Within-Season Homing Movements of Displaced Mature Sunapee ...

The University of Maine School of Marine Sciences

DigitalCommons@UMaine

Marine Sciences Faculty Scholarship

1-1-1977

Within-Season Homing Movements of Displaced
Mature Sunapee Trout (Salvelinus Alpinus) in
Floods Pond, Maine

James McCleave

University of Maine - Main, [email protected]

G. W. Labar

F. W. Kircheis

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Repository Citation

McCleave, James; Labar, G. W.; and Kircheis, F. W., "Within-Season Homing Movements of Displaced Mature Sunapee Trout
(Salvelinus Alpinus) in Floods Pond, Maine" (1977). Marine Sciences Faculty Scholarship. Paper 144.
http://digitalcommons.library.umaine.edu/sms_facpub/144

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Downloaded by [University of Maine] at 11:08 22 December 2011 Within-SeasonHomingMovementsof DisplacedMature Sunapee
Trout (Salvelinus alpinus) in Floods Pond, Maine

JAMES D. MCCLEAVE AND GEORGE W. LABAR•

MigratoryFish ResearchInstituteandDepartmento/Zoology
Universityo! Maine, Orono,Maine 04473

FREDERICK W. K•RCUEIS

Maine Departmento] Inland Fisheriesand WildIi/e
Bangor, Maine 04401

ABSTRACT

Tagging,displacemenat nd recapture,and ultrasonictracking of displacedmature Sunapee
trout (SalvelinusaIpinus) in Floods Pond, Maine, demonstratedthat rapid within-season
homingoccursin this relict form of Arctic char. Of the trout displacedabout1.8 km from their
spawninggroundfrom 1972 to 1975, 9% to 32% were recaptured one to four times within the
samespawningseasonin trap nets set on the spawningground. Eight of 14 trout tracked
ultrasonicallyin 1975hornedin 2.5 to 10.0h. Movementsof the homingfish were variable; some
trout hornedparallelingthe shoreline,othershornedin open water or used a combination
of near-shoreand open-watermovements.Behaviorwas similar betweenthe sexesand during
day and night, althoughtwo fish did beginto movejust at sundown.Swimmingspeedsranged
from 15 to 35 cm s-• and averagedabout0.6 bodylengthss-•. Swimmingd'irectionswerenot
influencedby wind and wave direction, nor were swimming speedswithin individual tracks
influencedby cloud cover, wave height, or water depth. Heavy overcastat night m&y have

inhibited movement.

Sunapeetrout are apparently familiar with the entire lake and travel widely within it.
Visual features are postulated as orientational cues, though use of such cues is not clearly
demonstratedby our experiments.

The Sunapee trout is a land-locked post- areas of the lake with similar substrata are not

glacial relict of anadromous arctic char utilized.

(Backus1957; Everhartand Waters1965), In conjunction with spawn-taking opera-

givensubspecificstatus,alongwith the Quebec tions and tagging for other life history studies

red trout and the bluebacktrout, asSalvelinus (Kircheis 1976), it was noted that many

alpinus oquassaby Qadri (1974). Only ripenlug, ripe, or even artificially stripped

Floods Pond, Hancock County, Maine sup- fish displaced 1.8 km from the spawning

ports a native, reproducing population of ground returned to the spawning ground

Sunapeetrout. The Sunapeetrout wasrecently within a short time and also used the area in

introducedinto sevenother Maine lakesby the subsequentyears. This observationled to tag

Maine Department of Inland Fisheries and and recapture studies to be reported here to

