Table Of ContentWhirling disease
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disease questions
WWlingjclisease an
Q: is there a human health risk associated with
whirling disease?
A: There are no reports of humans suffering ill Late in 1994, Montana Fish, Wildlife & Parks announced that whirling
ecfofmecitnsgfirnomcoenittahcetrweiatthintghienpfaercatseidtef.ish or from disease was the suspected cause ofa 90 percent decline in the upper Madison
Rivers wild rainbow trout population. Whirling disease is a parasitic and
AQ:: AArtethoitshetirmea,nitmhaelisllinnessthies beenlviievreodnmtoenontlyafaffefecctted? potentially fatal infection oftrout & salmon for which there is no known cure.
trout and salmon.
Q: Is there a cure? It is certain that the wild rainbow trout popu-
A: At this time, there is no known cure for whirling lation in the 56-mile stretch of the Madison COMPARISON OF TROUT POPULATIONS
disease. Prevention is the only protection. River between Quake Lake and Ennis Lake IN SOME BLUE RIBBON MONTANA RIVERS
Q: How did whirling disease get to the Madison? has declined from about 3.300 fish per mile in
A: Because whirling disease is not indigenous to 1991 to about 300 per mile in 1994. What is 4; 3.ceo WD
Montana, and had never been detected here prior to uncertain is whether whirling disease caused Ed 2.500 IAfter nk
December. 1994. FWP suspects the likely origin is a direct mortality oftrout, or if its effects are 2 2.000
arinveirllneegaalritnhteroWdeuscttiFoonrokfolfivet,heinMfaedctiesdonf.ishAlilntkontohwen indirect in combination with other factors. m 1,500
infections in other states have been attributed
to the stocking of infected fish. While possible, it is In their search for answers. FWP fisheries £ 500
unlikely that the disease arrived in the Madison via biologists are now attempting to learn as S / f /
water contained in a fishing boat that moved from much as possible as fast as possible,about J*
a contaminated source in another state to Montana, whirling disease and how it functions
or via the feces ofa scavenger or predator that fed in the wild.
upon an infected trout.
Q: Where else has the disease been found? Meanwhile, the good news is the river's brown
A: Whirling disease occurs in much of Europe,where it trout have not experienced any unusual . • •*..»•.•••
probably originated. It was accidentaly introduced to declines. In fact, the Madison's total number
the United States in the mid 1950s when infected, of catchable wild trout still favorably com-
processed, and frozen trout arrived in Pennsylvania pares to other Montana Blue Ribbon trout
for the fish-market trade. The disease has subse-
streams, like the Big Hole, the Yellowstone.
quently been detected in the following 20 states: and the Gallatin rivers. NUMBER OF CATCHABLE SIZE TROUT MILE
Alabama. California. Colorado, Connecticut. Idaho.
Massachusetts. Michigan. Nevada. New Hampshire. PINE BUTTE VS. VARNEY
New Jersey. New Mexico. New York. Ohio. Oregon. Rainbow trout have historically comprised RAINBOW ==CW\
Pennsylvania.Virginia. Utah. West Virginia.Wyoming. more than halfof the upper Madison River's I
and most recently, in Montana. fishery immediately below Quake Lake, but as
Q: Can the spread of the disease be stopped? the river progresses toward Ennis. brown
A: Once the disease is in a river, there is no known trout--which have always offered the river's
way to stop its spread. largest and heaviest wild trout--begin to take
over. Near Ennis Lake, the upper Madison
9: Is the disease recognizable by anglers?
River's brown trout population has historically
A: Anglers probably won't detect the disease in any fish
they catch for two reasons: (1) the disease primarily comprised between 60 and 70 percent of the
affects young trout smaller than four inches in wild trout fishery. Today, the brown trout
length; anglers seldom observe these young trout; fishery remains healthy.
and (2) an infected fish's erratic tail chasing makes
it extremely vulnerable prey in the wild, so it is
unlikely that an infected fish would survive to grow
to a catchable size.
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is wliirlingf disease? prevention anJ control in tke wil liowyoucanneip
Whirling disease is caused by a microscopic, water- As yet no studies have been conducted to determine how Myxobolus Anglers, boaters and others may be able to
borne, protozoan parasite that attacks the cartilage of cevebralis(the protozoan spore that causes the illness) functions in the wild. FWP help prevent the spread ofwhirling disease by
ybroaulinsg) tarroeutr.eleWahsierdliinngtoditsheeawsaetseprorwehsen(Miynxfoebcotleudsficsehred-ie hopes to discover how the parasite moves from place to place in the wild, and if adhering to the following precautionary routines
and decompose, or are consumed and excreted by there is a way to contain its spread. after enjoying a day on the water.
predators or scavengers.
