Matthew G. Mean,' Llma K. Wellar~d,U.S Geological Survey, Western Flsherles Research Csnter, Columbia Rlver
Research Laboratory, 5501A Cook-Und~rwoodRoad. Cook. Washinoton 88605
and
Gaylo Bsrbln Zydlewekl. U.S. Fish and Wlldllfe Servlce, Abernathy Fish TechnDlogy Center, 1440 Absrnathy Creek
Road. Longview. Washlngton 98632
Crltlcal Swlmmlng Spwds of Wild Bull Trout
Abstract
We en~irnnlcdt l criticd
~
swi~ilruinpspeods (UJ of wild bull trout nt 6", 1 l o , and 15°C in lnburutory cxpcriments. At I I "C. 5 fish
ranging from 11 to 19 cm in Icncth had FI mean Ur,, of 48.24 c n ~ l sor 3.22 body lengths p r ~econd(BUS).Alvo at 1 I T . 6 fish
from 32 to 42 cm had a mean Utmof 73.99 C ~ 01S2.05 BUS,A L 15"C, 5 fish from 14 to 23 cm hnd a man Uc, nf 34.M cmds or
2.88 BUG,No flrh aucceM'ully swnrn nr 6°C. Swim s p e d was signlflcmtly lntlucnced by fish length. Many buh Lrour prformed
poorly ill our c n c l o d rcspironlcters: of 71 U,,,tcsta we attempttxl, only the 16 describd v h v c were w c c a d u l . Bull trout that
d u m d to mudm held amtion within lunnale by usiny b i r p e ~ t o r dfins as dcpressors, or they rwred and lmtor bocmrne i~npi~rgtd
against n downfitmm screen. Scvcrd common twhuiquos did nor slimulnra condstenr swimming activity in thwe fish. Our
eutimalew of Ue, for bull I m u provide
~
an undcntmdinp OF their pcrfomcc capacity aod will be useful in modcliug efforts
airnod nt in~provmgfish passage strucrurcs. Wc rccornrnend h a 1 fhhway or culvert designers concarnod with hull trout passtlgc
malntaln vclcciticv within their r h c t u r m ut or below our eatlnmtcs of Ur,,,,
thus talcin&a conservndve approach to ensuring thnt
these flsh cnn itwend migratory obstacles snfely.
lntroductlon
The ability of bull trout (Salvelinw cor2fluentus)
to successfully pass dams, culverts, and other diversion structures is a concern for fishery managers. Concern is warranted because little information exists on the performunw of bull trout that
may provide insight into thcir ability to pass through
culvcrts or fishways. Sptciflcally, no information
is available on the swimming performance or
cxcrcivc physiology of bull trout, which is prerequisite to addressing questions concerning their
passage at various structures.In addition, bull @ul
prefer low water temperaturos, complex forms of
cover, and low velocity mas (Fraley and Shepard
1989, Riemtln and McIntyre 1993, Goetz 1997,
Dambacher and Jones 1997,h r l e and McKcnzic
200 I). The combintition of these prefcmnces and
the presence of rtxidcnt and fluvial life history
types may influence their performance at fish
passage structures, but this notion has no1 been
studied.
The U.S. Forest Scrvicc (USFS)is currently
developing national protocols [or adequate passage of aquatic organisms through culverts. As
prut of this effort, the USFS has developed an
'Author lu whvm cuneqwndcnce should
a nail: mart-mexaGTusgs.gov
be addrrs~ed.E-
analytical model that evaluates different culvcrt
designs for fish passage. Based on swimming
ability of various North American fish species
(determined praviously in laboratory and tisld
studies), thcir ptential performance in different
culvert types can be estimated using the model.