Wildlife in an effort to expand its distribution determine if the fish home and also to the

and insure its survival. primary purposeof the presentstudy which

Studiesof the reproductivebiology of Suna- was to determine by ultrasonic telemetry the

pee trout have been undertaken (Kircheis detailedwithin-seasonhoming movementsof
1976) to help understandwhy introductions displacedmature Sunapeetrout. Specifically
into other lakeshave not yet establishedrepro- we wished to determine 1) pattern(s) of
movement,if any; 2) swimming speeds;and
ducing populations.In FloodsPond Sunapee 3) whether homing occurredboth day and

trout spawn at night during October and night.
Noverhber in a restricted shoal area of 10-100
Hominghas beenreportedfor severalspe-
cm rubble off a point of land exposedto wave ciesof chars,e.g.by Frost (1963) for a land-
action from nearly every direction. Other lockedsubspecieosf arctic char, Salvelinus

alpinus willughbii, by O'Connor and Power

•Present address: School of Natural Resources,

University of Vermont, Burlington, Vermont 54301. (1973) for brooktrout (S. [ontinalis),by

156

McCLEAVE ET AL.--TROUT HOMING 157

Downloaded by [University of Maine] at 11:08 22 December 2011

F•½uaE1.--Ultrasonictracksof/ive Sunapeetrout in FloodsPond/oilowing displacement/romtheir spawn-
ing ground. Opencircle is releasepoint, arrow indicatesspawningground.

Armstrong (1974) for Dolly Varden (S. METHODS
malma), and by Martin (1960) and Rahrer
(1968) for lake trout (S. namaycush);how- Study •4rea
ever, such behavior is not nearly as well
studiedas in the generaSalmo and Oncorhyn- FloodsPond is an oligotrophiclake located
in a hilly wooded area of the Union River
chl•$. drainage in south-centralMaine. The lake is

158 TRANS. AM. FISH. SOC., VOL. 106, NO. 2, 1977

265 hectaresin area (Fig. 1) with a maximum on the starboard side and suspended 0.5 m

depth of 45 m and a mean depth of 12.5 m. belowthe water surface(McCleaveand Hor-

Tag and recapture studies were conducted rail 1970). Ultrasonic transmitters were

from mid-October to the end of November, pulsed type, usually 55-60 kHz, but one 120

1972-1975. Ultrasonic tracking was done be- kHz and one 230 kHz transmitter were used.

tween 15 October and 9 November 1975. All were 8-10 mm diam. X 32-36 mm long.

All but one of the 14 tracks began at the

Tagging-Recapture live car 125-250 m offshore at the NW end of

Sunapeetrout were capturedon the spawn- the lake about 1.6 km from the spawning
ing ground in two trap nets,which were usu- ground (Fig. 1); one beganat the shoreline
ally tended in the morning. The fish were at the NW end. After a fish was released the
transportedin coveredtubs to the NW end boat alternately waited and movedtoward the
of the lake for examination. They were then fish on bearings obtained from the hydro-
lightly anesthetizedin an approximately 1:9, phone. We moved closeto the fish to make a
Downloaded by [University of Maine] at 11:08 22 December 2011 500 MS222 solution,and total length,weight, position plot each 15 min.
sex,degreeof maturity,fin-clipor tagnumber, Most positionplotsweremadeby measuring
the two adjacent horizontal angles between
if any, wererecorded.
Fish for conventionatlaggingweremarked three landmarks with a sextant. Some near-
with jaw tags and a temporary clip of the shore plots were made by observing land-
uppertip of the caudalfin to indicatethe fish marks on an aerial photograph. At each
had been processedduring the current season. position, we measured wind direction and

Many of the mature fish were then stripped velocity, wave direction and water depth.
and released or were held in live cars up to a Cloud cover and wave height were estimated.

few daysprior to strippingand release.Im- Data Analysis
mature or unripe fish were releasedimmedi-

ately. Fish werereleasedat the shorelinejust Tracks were plotted on a 1:7,900 work

NW of the ultrasonic tracking release point map. A three-arm protractor was usedto plot

(Fig. 1). sextantsightingsand field notesto plot other

Sincethe trapswerenot necessarilychecked positions. Basedon straight lines betweensuc-

eachday,andtheydid notcatchall fishonthe cessivepoints, swimming azimuths,distances,

spawningground,andtheymostlycaughtfish speedsand straightnessindices (Stasko et al.

