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Northern Pikeminnow Management Program

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Presentation on theme: "Northern Pikeminnow Management Program"— Presentation transcript:

1 Northern Pikeminnow Management Program
State goal. Project

2 Cooperators Outline Background Fisheries / Harvest Evaluation
What’s New Accomplishments BPA WDFW ODFW PSMFC

3 Background JOHN DAY RESERVOIR (1983-86) Losses to predation
Diet, salmonids Population An analysis of April – August predator diet composition indicated that although j-sals were consumed by all 3 predators; they were main prey item selected by NPM. Predator population estimates projected the size of the piscivore ~135,000 individuals – of which almost 2/3rds were NPM. The long and short of it is, based on these 2 things, they were able to estimate that ~1.4 million smolts were consumed by preds annually in the JD reservoir - 78% of which were consumed by NPM.

4 John Day Reservoir (continued)
Northern pikeminnow predation increased with size Move quickly through some background that led to the project, some history/accomplishments, then plans for

5 Background SYSTEM-WIDE (1990-92) Loss to Predation = 8% of Population
Predation Relative to John Day Reservoir Below Bonneville Dam = 800% Lower Columbia Reservoirs = 325% Lower Snake River Reservoirs = 40% Loss to Predation = 8% of Population

6 Background 10-20% Exploitation = 50% Reduction in Predation
Assumes no compensation by remaining predators: abundance, growth, fecundity, age structure, et al. Fisheries implemented systemwide in 1991 This came from evaluation.

7 Program Area                                                                                                           Priest Rapids Dam Hell’s Canyon Dam

8 Fishery Implementation and Harvest
Incidental catch of returning NPMP anglers

9 Dam Angling (ODFW, CRITFC, et al.) Gill Net (CRITFC, YIN, et al.)
Northern Pikeminnow Fisheries Sport Reward (WDFW) 1991-Present Dam Angling (ODFW, CRITFC, et al.) Gill and Dam: 159,000 Gill Net (CRITFC, YIN, et al.)

10 Sport Reward Harvest, Average 174,107; record harvest 2004, 267,215

11 Sport Reward Effort, 1991-2005 Angler Days (in thousands)
Average 40,258 angler-days/year. Peak 1992, 88,495

12 2005 Sport Reward Harvest by Reservoir
Below Bonneville 87,575 Ice Harbor 1,732 Bonneville 55,097 Lower Monumental 1,983 The Dalles 30,153 Little Goose 33,828 John Day 328 Lower Granite 12,073 McNary 18,588 Harvest by Reservoir

13 Sport Reward Incidental Catch, 2005
Family Catch (N = 96,790) Harvest (N = 10,964) % Acipenseridae 7.2 1.4 % Catostomidae 2.9 2.0 % Centrarchidae 20.2 14.5 % Clupeidae 0.8 1.8 % Cottidae 2.6 % Cyprinidae 54.7 55.8 % Ictaluridae 7.3 11.9 % Percidae 2.1 8.5 % Percopsidae <0.1 % Pleuronectidae 0.7 0.4 % Salmonidae 0.6 Incidental catch of returning NPMP anglers

14 Evaluation Incidental catch of returning NPMP anglers

15 Northern Pikeminnow Exploitation,
Sport Reward (> 250 mm FL),

16 Predation Relative to Pre-NPMP
Median reduction in predation based on Friesen and Ward’s (1999) model. Net gain estimated at 3.8 million smolts. 78%

17 Compensation? Abundance, density, age, growth, fecundity, consumption, condition Northern Pikeminnow No Smallmouth Bass Maybe SMB Relative density increases in certain areas Walleye No

18 Northern Pikeminnow Electrofishing Catch Rates, John Day Reservoir

19 Diet Composition (samples with identifiable fish),
Columbia and Snake Rivers, 1999, Family Northern pikeminnow (N = 291) Smallmouth bass (N = 364) % Salmonidae 69.7 20.7 % Cottidae 10.0 53.0 % Clupeidae 8.8 0.9 % Cyprinidae 3.2 7.2 % Catostomidae 0.0 6.3 % Cobitidae 0.2 % Ictaluridae 1.6 % Percopsidae 1.9 % Gasterosteidae 7.5 4.9 % Centrachidae 0.6 3.0 % Percidae 0.5

20 SMB Consumption Index – John Day Forebay
This SMB consumption index takes into account inputs such as stomach contents, fish wt., and temperature. Considering the increases in SMB relative density in the forebay area of the reservoir I’d thought we’d take a look at how many jsals are being consumed by SMB in this area. Consumption of smolts by SMB does not appear to have increased in the forebay in either spring or summer, and may actually be decreasing, slightly, on a per bass basis.

21 Age 4 and 5 SMB, Below Bonneville Dam

22 Recent Changes and Plans for 2006
Institutionalize Reward Structure Rolling Biological Indexing Re-institute Dam Angling Update Predation Model Multi-year Exploitation Rates Addition of Two Sport-reward Stations Rewards. Indexing in response to Bi-Op. Limited Dam angling by USDA on test basis. Respond to program review w/updated model and exploitation. New stations in Umatilla and Cascade Locks

23 NPMP Accomplishments, 1991-2005
Over 2.7 million Northern Pikeminnow Removed Low Impact to Resident / Anadromous Species >10% Exploitation Achieved in 13 of 15 Years Estimated 22% Reduction in Salmonid Predation Compensation by Remaining Predators Minimal Credible Science: ~30 Journal Articles Published Cost Effective Multiple audits, biological and economic, all concluded the program was efficient (with tweaks)


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