Whirling Disease (Myxobolus cerebralis) and Idaho Fisheries Keith Johnson Ret’d Supervisor, IDFG...
44
Whirling Disease (Myxobolus cerebralis ) and Idaho Fisheries Keith Johnson Ret’d Supervisor, IDFG Fish Health Program Eagle Fish Health Laboratory Eagle, Idaho
Whirling Disease (Myxobolus cerebralis) and Idaho Fisheries Keith Johnson Ret’d Supervisor, IDFG Fish Health Program Eagle Fish Health Laboratory Eagle,
Whirling Disease (Myxobolus cerebralis) and Idaho Fisheries
Keith Johnson Retd Supervisor, IDFG Fish Health Program Eagle Fish
Health Laboratory Eagle, Idaho
Slide 2
Slide 3
Myxobolus cerebralis Life Cycle: salmonid tubifex
triactinomyxon myxospores
Slide 4
Slide 5
DOCUMENTED INTRODUCTIONS OF M. cerebralis-POSITIVE TROUT INTO
IDAHO WATERS. 1985-87. Lost River Trout Farm. Rainbow trout from
California. 1993 & 2004: Canyon Spring Trout Farm. Rainbow
trout from Utah. * *Have apparently not lead to established
infection. 1966-75. Nevada Div. Wildlife. Rainbow trout from
Truckee National Hatchery stocked into streams that cross the state
border. 1986. Palouse area farm pond. Rainbow trout from northeast
Oregon.*
Slide 6
Susceptibility of Salmonid Species To M. cerebralis
Slide 7
Slide 8
Dynamic Relationship of Host/Parasite/Environment HOST
ENVIRONMENTPARASITE HOST PARASITE ENVIRONMENT HOST PARASITE
Presence, No Disease: M. cerebralis spores rare, no disease signs,
host population resilient Ex: S.F. Snake R, S.F. Boise R, M.F.
Salmon R Disease, No Impact: Prevalence and intensity of infection
high, disease signs occasional, host population resilient Ex: Big
Wood R, upper Salmon R, Lemhi R Negative Population Impact: Spores
and pathology abundant, disease signs common, host population is
parasite limited Ex: Big Lost R, Little Lost R, Pahsimeroi R
Slide 9
Idaho Department of Fish and Game Hatcheries Sawtooth
Pahsimeroi
Slide 10
Figure 1. Prevalence and intensity of M. cerebralis infection
of sentinel rainbow trout exposed for ten days to the Salmon River
water supply of Sawtooth Hatchery, Feb, 2000-Jan, 2001. Prevalence
(%)0 0209588 80 95855519135 Degrees C2.6
3.66.17.211.214.113.011.47.13.32.93.2 Hydrograph (CFS)110
11025015702190470341304258180123118 7 5 22 53 88 5 22 23 54 109 50
139 5 7 144 24 15 4 44 6 2. 10
Slide 11
Figure 2. Prevalence and intensity of M. cerebralis infection
of sentinel rainbow trout exposed for ten days to the river water
supply of Pahsimeroi Hatchery, Feb, 2000- Jan, 2001. Prevalence (%)
6785 100 10090 100 100 80 100869180 Degrees C 5.0 6.4 9.2 10.3 12.0
13.1 13.5 11.9 9.35.83.23.4 Hydrograph 329 327 300 135 133 109 175
175 284300311321 56 26 102 4 7 68 46 25 6 7 21 143 52 127 8 17 266
194 25 3 58 19 4 15 1 139 53 28 3 2 23 43 4 15 52 140 5 18
Slide 12
Effect of delaying exposure of Chinook juveniles to river water
at Sawtooth and Pahsimeroi hatcheries on detection of M. cerebralis
at pre-release sampling the following spring. E xposure Date
Slide 13
Detection of M. cerebralis from Chinook and steelhead adults at
Upper Salmon River trap locations. Return years 1987-2006. Return
Years
Slide 14
UPPER SALMON R
Slide 15
Distribution of Myxobolus cerebralis within the Salmon River
during the migration period of 2001 for juvenile anadromous
salmonids Wade Cavender JAAH 2003
Slide 16
Snake River 1 2 NF Salmon River 3 4 5 6 7 8 9 10 EF Salmon
Lemhi R. Pahsimeroi R.