at night, homing times based upon times of 1973) were determined. Swimming azimuths

recapture are overestimatedand thus not pre- were expressedrelative to wind direction and

sented. Rayleigh'stest (Batschelet1965) usedto de-

Ultrasonic Tracking termine if there was significant clustering for
each track. Wave direction measurements were

Fish for ultrasonictracking were captured not utilized, since wind and wave direction
and processedsimilarly to fish for conven- usually coincided, and wind directions were
tional tagging. Mature, unstrippedfish were more accurately measured. Correlation coef-

jaw-tagged (if untagged) and the transmit- ficients between swimming speed and cloud

ter was pusheddownthe esophagusinto the cover,waveheight, and water depthwere cal-

stomachwith a glassrod. Caudal clips were culated for each track.

applied in only a few cases. Transmitter-

ta.ggefdishwereusuallpylacedin a livecar RESULTS

at the releasesite for at least 1 h and up to 24 Tagging-Recapture

h for recoveryfrom anestheticbeforetraek- In the years1972 through 1975, 9% to 32%
ing; onewasreleasedimmediatelyF. ishin the of the displacedSunapeetrout wererecaptured
on the spawning ground at least once within
live car had accessto the water surface.

The tracking systemconsistedof a receiver

installed in a 5 m outboard runabout. A 360 ø the samespawningseason(Table 1). Three

rotatabledirectionalhydrophonewasmounted percent were recaptured two to four times

McCLEAVE ET AL.---TROUT HOMING 159

within the season. Homing percentages are TABLE1.--Recaptureswithin the spawningseasonon
the spawninggroundoJSunapeetrout taggedand
underestimateds, incethe traps did not catch displacedabout1.8 km [rom the spawningground.

all fish on the spawning ground. However,

these data establish that substantial within- Number homing fish
recaptured
seasonhoming occurs, often within 24 h.
Yearly comparisonsare not warranted, since Year Number More than

Sex displaceel Total once

trapping effort was not the same all years. 1972 c? 80 6
Greatesteffort wasin 1975, and the percentage • 173 17 Not
recaptured was greatest that year. Consis- Immature
tently, slightly more femalesthan maleswere 6 0 recorded
recapturedeach of the 4 yr, but the overall 1973 Total
differencewasnot significant (X•-- 5.1, 3 dr, 259 23
d•
P > 0.05). • 153 26 1
Immature 165 41 8

Total 11 00

329 67 9

1974 d 71 7 1
0
Downloaded by [University of Maine] at 11:08 22 December 2011 Ultrasonic Tracking • 79 14
1
Total 150 21

Fourteen Sunapeetrout were tracked•, and 1975 d 178 53 7

eight of thesewere trackedback to the spawn- • 85 31 12

Immature 1 0 0

ing ground. Homing time rangedfrom 2 h Total 264 84 19

25 min to 10 h, and swimmingdistancefrom

2.8 to 8.4 km (Table 2). One trout was

tracked home twice (nos. 1 and 3) and an- le.g. nos. 3 and 10, Fig. lB) wanderedcon-
other tracked nearly home a second time siderably onto and off the actual spawning

(nos.2 and 6). shoal.

Movements of the trout varied from indi- The remainingfour trout (nos.5, 7, 9, and

vidual to individual, but widely ranging move- 12) wandered extensively near shore or in

ments were typical even among homing trout. openwater or bothduring the trackingperiod.
Three trout (nos. 1, 10 and 13, Fig. 1A,D) One of these (no. 5, Fig. 1A) entered the
were tracked home along the westerly shore- cove at the NW end of the lake and remained

line. These trout travelled around the SW arm there. Only oneothertrout (no. 13, Fig. 1D)
rather thancrossingit directlyto thespawning entered that cove.

area. Trout on track nos.2, 3 (Fig. lB) and All patterns of behavior mentioned above

11, hornedby travellingalmostthe entire dis- were observed during both day and night.
tancein deep,openwater, thoughnos.3 and However,on two occasions(nos. 13 and 14,
11 moved approximatelyparallel to the west- Fig. 1D) sunsetseemedto trigger movement.

