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Kootenai River Fisheries Recovery Investigations KOOTENAI RIVER ECOSYSTEM REHABILITATION PROJECT.

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Presentation on theme: "Kootenai River Fisheries Recovery Investigations KOOTENAI RIVER ECOSYSTEM REHABILITATION PROJECT."— Presentation transcript:


2 Kootenai River Fisheries Recovery Investigations KOOTENAI RIVER ECOSYSTEM REHABILITATION PROJECT

3 Ecosystem disturbances 1)Diking of the river (loss of flood plain connection) 2)Channelization and some dredging (loss of habitat diversity) 3) Eutrophication 4) Mining (possible heavy metals) 5) Dam a. River regulation b. Temperature changes c. Nutrient trapping

4 Effects On Ecosystem : Nutrients Nutrients bind to sediment river productivity Libby Dam (1972) 63% of total P and 25% available N is retained by Libby (Woods 1982) 95% trapping efficiencies (Snyder et al. 1996)

5 Effects On Ecosystem : Primary Production Main source of bioenergetic development of higher trophic levels (Vanote et al. 1980; Allen 1995) Kootenai River P/R ratios < 1 indicating heterotrophic system (Snyder and Minshall 1996) Potential for autotrophic system if nutrient levels higher (Snyder and Minshall 1996)

6 Effects On Ecosystem : Secondary Productivity Pre-dam 3,520 insects/ m 2 (Bonde and Bush 1972) Post-dam 917 insects/ m 2 (Snyder and Minshall 1996) Lower densities than other Pacific Northwest systems (Holderman et al. 2000)

7 Community Type Change Degrading ecosystems: fish communities shift to habitat and feeding generalists (Karr 1991, 1995) (Mylocheilus caurinus) Shift from habitat and feeding specialist occurred in Kootenai River (Paragamian 1994) (Catostomus macrocheilus)


9 Are There Solutions? Ecosystem rehabilitation is needed to reverse declining fish populations (Holderman et al. 2001) In-river nutrification to stimulate productivity Increases in primary production would stimulate fish production (Snyder and Minshall 1996) Proven to be successful in fisheries management

10 Successful Nutrient Enhancement : Kootenay Lake : Increase escapement from 300,000 in 1991 to 2.1 million in 1998 (Ashley et al. 1997a) Arrow Reservoir : 99-00, kokanee abundance increased 4.4 million to 10 million (Holderman et al. 2001)

11 The Next Step? Pre-treatment Biomonitoring until 2004 Currently in feasibility faze: - Costs - Application - Location - Permitting - Public

12 Tanks treated with 0, 1.5, and 5 µm/L P Direct effects on fish community? Test hatch success and yolk absorption rate of white sturgeon larvae Preliminary results: no effect on hatching success

13 Angler Destination

14 Kootenai River White Sturgeon Recovery Investigations

15 Statement of the problem: The future of Kootenai River white sturgeon is in jeopardy Main reasons: 1) Ecosystem and habitat changes 2) Recruitment of wild sturgeon is limited 3) Nutrients may be limiting 4) Stock limitations and population trends 5) Overharvest

16 Flow during spring freshet lost - sturgeon spawning season

17 Shortys Island Kootenai River white sturgeon spawning reach rkm 228 to 246 Bonners Ferry Rkm 228 Rkm 246

18 Sampling mats were distributed from 1991 through 2001.

19 Examination of sturgeon eggs to determine age (h) and back calculate spawning date (event)

20 Increasing temperature decreasing flow 18 spawning events Flow Temperature 1996

21 Recommendations 1) Mitigated flows should follow local inflow 2) Maintain flows between 630 and 1,200 m 3 /s 3) Maintain stable or increasing temperatures o C

22 0.75 km upstream from Myrtle Creek Depth, in meters Spawning location

23 Habitat issue a limiting factor Survival bottleneck Hatchery juveniles 60% S year one 90% thereafter Thousands of eggs collected One Larvae collected Few wild juveniles

24 Chi square analysis p<0.01


26 Kootenay Lake elevations

27 Historic spawning reach?

28 0 Section K-18, above Deep Creek Left Bank Right Bank Gravel M.-C. Sand F. Sand Clay EXPLANATION Sand Pre-Libby Dam Lacustrine Clay Gravel

29 Proper temperature and flow mitigation will enhance white sturgeon spawning but the issue of spawning location and habitat and survival of eggs and larvae is still unresolved.