For spe&s for which there are no swimming
performance data (such as bull trout), this model
cannot be applied or must be applied using data
frurr~a similar species. However, hccnusr. of sptcies and life stagt-speciflc differences that detcrmine the swimming performance of fish. using
data from onc species to predict the capabilitic<
uf another is ill advised (Berry nnd Pirnentel1985,
Mesa and Olson 1993).For this reason, the USFS
is compiling date on the swimming performance
of various sptcits of tkhes, particulwly those listed
as imperiled,threatened, or endangered. Bull trout
in thc westcrn United States arc currently listcd
as threatened under the Endangered Species Act.
For this study, we ucidrcsscd the objective nf
determining the critical swimming speed (Ucrrl)
of juvanilc and adult bull trout at three temperatures. The critical swirnming speed of fish is an
irnprtant measure of their biological and physiological performance bccauw U ( ,is thought to
bc a close mcasurc of he maximum aerobic cnpncity of lish (Hammer 1995). Thus, at spccds
near and above Uc,,
swimming involves increased
Northwest Science, Vol. 78, NO.1, 2004
59
recruitment of white muscle fibers and cncrgetia l l y costly anaerobic pathways for mctaboiism
(Burgctz ct al. 1998).A knowledge of U c , ,indicates water velocities where fish may have diffculty swimming for long periods of time. This
information would be useful, for designing new,
or modifying existing, fish passagt structures that
minimize impncts to bull trout.
We used our estimates of U r ,to assess the
potential of bull trout to pass through fishways,
culverts, or other migratory obstacles in a manner similar to Jones at al. (1974) and Peakc et al.
( I 996, 1997,2000).Estimates of UCr,from these
studies have been used to dctcrrninc flshway or
culvert velocities that would allow passaga of
different species of fish within a ccrtaln period
oftime. For example, Jonm at al. (1974) estimated
the Uc, (derivcd fromUc,tests with 10-min time
intervals) of scvcral species of fish from the
McKenzie River to describe speeds that these fish
could maintain for 10 rnin. Thus. asaurning a 10
min transit time through a culvert with vclocitits
similar to the Ucdl,,,one could calculate the maximum length of culvert that fish could realistically
pass. Peakc t t al. (1997) took this analysis to a
morc refined level by deriving models horn (Ic,,
Ucdd,and Ucril10
tests for various species of Newfoundland salmonids, thus providing more flexibility in determining culvert lengths and velocities that allow adquate passage of fish. Our results
provide not only some basic biologicd information on bull trout.but also preliminary performance
mttrics needed for modeling and establishing
guidelines for their passage through culverts and
other structures.
to the PGE owned and operatcd Round Butte
Hatchery at Pclton Dam. Fish captured by angling were transported every day to the hatchery.
When sufficient numbers of bull trout had been
capturcd, we transported them to the Columbia
River Research Lnboratory (CRRL) using a truck
equipped with an insulated tank and aernted watcr. A fish protector (Pond Polyaqua) was added
to the watu (about 6 ppm) to minimize physiological
stress and &taln
skin condition during transport.
Dissolvtd oxygen levels and temperature were
checked routinely during the 4 hr hip.
Upon arrival, fish were separated into 5-cm
size classes (all lengths rcprted herein are fork
lengths, FL)and held indoors undcr a simulated
ambient photoperiod in circular rmks (0.76 m in
diameter, 0.76 m deep) rectlving wcll water. Separating fish into size classes was necessary to minimize cannibalism, which occurred during some
of our carly holding. Larger. adult fish were held
outside in 1.5-m-diameter tanks. Initially, watcr
temperature in all tanks was the same a s water
during transport, about 9-1 1°C. Thereafter, water temperature was adjusted at a rate of 2"Ud to
wlthin + 1"C of the selected experimental ternperatura. The watcr was heated using single-pass
electric heaters, and packed columns dissipated
cxccss dissolved gases generated by heating. All
flsh were acclimated for at least 2 wk to the cxperimental temperature prior to testing. Small fish
(about 10 cm) were fad two earthworms or several salmon eggs (obtained from a local hatchcry) two to three times each week Larger fish
were fed one to two live fish (sub-yearling hatchery salrnonids) two to three times each week.