erly shoreline.Troutnos.8 (Fig. 1C) and14 Both trout had wanderedfor 4 to 5 h during
horned using a combination of along-shore afternoon, but within a few minutes of sun-
and open-watermovements;nos. 4 and 6, down began moving rather directly toward

trackednearlyhome,showedthe samecombi- the spawningarea (Fig. 1D). In both cases

nation, plus considerablewandering along swimming speeds increased greatly (about

shoreand in openwater. Trout no. 8 (Fig. 180% and 260%) after nightfall, and in one

1C) exhibitedextensivemovemenat longthe case the straightnessindex increasedsixfold

easterly shore, long, straight movementsin (Table 2). Within other tracks, swimming

open water, and the ability to cruise nearly speeds and straightness indices were incon-

the entire lake in relatively short time. sistentlyvariablefrom day to night (Table 2).

Twice (nos.4 and 8, Fig. 1C) trout swam Mean straightness indices and swimming

right throughthe spawninggroundand sub- speedsas centimetersper second and body
sequentlymadesubstantiaml ovementbsefore lengthsper secondwere not significantlydif-
returning. After arriving initially, sometrout ferent from day to night (t-test; P > 0.05).

Swimmingdirectionwas apparentlynot in-

• Twelve individualswere tracked; track nos.1 and fluenced by wind direction (and therefore
3 were of the sametrout, as were track nos.2 and 6.
probablynot by wavedirection). In 13 tracks

160 TRANS. AM. FISH. SOC., VOL. 106, NO. 2, 1977

TABLE2.--Tracking times, minimumswimmingdistances,minimumswimmingspeeds,and straightnessindices
o! Sunapeetrout during day portions,night portions,and entire tracks. Relativeswimmingspeedsare in
bodylengths (BL) swumper second.H alter the track number indicatestrout tracked home to the spawn-

ing area; R indicatesrecaptured.For most tracks distancesand swimmingspeedswere calculatedonly
on movementportions, not including time be!ore movement began or wandering about the spawning

groundaJter homing.

Day portion

Relative

Track Tracking Total Time Distance Swimming nfing Straight-
number Release time length tracked tracked speed speed ness
date (EST)
1 HR Sex (cm) (h:min) (kin) (cm s •) (BL s-•) index
2 HR,' 15-X-75 1100-1415
3 HR • 17-X-75 1030-1315 • 47.8 2:25 3.05 35 0.7 54
4R 17-X-75 1346-2145
5R 19-X-75 1100-0030 • 38.1 2:45 2.97 30 0.8 27
6 Rc 20-X-75 1900-0200
7 21-X-75 0917-1600 • 47.8 2:00 2.98 42 0.9 54
8 HR 22-X-75 0815-1515
9 22-X-75 1845 0115 d 32.7 4:30 2.78 . 17 0.5 22
10 H 25-X-75 1015-2300'
11 H 2-XI-75 1045-2030 • 32.5
12 R 3-XI-75 1800-2145
13 H 4-XI-75 1213-2230 • 38.1 6:00 5.30 25 0.7 27
14 H 6-XI-75 1130-1930
9-X1-75 1045-1530 d 32.2 7: 00 4.62 18 0.6 24
Mean
Downloaded by [University of Maine] at 11:08 22 December 2011 7:26 d 34.0