NORRIS
Tinhveolpvaersastihteethraosutaacnodmptlheexb,otttwoom--hdowsetllliifengcytculbeiftehxat troutpopulationanJ •BRIDGE anTdhaoxrloeus,ghwlaydecrhse,ckboyootus,r vaenhdiclfei,shbionagtg,eaanrcfhoorr,mutrdailtehrat
wthorromu,ghwohuitchMoinstfaonuan.d in streams, rivers, and lakes whirlingdiseasemonitoring cspoourleds.beWhholedninygoutubfiinfdexmwuodrmcslinagnidngwthoiryloiunrg edqisueiapsmeent,
FWP researchers have expanded trout population wash or scrape it off before departing the fishing
access site.
monitoring and whirling-disease testing in the
RESERVOIR
Madison River, its tributaries, and in other +Drain your boat and equipment ofall water. The
Montana river basins. As ofApril. 1995. the parasite may be present in water in your boat, cooler, or
disease has turned up in the Ruby River and live well, and could travel with you from place to place.
Poindexter Slough in southwestern Montana; in Do not transport any river or lake water in coolers,
Blaine Spring Creek, a Madison River tributary; V/iRNEY buckets or live wells from one river basin to another. The
and in Willow Creek, a Jefferson River tributary. BRIDGE whirling disease parasite is smaller than a grain of sand,
so even water that appears normal may be harboring the
The intensive disease-monitoring program is SPBRLNAONECREEK parasite. Make every effort to dry your boat and your
designed to track the downstream and upstream McATEE equipment between river trips.
movement of the disease, as well as to determine BRIDGE
if the disease exists in other Montana streams. WBILNMDAYCPCOEISNST Do not transport any live fish from one place to
another. In Montana, it is illegal to move live fish from
FWP's whirling disease and trout population .SQUAW one water body to other waters.
investigations will examine all trout age classes, LYON CREEK
follow populations through their lifecycles. and BRIDGE Do not dispose of fish entrails, skeletal parts, or other
While the parasite may not directly kill a trout, an thrreosuegahrcthheerslihfeocpyceletoofditshceovpaerrasaitwee.akInlitnhkisinwatyh.e bMyo-nptraondau.cts in any body ofwater. It is illegal to do so in
infected fish's erratic tail chasing makes it extremely lifecycle of the parasite, or. perhaps, a rainbow WEST FOR
vulnerable to predation. The whirling also causes fish trout strain whose immunity to infection may be
to be unable to feed normally, which can eventually passed on to future generations ofwild rainbow Do not transport aquatic plants. Remove all
result in starvation and death. trout. FWP also will attempt to determine how aquatic plants and weeds from your vehicle, boat, trailer
Tbehespdriesaedasiengisranpoidwlyfotuhnrdouignh2o0utsttahteesweasntderanppUenairtsedto wthhieteiflilsnhesasnadffKecotksagnreaeylisnagl,mocunttphorpoualtattiroonust., adenpdaratxilensg,tahnechfoisrh,inagnadccoethsesrsiatcec.essory equipment before
States. Unfortunately, how whirling disease functions
in the wild is not well understood. Most information
regarding whirling disease has been generated from
eqauxmepasettrtiieoennrcooeffshdweoibtwahtietfiaasfhmfeorcentasgrewfidilsdihn-thhreaoatulctthhperosippeueslc.iaatliIionsntfssa.cits,sttihlel raiTnobporwottercotutet,mthpaeongrMlaaidrniygsoroninv'esprosrcutlriovosinuvsrienosgf Hdriioesnwecaesa,reni,gavlraeeenrris-dmwrphioedorsewtpcaoirnntetdeaflatfscoepcewetnhcssitutrshlsoeifinrgFeWxPp'es- acInosotophleeurtmaietoainnottnihmreo,ugFhWrPesweilalr:chand WitKyoUurpassistance and cooperation,
Rainbow trout appear to be most susceptible to whirling the upper river was closed during the research. FWP will conducta river (1) continue its monitoring at state we can prevent the
disease infection, followed by sockeye salmon, golden traditional rainbow trout spawning wide creel census on the Madison hatcheries to ensure they remain
tsraolumto,nc,utAtthlranotaitctsraoultm,onb,roborkotwrnouttr,oustt,eealnhdeadc.ohcohinook season in the spring of 1995. during the "95 fishing season. d(i2s)eaagsgerefrseseivaenldy examine all waters in spread ofwhAig'disease in Montana,
salmon. Lake trout may be immune to the disease. To determine if angling pressure Montana for whirling disease parasite.
How it affects grayling, bull trout, mountain whitefish-- influences a recovery of the Madison scuilppiinnLan
and other fish--is unknown at this time. River's rainbow trout, a 4.5 mile stretch The collection of sculpins and/or their FWP also will participate in interna-
of the upper river between SquawCreek use as bait are prohibited inMontana. tional cooperative efforts to exchange dMoqtaqa Tisf^.
In Montana. FWP is seeking to decipher the relationship and the Windy Point fishing access site The ban came as anemergency pre- whirling disease information,expertise, I'WUdUfeCSL'ParKs
between wild trout and the whirling disease parasite. will be closed from March 1.1995. caution after sculpins taken from the and discoveries with other states and
The aim of FWP's research is to discover solutions through February 29. 1996. Madison were found to be carrying provinces and with the U.S. Fish &
through intensive study and scientific experimentaUon. spores resembling Myxoboluscerebralis Wildlife Service. 1420 E. Sixth Ave. Helena. Mt 59620 406-444-2535