Selected characteristics of our well water were
meaaured hourly wit11 an automated meter.
Test Fish
Critical Swimming Speed Tests
Juvenile bull trout wcrc collected from a screw
trap on the Mctolius Mvcr, Oregon, from 28 March
to 2 May 2002 by personnel from the USGS
Western Fisheries Rasearch Center and the Portland General Electric Company (PGE) during their
ongoing fish trapping opmtions. In August 2002,
PGE personnel collected adult bull trout by angling in the Matolius River arm of Lake Billy
Chinook. This lake wafi formed by Pelton Dam,
a project that impounds the Crooked, Deschutes,
and Metolius rivers in central Oregon. Fish from
the screw imp were held initially in floating cages
within the river and transferred, once per week,
Critical swimming speed tests on bull &out were
conducted from carly May to late September 2002
at 6",1 lo, and 15°C. These temperatures reprcsent a range of water temperatures naturally encountered by bull trout in the wild (Ratliff 1992.
Buchanan and Gregory 1997). Swimming tests
were conducted in 7..SS, or 84 L Blazka-type
respirometers, depending on size of fish. Water
velocities in the respirometers wcrc crcatcd by n
propeller driven by a variable-speed electric motor. We wed lincar regression to describe the relation between motor speed and watcr velocity
(measured with a flow meter inside the tunncl).
,
60
Mesa, Weiland, and Zydlewski
The resulting regreasion equations were used to
at 1 BUS and the fish was required to swim for
30 min. Thcrcaftcr, the velocity wns increased by
10 cm/s cvtry 30 min until the fish fatigued. Patigue was confirmed when a fish stopped swimming and fell back on a downstream w e n within
the tunnel three times. Rapid changes in water
velocity (i.a., quickly mrning the motor off and
on) were w d to encouragefish to leave the downstream screen.Following tl test, fish wert removed,
lightly anesthetized with bufferedMS-222, tagged
with a small passive integrated transponder (PIT)
tag to facilitate individual idcnt&cation, and pla&
in a holding tank for hture testing.
Critical swimming sped was calculated in B U
s and absolute speed (cmls) using the formula
described by Btamish (1978). None of our fish
had a girth that exceeded 10% of the cross sectional area of a swim tunnel, thm we did no1 correct swim speed estimates for solid blocking. To
assess the influence of fish length on swim performance, we plotted
against fish length at
each water temperature. ithln each tcmpcraturc,
we calculated moan values for Uc,using pooled
data from similar sized individuaL.
calculate tht motor speed necessary for each
respiromcter to achieve a desired velocity. All
relations between motor speed and water vclocity had 9 values ;,0.95.
Ona or two days before a U C ,
test, a fish was
n c t d from a holding tank and t r a n s f e d to an
isolation container. Fish < 30 crn were placed in
a 50.8-cm-long, 26.7-cm-wide, 3 1.7-cm-deep
aquarium and-largerfish were placed in a 0.76m-diameter. 0.76-m-deep circular ttmk.Fish showing signs of diseme, injury. or other abnomalities were not tested. Food was withheld from
isolated fish to cnsurc a post-ubsorptive state
(Btamish 1964. Bernatchez and Dodson 1985).
On the morning of a test, a respirometerwas filled
with water of the appropriate temperature. A fish
was netted from an isoltltion aquarium or tank,
lightly ancsthctizcd by placing i t in a 19-L bucket
containing 50 mg/L of buffered tricaine (MS-222),
rapidly weighed and measured, and placcd into
thb respirometer. The fish wau allowed to adjust
for 2 hr at a water velocity of abwt 1.0 body length/
s @Us).