d 33.9 4:45 1.82 11 0.3 13

• 34.5 4:45 3.16 19 0.6 53

• 36.3

• 42.3 2:45 2.14 22 0.5 42

d 36.7 4:32 2.77 17 0.5 8

• 38.0' 5:15 2.52 13 0.3 28

37.5 4:15 3.10 23 0.6 32

Night portion

Track Release Tracking Sex Total Time Distance Relative Straight-
number date time length tracked tracked ness
(EST) •) (cm) (h:min) swim- index
1 HR 15-X-75 • (kin)
2 HR a 17-X-75 1100-1415 • 47.8 Sxvimming ming
3 HR • 17-X-75 1030-1315 d 38.1 speed speed
4R 19-X-75 1346-2145 • 47.8
5R 20-X-75 1100 0030 •) 32.7 (cm s-t) (BL s t)
6 R• 21-X-75 1900-0200 d 32.5
7 22-X-75 0917-1600 cf 38.1 1:12 0.78 18 0.4 17
8 HR 22-X-75 0815 1515 d 32.2
9 25-X-75 1845-0115 • 34.0 8:45 6.69 21 0.6 19
10 H 2-X1-75 1015-2300' • 33.9
11 H 3-XI-75 1045-2030 • 34.5 5:30 2.87 15 0.5 12
12 R 4-XI-75 1800-2145 d 36.3
13 H 6-XI-75 1213-2230 • 42.3 0:30 0.48 27 0.7 44
14 H 9-X1-75 1130-1930 36.7
1045-1530 38.0 6:00 7.58 35 1.0 21
Mean
7: 26 37.5 7:15 4.97 19 0.6 13

4:00 2.24 16 0.5 8

2:d5 2.81 28 0.8 53

5:30 2.30 12 0'.3 9

2:43 2.97 30 0.8 48

4:45 5.86 34 0.9 26

4:27 3.60 23 0.6 25

Entire track

Relative

swim-

Tracking Total Time Distance Sxvimming ming Straight-
time
Track Release length tracked tracked speed speed hess
number date (EST)
Sex (cm) (h:min) (kin) (cm s •) (BL s-•) index

i HR 15-X-75 1100-1415 • 47.8 2:25 3.05 35 0.7 54
2 HR:, 17-X-75 1030-1315
3 HR b 17-X-75 1346-2145 • 38.1 2:45 2.97 30 0.8 27

4R 19-X-75 1100-0030 • 47.8 3:12 3.76 33 0.7 45
5R 20-X-75 1900-0200
d 32.7 13: ] 5 9.48 20 0.6 14
6 R• 21-X-75 0917-1600
y 32.5 5:30 2.87 15 0.5 12
7 22-X-75 0815-1515
•) 38.1 6:30' 5.78 25 0.7 22
8 HR 22-X-75 1845-0115
9 25-X-75 1015-2300' d 32.2 7:00 4.62 18 0.6 24
10 H 2-XI-75 1045-2030'
11 H 3-XI-75 1800-2145 o'34.0 6:00 7.58 35 1.0 21

12 R 4-XI-75 1213-2230 d 33.9 12:00 6.79 16 0.5 12

13 H 6-XI-75 1130-1930 y 34.5 8:45 5.40 17 0.5 31

14 H 9-X1-75 1045-1530 y 36.3 2:45 2.81 28 0.8 53

y 42.3 8:15 4.44 15 0.4 22

d 36.7 7:15 5.74 22 0.6 27

• 38.0 10:00' 8.38 23 0.6 19

Mean 7:26 37.5 6:50 5.26 24 0.6 27

Transmitter signal lost by tracking cre;v part of time, acthal homing t/ane = 6:45.
Same trout as track number 1.

Same trout as track number 2.

McCLEAVE ET AL.--TROUT HOMING 161

during which there was wind, the swimming capture nor the time until recapture. Four

directions of only one trout (no. 10) were of the eight were tracked home in 2.5 to 6.0 h,

significantly clustered when plotted relative yet they were recaptured only after 2 to 16

to the wind (direction re wind = 31% vector days. Four other trout tracked home in 2.75

length = 0.3069, P < 0.05). Correlationsof to 10.00 h were not recaptured,though they

swimmingspeedswith amountof cloud cover, were only at large 3 to 10 daysbeforethe trap

waveheight,andwater depthwereinconsistent nets were removed. Two fish that wandered

and highly variable suggestinglittle, if any, extensivelyduring tracking were recaptured

effect of these environmental factors on swim- after 5 and 17 days.