Slide 17
April EF Salmon Pahsimeroi R. Snake River NF Salmon River STFH
PFH OFH Lemhi R. 60% 0% 100% 15% 100%
Slide 18
May EF Salmon Pahsimeroi R. Snake River NF Salmon River STFH
PFH OFH Lemhi R. 100% 90% 100% 20% 15% 100%
Slide 19
Myxobolus cerebralis Observations in Natural Steelhead and
Chinook for the Period 1987 2006 Organized by IDFG Regions REGION
STEELHEAD CHINOOK Clearwater 0/301 0/428 Southwest 0/57 0/493
Salmon 22/192 (11.5%) 262/2066 (12.7%)
Slide 20
Implications of Tributary Reconnection to Establishing
Myxobolus cerebralis in the Lemhi River Drainage, Idaho Keith
Johnson and Tom Curet Eagle Fish Health Laboratory and Salmon
Region Idaho Department of Fish and Game
Slide 21
Lemhi Exposure I June 03 Positive Negative
Slide 22
100% Hayden Cr Lemhi Exposure II Oct03 Positive Negative
Slide 23
Reconnection of Lemhi River Tributaries: Would not expand the
existing range of the parasite since it is already present,
regardless of tributary connection status Basin Creek may be the
origin of infectivity in the Hayden Creek drainage but ponds a
source also
Slide 24
Does M. cerebralis limit natural Trout production in the Teton
River ? Martin Koenig Utah State University Application of the UofI
epidemiological model of Anlauf, Colvin, & Moffitt
Slide 25
Fox Creek Trail Creek Teton Creek Teton River Teton R. Flow
Teton I exposure (Aug,03) prevalence and intensity (x000) of M.
cerebralis infection
Slide 26
Anemic challenges in the first Teton River exposure indicate a
low probability that M. cerebralis infections could limit natural
production of salmonids.
Slide 27
Fox Creek Trail Creek Teton Creek Teton River Teton R. Flow
Teton II exposure (July,04) prevalence and intensity (x000) of M.
cerebralis infection 100 (40) (69) (16) 50 (2) (23) (39) (18) (41)
Unnamed Creek
Slide 28
Implications from Teton River Trials Exposures made in 2004
resulted in higher prevalence and intensity of M. cerebralis
infection than in 2003, annual variation in exposure must be
considered Habitat differences throughout study area varied only
slightly Population declines were apparent in Yellowstone
cutthroat, not rainbow trout even though both species are highly
susceptible Tubifex habitat characteristics and susceptibility
lineages are needed Unnamed Creek may provide fry a refuge from
intense challenge
Slide 29
Application of Risk Assessment to Whirling Disease in Idaho
Introduction Isolation of new waters, prevent movement
Establishment & Amplification Need an understanding of what
environmental mechanisms operate to limit parasite numbers
Persistence Need to demonstrate the probability that M. cerebralis
will not persist and in what time period, the incentive for painful
change
Slide 30
Persistence of M. cerebralis: Will the infection fade into the
sunset? Modin (1998) reported infections decreased to below
detectable limits when positive rearing facilities in California
were closed in 3 of 22 waters over a 32-year period Cache de Poudre
River (Colorado Division of Wildlife) infections were no longer
detectable two years after an earthen rearing pond ceased rearing
trout (Nehring, 2003) Hayspur Hatchery (IDFG) switched to well
water in 1993 and we can no longer detect the parasite These
examples show the parasite may not persist in certain waters and
support enforcement of IDFGs role in private pond management
Slide 31
PROBABLE INFLUENCE OF IRRIGATION WATER DIVERSION ON Myxobolus
cerebralis-INFECTIVITY AT HAYSPUR HATCHERY AND IN LOVING CREEK, A
TRIBUTARY TO SILVER CREEK IN SOUTH CENTRAL IDAHO
Slide 32
Gannett Bellevue Loving Creek Stalker Creek Hayspur Hatchery
Silver Creek 5 km Big Wood River N S WE
Slide 33
HISTORY OF HAYSPUR HATCHERY Built 1906. Peak annual production
of 1 million rainbow trout fingerling and 350,000 rainbow
catchables. Myxobolus spores first detected from adult fish in the
brood pond in 1988; confirmed M. cerebralis in 1989. Reconstruction
began in 1989. All use of surface water for production ceased in
1995.