Following adjusment at 1.0BUS.we subjectd
fish to a brief practice swim test. Based on prcliminary work, we noted that fish performed somewhat better in the swim tunnels if thcy had prior
exparionce with UFri,procedures. For this practice swim, water velocity was increased by 10
cm/s m d the fish was required to swim for a maximum of 2 min (normally 30 min in our standard
Ucr,protocol). The water velocity was then increased by 10 cmls every 2 min until the fish
stopped swimming. The velocity was returned to
1.O BUSand the fish was allowed to recover for
3 hr, after which we fitarted the actual U c ,
tcgt.
For our tests, wo modified the ramped Uc, protocol described by Jain et al. (1997). Water velocity was increased to 20 cm/s nbove the velocity
I'
Collection and Holding
In total, 160 bull trout were collected from thc
Metolius River and Lake Billy Chinook (Table
I). All bull trout survived the stress associated
with capture, handling, and transportation and
arrived in good condidoh at our laboratory. Within
a couple days, bull tmut were feeding aggrtssivcly.
Our feeding regime was successful in producing
growth in many fish. We memurcd 29 PIT-tagged
individuals from mid-May to early August and
again in early November. On average, fish gained
69 g in weight (range 0-246 g) and 4 cm in length
(range 0.2-7,3cm).
Little is known about the long-term maintenancc of wild bull trout in laborntory facilities
-
TABLE 1. Bull trout collection dam#, sirea, melhodr, s h r , and total number offish collected during 2002.
Data
Site
Method
5
19 Apt
3 May
5 Jun
31 Jul
Mctoliuv Rivcr
Metoliu~Rivcr
Metolius Rivcr
Lnka Billy Chinwk
Matolius Rivcr
h k e Billy Chlnook
Screw Lrnp
16 Aug
Screw
unp
Screw Imp
Angling
Fykc net
Angling
< 20
220
Tota1
collcctad
45
55
O
43
0
35
27
0
1
27
0
0
0
1
31
I
1
31
Swimling Performance of Bull Trout
61
and we enc~unteredtwo general problem. F h t ,
early in the study we observed cannibalism and
agonistic behavior that was stressful to subordinntt flsh and led to a few mortalities. To rninimize the effects of these behaviors, we separated
fish into 5-cm size Intervals, held similar sized
fish together, and placed several 15 to 30-cm-long
pieces of PVC pipe (5,7.5, und 10-cm-diameter)
in each tank to provide cover. Second, several fish
~
showed signs of disease or iiury during t h study
(e.g., overtly lethargic behavior, unusually dark
coloration. damaged snouts, frayed fins, cloudy
eyes, e x t d pustules or sores, or bleeding). Them
fish were euthanized and given a corr~pletebacterial, viral, and parasitic screening by personnel
from the USFWS h w e r Columbia River Fish
Health Center.
We attempted to swim 5 ash tit 692,46 fish at
11"C, and 20 fish at 15°C. Of these 7 1 fish, 16 of
them sudessfully completed a Uc,,test; no t a t s
were succw,sful at 6 T .Swim speed was signiticantly influenced by fish lcngth and, because there
were no significant differences in s l o p s or elevations between lints flt for each temperature,
the data warn dcscribcd by single regression lines
(Figure 1). Estimates of U r ,in BUSfor large
fish were lower than those of smaller fish, but
when expressed in absolute speeds, swimmir~g
s p e d was positively related to fish size (Figure
1). Water temperalure had a minor, but significant, influence on mean swim s p a d as evidenced
by fish 11-19 cm at I 1 "C having a lower Ucr,,
than those swum a1 15°C (Table 2; P < 0.05)
The behavior of bull trout in the enclosed swim
tunnels was problematic: only 22.5% of our fish
cornpltttd the Uc,,test. We defined a test as successful If the fish showed steady swimming with
minimal erratic behavior and provided the data
needed to calculate a valid estimate of Uo,.Specifically, fish had to swim for 30 rnin for two velocity steps above the initial adjustment velocity
TABLE 2 . Menu (SE)fork length mid cstimatcv of
Flgurc 1. Linear rcgmssiosu of U, (top p d = BUS; k t tom panel = cmk)as a function of length for ckvcn
fish nwam at ll°C (blmk circlar) and flvc fish at
1YC (open circles).