ming speed. Possible influences of cloud cover

and sun or moon visibility upon movement DISCUSSION

Downloaded by [University of Maine] at 11:08 22 December 2011 patterns were difficult to assess. Only one Gerking (1959) usedthe term homing in a
trout was trackedentirely under overcastskies general sense to mean the return of fish "to
at night (no. 5, Fig. 1A) when visual cues a place formerly occupied" following natural
were minimal; it wandered in a restricted cove or artificial displacement. No complex orien-
at the northwest end of the lake. Two other tation mechanism is necessarily implied by
the term homing, but the animal must possess
trout tracked entirely at night under clearer some means of recognizing "home." The
skies with moonlight horned. There was no mechanismsunderlying homing may range
evidenceof cloud influence during the day.
from use of search and landmarks to true bi-
Swimming speedsranged from 15 to 35 cm
s-• and 0.5 to 1.0 bodylengths(BL) s-1, and coordinate navigation (Hasler et al. 1958).
straightnessindicesranged from 12 to 54 for Search may be random or patterned.
entire tracks (Table 2). Speedsand straight-
Since there is but a single spawning area in
ness indices of the four trout classed as wan- Floods Pond, the Sunapeetrout by definition
must exhibit natal homing and repeat homing
derers averaged only about 60% of those of in subsequent spawning seasons. Our data
all other tracks. Although highly variable, demonstratei,n addition, that thesetrout can
averageswimming speedwas significantly re- home quickly within a singlespawningseason.
lated to total length according to the least
squares regression equation: More significant, however, is the observa-

Y = -5.391 + 0.775 X tion that the trout are able to travel extensively
about the lake and still return to the spawning

where Y = swimmingspeedin cm s-•, X = ground relatively quickly. We had hypothe-

total length in cm (P < 0.05 that the regres- sized that the trout would return rather di-

sion coefficient is not different from zero). rectly to the spawningground during the day

When swimmingspeed(Y) is expressedas or after nightfall, or that they would wander

body lengths per secondthe regressionbe- near the releasepoint as, for example, some

comesnon-significant (P > 0.10): displacedcutthroat trout (Salmo clarki) are

Y = 2.200 + 0.003 X; known to do (McCleave and Horrall 1970;
McCleaveand LaBar 1972). The wandering

i.e., on the averagetrout swam 0.6 BL s-• re- behavior might indicate an inability to home
gardlessof fish size. quickly or a disruption of behavior causedby
experimental procedures. Some Sunapee trout
There were no sex differences in movement did home rapidly and directly (nos. 1, 2, 3,
11; Fig. 1A,B), while others wandered near
patterns or in swimming speeds. Both males the releasepoint (nos. 5, 9). The movements
(averagelength= 34 cm) and females(aver- of severalother trout (e.g. nos.4, 8, 14; Fig.
age length = 40 cm) swam at just over 0.6 1C) were extensive,but they did not appear
BL s-t on average. disoriented. These movements suggest the

Eight of the 14 trout tracked (57%) were
recaptured on the spawning ground after be-

ing at large2 to 21 days (mean 11 days), but interpretation that Floods Pond is sufficiently

the pattern of movementduring tracking was small that trout can learn features of the entire

neither indicative of the probability of re- lake. They are able to move widely about the