30 Population dynamics

31 How are we addressing the problem ?

32 Monitoring and Evaluation Set lining and angling Egg mats Larval sampling Radio and sonic telemetry Gill netting Trawling

33 Monitoring and evaluation

34 Net and jet program – unite sturgeon with better spawning habitat in upper river location

35 Net and Jet summary: 1)Brought 9 males and 3 females up to hemlock reach (rkm 262.0) 2) All females and 2 males radio and sonic tagged 3) 2 out of 3 females stayed in general area for a week or more 4)4 eggs found on substrate mats at rkm on June 5th. Unable to tell if eggs were fertilized 5) Additional research: pheromone drip station set up at rkm to help to keep males in the area of females

36 Dual beam SONAR (BIOSONICS) With fixed radio telemetry station 1) Estimate spawning stock 2) More behavioral data 3) Timing of migration

37 USGS subcontracts 1) Sedimentation transport why ? We need to know where sedimentation is occurring. Habitat improvement is futile if done in depositional areas. 2) Acoustic Doppler Current Profiling why? Sturgeon may be seeking out specific current velocities (versus substrate) and we need to know what these requirements are, and the relationship between lake elevation and micro current velocities (habitat improvement ramifications or larval stocking). 3) Bathymetric mapping – detailed account of river substrate and depth

38 Acoustic doppler current profile (ADCP) of Kootenai River Relationship between lake elevation and micro current velocities

39 Bathymetry mapping

40 Where are our best opportunities to improve spawning habitat ? 1)Rehabilitation of historic reach 2)Spawning channels/islands constructed in popular spawning locations 3) New ideas or thoughts?

41 Summary How are we addressing the problems ? 1) Mitigation flows from Libby dam – best possible conditions for successful spawning 2) High tech research from USGS contracts – determine optimal current velocities for spawning and best locations for habitat improvement 3) Net and Jet – unite sturgeon with better habitat, novel ways to promote wild recruitment 4) Depth sensitive telemetry – behavioral data and habitat improvement ramifications 5) Continued monitoring and evaluation – population level 6) Experimental studies – Dual beam SONAR

42 Kootenai River Rainbow and Bull Trout Research

43 Rainbow Trout Last major sport fishery left in the Kootenai River

44 The Problem The Kootenai River has: - low density trout population - low trout catch rates

45 Hypotheses: - Recruitment Limited -High Angling Exploitation -Nutrient Limited

46 Objective 1 Quantify rainbow trout recruitment (out-migrants) to the Kootenai River

47 Adfluvial stock Mature in Kootenay Lake Fluvial stock Spawn in Tributaries rear In river



50 Change in Regulations ???

51 Kootenai River Trout Regulations BagSizeBaitClosed LimitLimitRestrict.Season NoneNoneNone NoneNone

52 - Protect most fish until they can spawn at least once - Improve the size structure for a more quality fishery

53 Bull Trout Life History Investigations


55 O'Brien Cr., MT Bonners Ferry, ID ID-MT Border Kootenai Falls

56 Bonners Ferry, ID OBrien Cr. ID-MT Border


58 Recommended Flows for Burbot Spawning Migrations in the Kootenai River

59 In Idaho endemic only to the Kootenai River Once provided important winter commercial and sport fishery in Kootenai River and Kootenay Lake

60 Burbot Egg 1 mm in diameter Pelagic (open water) Feed on plankton As young grow in length they move to shoreline and feed on insects and small fish Burbot life stages and food Larger burbot move To deeper water and Feed on fish and shrimp Adults migrate to streams In winter and form spawning balls

61 Spawning synchrony (Arndt and Hutchinson 2000) Highly synchronized in timing of maturity and arrival to spawning habitat

