - 380 Black Crappie (Pomoxis nigromaculatus) 0 0 6 75 - 290

Bluegill (Lepomis macrochirus) 127 0 11 53 - 170 Pumpkinseed (Lepomis gibbosus) 5297 0 3 64 - 135

Brown Bullhead (Ameiurus nebulosus) 254 0 89 25 - 395 Yellow Bullhead (Ameiurus natalis) 0 0 9 120 - 260

Detroit Reservoir

Detroit Dam Tailrace

457 mm, 18 in.

178 mm, 7 in.

Photo: Greg Gilham

Cougar Reservoir

Lookout Point Reservoir

470 mm, 18.5 in.

755 mm, 29.7 in.

USGS 2004

Copepods •Salmincola prevalence appears to increase with the duration

of time spent in reservoirs. • Copepod infection seems rare in stream-rearing juveniles.

•Need information on how copepods affect saltwater transition (physiology, parasitology). •Need standardized protocol to record intensity of infection. •Are fish infected in the reservoir? •Do Salmincola negatively affect survival?

Species Composition •Large abundance of piscivorous predators in Lookout Point Reservoir.

•Currently processing diet samples collected in Spring and Fall 2011.

•Drawdown in Lookout Point could decrease abundance of predatory fish. •Downstream effects ?

•Detroit Reservoir - Hatchery Rainbow Trout prey on juvenile Chinook •stream, reservoir, below the dam

Doug Garletts Chad Helms Greg Taylor Rich Piaskowski

Jeff Ziller

Randy Wildman

The ‘Reservoir Dogs’ Khoury Hickman David Duckett Chris Abbes Dave Metz Kris Clemons Shelly Goff Greg Gilham Mario Minder

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Cougar

Detroit

Lookout

Cougar

Detroit

Lookout

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aptu

red

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ree

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elsi

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parasitic copepods (salmincola sp.) and fish species ... · copepods •salmincola prevalence...

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