(i.t.. 1 Bus). All 16 of the succassful fish did
this, and some also swam during a third or fourth
velocity incmment. The behavior of bull trout
resulting in a failed UFd,test typically consi~ted
of flsh flarine out thou pectoral fins and maintaining psition on the hottorn of the tunnel or
rating against the downstream screen instcad of
swimming.As velocity was incmad, fish showing
this type of behavior would usually maintain position on the bottom of the tunnel untU the velocity was too high, at which point they began to
behave erratically and soon became impinged on
the back scrtxn.
U<,,for thrse p u p a o f bull trout at two tcmpcrnture8.
-- -
Sixa rangc
(an)
Ternpcruturr (T)
11-19
11
1I
15
32-42
14-23
..
42
Sample
slzc
Mean lcngth
5
14.8 (1.5)
6
36.2 (1.5)
5
19.3 (1.5)
-
Mesa, Weilimd, und Zydlcwski
(cm)
Uc, (cmlh)
48.24 (h,10)
73.Y9 (1.67)
54.66 (2.35)
urn,,
(Bun)
3.22 (0.20)
2.05 (0.06)
2.89 (017)
Our estimates of Urn,for wild bull trout represent the first laboratory-based swimming performance metrics for these fish and a good first step
toward understanding thcir capacity for exercise
and ability to negotiate fish passage structures.
The critical swimming ~paedsof wild bull trout
compare favorably with those from rainbow trout
(Oncorhynchus mykiss). but only for fish of about
30 cm or greater (Wabb 197I, Pearson and Skvens
199 1, lain et al. 1997. Burgetz et al. 1998). Because of the different protocols used to esthnate
Ur,,
and the numerous factors that can influence
the swimming performance of fishm, it is difflcult to compare etimatw of U, between or within
species. Indeed, we were unable to flnd many
results from other studies on salmonids that we
could validly compare to the swimming performance of our 12-20 cm fish. Brook trout (S.
fontinalis) of about 11-12 cm hnd UCdrestimates
from 4.63 to 4.86 B u s at lS°C (Petersen 1974),
which is much higherthanour estimates for smaller
bull trout. Also, the Urn,
of sockeye salmon (0.
nerka) 9-16 cm in length was 3.3-4.4 BUS at 1@
15OC (Brett and Glass 1973), whichis also higher
than our estimates for smaller bull trout. Critical
swimming speed is influenced by the velocity
increments and the time between increments used
in a study (we Hammer 1995 for a review). Further, the swimming ptrformance of fish depends
on numerous other factors. including species, life
history type, tcmpcmture, body size, fish training, and metabolic condition. For example, diffcrences in stamina bttwcen coho salmon (0.
kisutch) from different streams had a genetic bnAlso, anadromous
sis (Taylor and McPhail B85).
sockeye salmon had a greater mean Ucq,than nonmadromous forms raised under idenhcal conditions (Taylor and Foote 1991). As alluded to by
Hammer (1995), a standardization of protocols
for critical swimming spxd tests, md more understnnding of the factors that influencethese tests,
would facilitatecomparisons between species and
help make Ucn,a morc cornplctc measure of fish
performance.