162 TRANS. AM. FISH. SOC., VOL. 106, NO. 2, 1977

lake, but are capable at any given time of the figure. We appreciate the critical com-
moving quickly onto the spawning ground.
ments on the manuscriptby Messrs.Edward
We have some circumstantial evidence to Gardella and Kendall Warner, and we ac-
knowledge the cooperation of the Bangor
support the interpretation that Sunapee trout
may make daily movementson and off the Water District.
spawning ground. Multiple recaptures sug-
gest that trout spend a considerable time in LITERATURE CITED
the spawningarea, but our observationsshow
Downloaded by [University of Maine] at 11:08 22 December 2011 that the area is devoid of trout during the ARMSTRONGR,. H. 1974. Migration of anadromous
day. We often relocatedpreviously tracked Dolly Varden (Salvelinus malma) in Southeast-
trout with functional transmitters (including ern Alaska. J. Fish. Res. Board Can. 31: 435-
some tracked home) in various parts of the
lake during the day and near the spawning 444.
area at night. If this is a normal behavior,
Sunapee trout must make repeated use of their BAckEr;sR, .H. 1957. The fishes of Labrador. Bull.
homing ability within a singleseason. Track- Am. Mus. Nat. Hist. 113: 279-337.
ing of fish released on the spawning ground
would be instructive in this regard. BATSCHELETE, . 1965. Statistical methods for the
analysis of probleats in animal orientation and
If Sunapeetrout are familiar with features certain biological rhythms. Am. Inst. Biol. Sci.,
of the lake, it is temptingto speculatethat their Wash. 57 pp.
orientation in the lake is based in part upon
EVERHARTW, . H., ANDC. A. WATERS.1965. Life
visual cues above or below the water surface. history of the blueback trout (Arctic char,
Salvelinus alp•nus Linnaeus) in Maine. Trans.
For example, five trout exhibited movements
essentiallyparalleling the western shoreline, Ant. Fish. Soc. 94: 393-397.
but sometimessubstantiallyoffshore (see Fig.
1A,B,D). The westernshore is a high, steep FROSTW, .E. 1963. The homingof charrSalvelinus
bluff covered with dark trees. To an above- willughbii (Glinther) in Windermere. Anim.

water observer,it makesa prominentvisual Behar. 11: 74•32.
contrast with the sky, particularly in the
afternoon when most tracking occurred. It is GERICtNC,S. D. 1959. The restricted movement of
also prominent on clear nights. Two trout fish populations. Biol. Rev. 34: 221-242.
tracked at night under full moon were fol-
lowed in part alongthe easternshoreline,also HASLERA,.D., R. M. HORaAL[W, . J. W•sBY,ANDW.
a high bluff over which the moon rose (see BRAEMER1.958. Sun-orientatioanndhomingin
Fig. 1C). Underwaterfeatures,suchashuge fishes. Limnol. Oceanogr.3: 353-361.
boulders and gravel bars, are prominent and
easily recognizableto divers. While they pos- KmCHE•SF,. W. 1976. Reproductivebiologyand
sibly contribute to orientation, they alone earlylife historyof the Sunapeetrout of Floods
cannot account for long straight movements Pond, Maine. Trans. Ant. Fish. Soc. 105: 615-
observed in open water.
619.
ACKNOWLEDGMENTS
MARTellN, .V. 1960. Homingbehaviourin spawn-
We thank K. A. Turgeon for assistancein
the field, in analysis,and in preparation of ing lake trout. Can. Fish Cult. 26: 3-6.

McCLEAVEJ,. D., ANDR. M. HORRALL.1970. Ultra-
sonictracking of homing cutthroat trout (Salmo
clarki) in Yellowstone Lake. J. Fish. Res. Board

Can. 27: 715-730.

---, a•) G. W. LABAa. 1972. Further ultrasonic
trackingand taggingstudiesof homingcuttin'oat
trout (Salmo clarki) in Yellowstone Lake. Trans.
Ant. Fish. Soc. 101: 4z1•54.

O'CoNnORJ,. F., ANDG. POWEa. 1973. Homingof
brook trout (Salvelinus]ontinalis) in Matamek
Lake, Quebec. J. Fish. Res. Board Can. 30:

1012-1014.

QA•)RI, S. U. 1974. Taxonomic status of the Salve-

linus alpinuscomplex. J. Fish. Res. Board Can.

31: 1355-1361.

RA}•RE•, J.F. 1968. Movements of adult lake trout

in Lake Superior. Trans. Ant. Fish. Soc. 97: 481-

484.

STASKOA, . B., R. M. HORRALLA, .D. HASLERA, ND

D. STASKO. 1973. Coastal movements of ma-

ture Fraser River pink salmon (Oncorhynchus
gorbuscha)as revealedby ultrasonictracking.

J. Fish. Res. Board Can. 30: 1309-1316.