Slide 34
SENTINEL EXPOSURE DATES 4/036/039/033/045/046/0410/04 HATCHERY
INTAKE XXXX BROOD POND XXXX GAVER LAGOON XXXX RAILROAD TRESTLE
XXXXXXX KILPATRICK BRIDGE XXXXXXX IRRIGATION CANAL X X BIG WOOD
RIVER XX X EXPOSURE SITES
Slide 35
Gannett Bellevue Loving Creek Stalker Creek Hayspur Hatchery
Silver Creek 5 km Big Wood River N S WE Gaver Lagoon Kilpatrick
Bridge Railroad Trestle Brood Pond Intake Irrigation Canal Big Wood
River 7 exposures; 0/217 fish 2 exposures; 80/81 fish (99%) 3
exposures; 64/112 fish (57%) 7 exposures; 0/197 fish 4 exposures;
0/133 fish 4 exposures; 0/101 fish 4 exposures; 0/122 fish Hayspur
Hatchery sites
Slide 36
Gannett Bellevue Loving Creek Stalker Creek Hayspur Hatchery
Silver Creek 5 km Big Wood River N S WE Kilpatrick Bridge Railroad
Trestle Intake Irrigation Canal 2 exposures; 0/86 fish 1 exposure;
47/47 fish (100%) 2 exposures; 1/84 fish 2 exposures; 0/88 fish 2
exposures; 0/75 fish 2006 Heavy snowpack = extended runoff Loving
Creek Diversion
Slide 37
Conclusions from the Hayspur Hatchery Exposures: M. cerebralis
detections at Hayspur H. during the 88- 93 period was sporadic and
low in prevalence (
CDOW 09 Hofer X CRR RBT Hybrid Evaluations Hybrids and CRR
controls stocked in two river systems for four years Hybrids had
higher survival than CRR controls Post-stocking survival was best
when stocked at >9 TL to avoid predation by BNT Some natural
reproduction has been detected in both rivers Hofer genetic markers
have exceeded CRR markers in natural fry CDOW will continue
stocking hybrids and monitoring natural production of hybrids vs
controls
Slide 41
So now I get to speculate on why whirling disease does not
cause levels of impact in Idaho as reported in MT and CO. Habitats
within the shaded area in which population impacts are suspected
are all: Volcanic tuft soils, easily eroded Abundant groundwater,
stable water temperature Eutrophic, highly productive High level of
grazing impacts Low gradient river bottoms Tubifex habitat and
lineages are important to examine
Slide 42
HOST ENVIRONMENTPARASITE HOST PARASITE ENVIRONMENT ? Shaded
drainages have aquatic habitats conducive to amplification:
Pahsimeroi, Lemhi, Big & Little Lost, Birch Creek, and Teton R
on a bad year Drainages outside of the shaded area are basaltic and
granitic origin, lack amplification after parasite was
introduced
Slide 43
PLANS FOR THE FUTURE Expand knowledge on distribution and
epidemiology of M. cerebralis: Upper Salmon River and role of
carcasses Cooperate with ISDA and industry to reduce WD range and
intensity through Invasive Species legislation Administer private
pond stocking to reduce risk of parasite spread Monitor Hofer RBT
resistance research and explore application for Idaho Educate
regional biologists, conservation officers and anglers about
whirling disease
Slide 44
Thanks to Idaho Power Company for this $12 M investment!