62 Water velocity cm/second Burbot length cm Burbot swimming endurance (Jones et al. 1974) Even largest burbot Cannot sustain their swimming for 10 min after velocity reaches about 24 cm/s

63 Activity Jan April July Sept Dec Month Burbot Activity – time of year Paakkonen (2000) Spawning season

64 Burbot are capable of moving long distances (120 km) but they are slow

65 Winter flow Post Libby Dam Pre Libby Dam Libby Dam 1972 Bonners Ferry Burbot Time 1973

66 Lake Koocanusa Libby Dam (rkm 352) Kootenai Falls (rkm 310) Yaak River Moyie River Deep Bonners Ferry (rkm 246) Boundary Cr. Goat River (rkm 170) Nelson Duncan Lake Kootenay Lake South Arm West Arm North Arm (rkm 120) Creek 050 Kilometers BRITISH COLUMBIA MONTANAWASHINGTONIDAHO rkm 228 N S EW Primary burbot study area Goat River Only known Consistent Spawning site

67 Sensitive Life History Factors (1)Low swimming endurance (2)Winter spawners - highly synchronized (3)In Kootenai River must travel long distances (Kootenay Lake and lower river), up to 120 km. (4)Larvae need immediate source of food (winter)

68 Objectives Determine the population status of burbot in the Kootenai River (1)Size structure (2)Distribution (3) Abundance (4) Movement (winter telemetry)

69 Burbot travel and river location Time December January February Flow from Libby Dam Burbot movement Flow Spawning season - telemetry

70 Objectives 1995-present 1)Determine genetic differences 2)Estimate population size 3)Determine blood physiology (stress) 4)Determine flow vs. movement relationships

71 Test Test Test Controlled flow tests Hypothesis h : Libby Dam flows do not inhibit burbot spawning migration simulate pre-dam o

72 Results of three low flow tests during the winter of (1)Significantly more movement during low flow - movement started in late October but more movement in January (need 90 days for migration)

73 A Conservation Strategy was prepared but flow recommendations were necessary for the next step- A Conservation Agreement.

74 Rate/day and distance Test Hypothesis h : flow from Libby Dam does not impair Burbot travel rate or distance. o

75 Rate/day and distance Test no tests

76 Test – only 3 days Search for an alternative method to determine suitable flows for burbot migration !

77 (1)Search all burbot telemetry records from (68 burbot with transmitters). (2) Examined all telemetry records – 1,835 contacts. (3) Travel rate criteria based on distance from Kootenai River in British Columbia to spawning tributaries in Idaho (~ 45 km) and a total travel time of 90 days. Criteria- Burbot must travel 5 km or more in 10 days or less. Stepwise movement

78 Stepwise movement – Flow range (m /s) Number of cases Total 44 3

79 Spawning migration and spawning Examined all stepwise movements of burbot and flow in two class intervals, Oct-Feb only Cases of Cases of (m /s) movement flow days (m /s) Fisher exact test (p = 0.001) 33

80 Flow Burbot spawn 1)Flow of 176 m /s from Libby Dam 2)For period of 90 d 3 Recommendations Burbot migration

81 Examination of temperature and burbot behavior Fidelity for Goat River Free ranging transboundary

82 New ideas for rehabilitation? 1)Use donor stocks 2)Use a captive signal stock to a. Concentrate spawners b. Establish spawners in individual tributaries c. Rehabilitation measure with wild fish – improve recruitment

83 Goal: Rehabilitate the Kootenay River stock of burbot in Idaho to population abundance that can sustain a harvest of surplus fish.

84 Objective: Determine the extent of the spawning stock of burbot in selected tribs. Objective: Determine if burbot spawner numbers can be concentrated with a signal Stock of burbot. Objective: Use a donor stock of burbot to Enhance recruitment - burbot are stock limited

85 Experiment with tributaries AB C Weir Captive fish

86 An International Conservation Strategy has been prepared What is next? (1) A Conservation Agreement is needed now. Implementation of Recommended flows from Libby Dam during winter could range from 100 – 300 m /s but must average about 176 m /s for 90 days (Nov-Jan)

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