The poor ptrformancc we observed in mmy
of our bull trout may be in part due to constraints
of the swim tunnels and certain aspects of thcir
life history. The wild bull trout we used in our
study may have found the tunnels too confining,
perhaps eliciting n l x h v i o d stress rcaction leading
to poorperfomance.Juven.de bull trout are closely
nssocinted with stream substrates and extensive
in-stream cover, and prefer low velocity areas
(Fraley and Shepard 1989, Goetz 1997,Dtunbachcr
and Jones 1997, Earle and McKcnzic 2001). This
cryptic, relatively inactive, life style of bull trout
may make them less inched to perform Pdtquately
in confined tunnole under a forced swimming regime, at least relative to other salmouids. On the
other hand, bull trout migrate long difitancasfor
spawning and rewing (Fraley and Shepard 1989,
Swanberg 1997, Burrows et al. 2001), indicating
that their capacity for swimming can be substantial. Further research will be n c c c s s q to elucidate the factors that may influence the performance
of bull trout in lnboratory experiments and provide a morc complete understanding of bull trout
swimming p e r f o m c e .
Fish managers and engineers can use our data
for modeling and establishing guideline6 for the
passtige of bull trout through culverts and other
struc~lfwi.Using our Uk,model
(Figure 1) would
yield conscrvntive estlmales of water velocities
in culverts of different lengths that bull trout could
pass. Such an analyds, based on that of Peakc et
al. (2000), is shown in Figure 2. For example, at
ll-l5'C, a 25 cm bull trout could pass a 60 m
Plgure 2. Maximum water velocitieq thnt will allow bull trout
u l throe nizcr to pnaa culvorta of vnrious lengths in
11" 10 15'C water. The lines were datcmined 88
follows: maximum water velocity within a culvcrt
equal8 the highest sp%d n fllih can malntaln for 30
lnin (U& minu* thc minlmunl ground sped required to pass Ihe culvert In 30 mln (culvert Icnglh/
1,800 9). The U<, vnlucs were cslculntcd by nubstiwting length valuca inlo tho upprophate cquntion from Figure I .
Swimming Performance of Bull Trout
63
Acknowledgements
culvert If water velocities were kept below 57
c d s . Taking the most conservative approach, the
models in Figure 2 would predict that hull trout
from 15 to 40 cm Fi'L, could pms culverts up to
100 m in length provided water velocities w e n
below 42 c d s at 11-1 5 T .Further research would
be needad to include the influence of different
water temperatures, fish sizes, and swim speeds
on our models of bull bout pusage through culverts.
We believe our estimates of Uc, for bull trout
represent an important benchmarl towards understanding their capacity for exercise. As such.
theat estimates should serve as a good starting
point for efforts a i m d at designing or improving
passage structures for bull trout. Until more information becomes available. we recommend that
fishway or culvert dcaigners concamcd with bull
trout paesage work to maintain velocities within
their smcturm at or below our estimates of U+,
thus taking a conservative approach to ensuring
that these fish can ascend migratory obstacles
safely.
We thank Chris Allen, Jarvis Gust, and Kathlccn
Moynan of the U.S. Fish and Wildlife Service
for their assistanca in obtaining ESA permits and
administmtion; Scott Lewis and personnel from
Portland Oeneral Electric for their constant willingness to help and their expcrtisc in the field;
Mike Hayts and personnel from the USGS Watem
Fisheries Research Center for kindly collecthg
fish from the screw trap; Chris Brun and Patty
O'Toale of the Warm Springs Mbt, Mlke Kiehle
of the U.S.Forest Service, and Steve Mam of the
Oregon Department of Fish and Wildlife for advice on obtaining bull trout; Susan Gutenkrger,
Ken Lujan, and Mary Peters of the Lower Columbitl Fish Health Center for their fish health
screenings;l 3 d y Allen, Amy Arbeit, Susie Irnholt,
Ian Jezorek, Bccky Reiche, Bdan Sharp. and Joe
Warren of the CRRL for angling, field, and laboratory assistance; and Kim Clarkin of the USFS
for providing funding and admtnistrativt guidance.Comments by Steve P a and Don Stevens
improved the manuscript.
Beamis4 F. W. H. 1964. Respiration of fimhcm with apecial
emphasis on standard oxyeen consumption. ll.Influonoo of wclghl nnd lcmpcraturc on retipiration of savera1 spccica. CBnadianJournal of Zoology 421 77-188.
Bcamiuh. F. W.H. 1978.Swimming cnpacity. Pages 101-175
In W. S. Hoar and D. I. Randall (editors), Pirh Physiology, volume V U Academic Prtns. New York
Btmatchez, L.. and J. J. Dodson. 1985. Influence oE tcmpxaturc and cutrent a@ on the swimming capncity
of lake whitaflsh and cim. Canadian Journal of Fishadcr and Aquatic Sclencc~42: 1522.1529.
Bcmy, C.R.,Jr., and R. Plmenkl. 1985. Swimminu performances of three ram Colorado River finhas. Tranaactiom of the American Fi~hariesSociety 114397402.
Bmtt. I. R.,and N. B.Olraa. 1973. Matabollc r a w and crilicrl uwlmming speeds of fiockeyc salmon
(Oncorhynchu n r h ) in mktion lo fatlguc timc and
tcmpcratura. Journal of the Flshcdes Rasanrch Board
of Canada 30:379-387.
Buchanan, D. V.,and S. V. '3ragory. 1997. h c l o p m e n l of
w a r temperature standards to protect and rcstorc
habltnt for bull trout and other cold water rpcciafi in
Oregon. Pagee 119-126 I n W.C. Mrclrey. M . K.
Brcwln. and M. Monira (editors), Frienb of the Bull
l h u t Confarcncc Procccdinps,Bull Trout Tsrk Force
(Alberta).Trout Unlimitcd Canads. Calgary.
B u m I. J., A. Rojw-Varg~,S. 0.Hinch, md D. J. Randall.
1998.Initial recruitment of anmmblc metabolism
during aub-mnximal swin~niingIn rainbow trout
(Oncorhynchus mykiss). Journal of Expcrimsn~slBiology 201:2711-2721.
Burrows. J.. T.Euchnar, and N. Briocanto. 2001. Bull trout
movement pattern: IIalfwny Rivet and Peace Rlvw
p r o m s . P a p 153.158 In M. K. Braw1n.A. J, Paul,
and M.Monlta (adltors). Bull Trout U C o n f c r ~ c c
Roceadings, Trout Unlimitcd Cmada C . l g q .
Dambachar, J. hi.,and K. Jones. 1997, S t n u n hnblult of juvcnilo bull trout populadom in Omgon and bcnchmarks for habitat qudlty. Pngc~353-360 In W.C.
Mackay. M. K. Bmwin, and M. Monha (editors),
Friands of the Bull Trout Conf-Rocoedings.
Bull
Trout W Farce (Alhta). Trout Unlimlwd Canada.
Calepry.
Earle, J. E., and J. S. McKEnzic. 2001. Microhabitat uae by
juvonilc bull unut in mountain streams in the Copton
Crosk system. Albana, and its relation to mining ACllvity. Page# 121-128hM. K. Bmwin-h. J. Paul.md
M. Monita (editors), Bull Trout I1 Conference I'r*
c d i n g s . h u t Unlitnitad Catma Calgary.
Fralcy. J. J.. and B. B. Shepard. 1989. Lifa history', ecology
and population ~ t s hof
s migratory buU trout (Sdvelinru
corlflusnhrs) in the Flathod L& and R l v ayatcm,
~
Montana. Northweat Science 63133-143.
WK,F. A. 1997. Habltat use of Juvcnile bull Uout in Cascad. mountdn streams of Oregon and Wmhington.
P a p 339-352 h W. C. Mackay, M. K. Bmwin, and
M. Monlta (cditorn), Fricnda of the Bull Trwl Confercncc Proccadingo. Bull T m t k k Porn (hlbctta),
Trout Unlimited Canada. Cnlgnry.
Hammer, C. 1995.Fatiguc and exerclw testa wlth fish,Com'
parative Blochammlry und Phyaiolopy 1l2A:l-20.
lain, K. E., I. C. Hamilton m d A. P. ParrcU. 1997. U ~ of
Ca
rnmp velocity t c ~tto rn0MUra crltlcal swimming.spaed
64
Mesa. Weiland, and Zydlewski
in rainbow trout (Oncorhynchur mykiss). Comparative BlochamiMq and Physiology 117A:441-444.
Jonu. D. R., J. W.Kiceniuk, and 0.S. Bunford. 1974.Evalundon of the swimming pcrformance of savsml t h h
species from the McKsnzle River. Journal of tha Fhhc r i a Research B o d of Canada 31: 1641-1647.
M a ~ aM. G..and T. M. Olaon. 1993. Prolonged swirnrninp
prformnncs of wrtharn aqunwfish. h s a c t i o n ~of
tho h r i c a n Fisheries Sadsty 1U:l lWl110.
Rake. S.. F.W.H.Bcamish. R. S. McKinley, D.A. Strum
and C. KatopPdis. 1996. Relntlng rwlmmlng parformancc of& nhrgton, A~lpcnstr&hV~~tnS.
to fishway hip.Canadian Journal of Fishdmand Aquhc
Scieacaa fi1361-1366.
Peakc. S.. R. S. McKinley, nnd D. A. Scruton. 1997. Swirnnung pdortnanca of various Pm6hwntar Nswfoundland aalmonida reletivm to habitat wlectlon and Bshwly d c n l ~Journal
.
of Fish Bblogy 51:71&723.
PC*, 3.. R. S. McKinley, and D. A. Scruurn. ZOW. Swimmlng parfonnnnce of wallaya (Stbstedlon vitnum).
C d m Joumd of Zaoloyy 78:1686-1690.
Pcarson. M.P.. and E. D. Stcvcns. 1991. Splonoctomy Imp l m aerobic swim p r f o n n c c in tmur Canndlrn
Journal of Zoology 69:2089-2092.
Petenen. R H. 1974. Influence of Fcniirothion on swimming
velodtlo~Of brook wut (Salvelinusf o h h ) , Jourd o f tImF&uriasRasearch Board of Canada3l:l7Y/1762.
Ratliff, D. E. 1992. Bull trout investigalions in tha Maroliun
River-Lake Billy Chlnmk system. P q e 3~7 4 4 In P.
J. Howdl md D. V. Buchannn (editom). PKlcotdlngs
of the G m h m Mountah Bull Trout Workrhop, Oregon Chnptcr 01 the American Flrheriam Soclcty,
Corvnllin, Oragon.
Riaman, 6. E., and J. D. McIntyre. 1993, Damopphic und
habitat quircrncnts for con~rvatlonof bull trout.
General Tcchnlcal Repon 1NT-302, Unlted Stater
Pcrut Sarvlcs. Intermwntalo R c m h Stntion,Boim.
Idnho.
SwanbMg. T.R. 1997. Movements of and habitat UM by fluvial bull mt in h e Blackfm River, Montana. 'lhnasotiom of the American Fisheries Society 126:735746.
Taylor, E. 8..and I. D.McPhail. 1985. Variation In bunt nnd
pmlongod awimmlng performance among British
Columbia populltlo~lliof coho tialmon, Oncorhynchw
lcinrtch. C a n d a n Journal of Fhhsrisr m d Aquatic
Sclencas 42:2029-2933.
Taylor, E.B., and C. J. Fwk. 1991. Critical swimming,vlb
locities of juvcnilo =kcye salmon and kokancc, dw
madrornouu and non-anadromous formn of
O n c o r h ~ h u ns r r h (Wdbnum). Journal of Fish B1ology 38:407419.
Webb, P.W. 1971. The swimming anargatioa of trout. II.Oxygcn consumption and swimming officlcncy. Journal
of Experimental Biology 55:521-540.
Received 28 April 2003
Accepted for publication 22 September 2003
Swimming Performance of Bull Trout
65