Distribution and Movements of Belugas, Delphinapterus leucas, in the Canadian High Arctic

Thomas G. Smith Department sf Fisheries and Oceans, Biological Sciences Branch., Pacific Biological Station, Manaimo, BC V9R 5K6, Canada

and A.R. Martin Sea Mammal Research Unit, c/o British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET, UK

Smith, P.G., and A.R. Martin. 1994. Distribution and movements of belugas, Delpkinapterws lewcas, in the Canadian High Arctic. Can. ). Fish. Aquat. Sci. 51: 1653-1663.

Belugas, Delphinapterus Beucas, move into the coastal waters of Somerset Island as soon as the annual Iand- fast ice breaks asp in late June - early july. Six bays or inlets which receive the outflow of rivers are the major areas of summer aggregation. Belugas captured and equipped with satellite-lin ked UHF transmitters in Cunningham Inlet (Barrow Strait), Elwin Bay (Prince Regent Inlet), and Creswell Bay moved west into Peel Sound where they frequented two other estuaries. Rapid and directed movement out of Peel Sound occurred in late August. All of the animals which transmitted locations into September or October moved to eastern Devon lsland and Jones Sound. The longest period of transmission was 75 d, lasting until mid- October. Belugas tagged in three different locations around Somerset island in the summers of 1988-93 showed a we1 1-defined and consistent pattern of behaviour. Aerial surveys done during this period confirm that the vast majority of belugas in this region are involved in these seasonal movements.

hes belugas, PBeBphinapterus leucas, entrent dans les eaux littorales de l'ile Somerset des la d6b2cle annuelle de la banqasise c6ti+re, entre la fin de juin et le debut de juillet. Six baies ou bras de mer dans lesquels se deversent les cours d'eau constituent les principales nones de regroupement estival. bes belu- gas captures et equip& d'emetteurs UHF a liaison satellitaire dans I'inlet Cunningham (detroit de Barrow), la baie Elwin (inlet Prince Regent) et la baie-Creswell, se sont deplaces vers I'ouest jusqu'au detroit de Peel, oG i l s ont frequent6 deux autres estuaires. A la fin du msis d'aoirt, on a observe un mouvement rapide et dirige de sortie du detroit de Peel. Pous Bes animaux dont la localisation a et6 faite par [eur emetteur en septembre ou octobre se sont deplaces vers B'est jusqu'a I'ile Devon et fe detroit de Jones, La periode d'6mission la plus longue a kt6 de 7% jours et a dure jusqu'a la mi-octobre. bes belugas marques a trois different5 endrsits autour de I'iie Somerset au cours des ktes 1988 2 1993 ont montre un profil de com- portement bien de f i~ i . bes lev& aeriens effectues durant cette pkriode confirment que la vaste majorit6 des belugas dans cette region participe a ce mouvement saisonnier.

Received lu ly 73, 1993 Accepted February jr 4,p 7 994 (JC006)

ost belugas, Delphinapteru,~ leucas, occupying the eastern Canadian High Arctic during the ice-free months of July and August are found in the coastal

shelf habitats around Somerset Island, N.W.T. This region, including Barrow Strait and parts of Lancaster Sound, is usually covered by land-fast annual sea ice from October to late June. Aerial surveys of belugas in autumn (Finley and Johnson 1977) have shown a movement out of Barrow Strait and eastward through Lancaster Sound. Belugas have been reported to overwinter in the large North Water polynya of Baffin Bay (Finley and Wenaud 1980), but it is believed that most of the High Arctic stock spends the winter in the pack ice off the west coast of Greenland between Disks Bay and approximately 63"N (Vibe 1950; Kapel 1977). Recent surveys in west Greenland (Heide-Jorgensen 1992) indicate that the area south of 65"N is no longer important as winter habitat for belugas, possibly because of excessively high catches there in drive-net fisheries between 1917 and 1938. The main wintering concentrations are presently found between 67"N and 69"N, and not more than $0 km from the west Greenland coast.

The little evidence to date points to a shared common stock of belugas between the eastern Canadian High Arctic and Greenland. The continuing high annual harvests in west Greenland and small harvests in Canadian waters impose an annual estimated removal of 1200 animals per year (IWC 1991). This population has been estimated to comprise between $300 and 18 600 animals, uncorrected for those below the water surface when the survey aircraft passed overhead (Smith et al. 198%). Even if the upper bound of the estimate is inflated by a factor of 1.42 to compensate for these missed whales (Martin and Smith 1992), the total harvest probably far exceeds the sustainable yield for any odontocete whale population (Sergeant 1981; Burns and Seaman 1988; Doidge 1990). Added to the harvest are the frequent ice entrapments of belugas which, combined with opportunistic hunts at these "sassat9' (Porsild 19 1 8; Freeman 1968; Kapel 1977; Heide-Jorgensen B994), result in signif- icant added mortality. As recently as February 1990, a "sassat" occurred in Disko Bay where an estimated 580 bel- ugas were killed by Inuit hunters. Comparisons of relative abundance of belugas counted in Greenland waters during the

Can. 9. Fish. Aquat. Sci., Vol. 51, 1994 1653

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TABLE I. Details of' transmitter pack deployment on belugas at three sites on Somerset Island, N.W.T., Canada. Whales were captured atad released at the freshwater outlets of Cunningham Inlet (CI) (74"05'N, 93"49'W), Elwin Bay (EB) (73"33'N, 90"57'W), and Creswell Bay (CB) (72"43'N, 93'20'W) between 1988 and 1993.

Details of animal Release Transmitter Tag longevity

date Local time Place Fag No. tY Pe Length (m) Sex Age (d)

22 July 1988 13:58 27 July 1989 17:33 30 July 18:37 17 July 1990 1207 17 July 17:22 17 July 17:22 18 July 15136 23 July l3:00 21 July 1991 1224 27 ~uay 21145 28 July 21:25 31 July I6:00

1 Aug. 12:50 26 July 1992 1 %:06 23 July 15:0B% 23 July 14: I0 25 July 20:40 21 July H 3:30 13 Aug. 1993 0245 14 Aug. 14:OO 15 Aug. 18:15 15 Aug. 15:30 14 Aug. 12150

Location Location Location Location and depth Location Location Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth Location and depth

Adult Adult Subadult Subadult Adult Subadult Adult Adult Adult Adult Subadult Adult Adult Adult Adult Adult Adult Adult Adult Adult Adult Subadult Adult

FIG, I. Map of Somerset Island and adjacent open-water areas occupied by belugas, with the five (8-5) main areas of estuarine aggregation.

winters of 1981 and 1982 with surveys in 1990 and I991 In light of the need for a reassessment s f the size and seem to indicate a significant decline in numbers consistent status of this stock, we review QW knowledge sf the seasonal w i t h t h e e x p e c t e d e f f e c t o f thehighccsntinamingannual dis~butisnandnaamkrssfbelugasfoundi~ntheirsumme~ng harvests (Heide-Ssrgensen et al. 1992). areas in Canadian waters and present direct evidence on

1654 Can. J. Fish. Aquat. Sci., Vob. 51? 1994

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FIG. 2. (a) Extent of land-fast ice during a typical winter in Barrow Strait and Eancaster Sound. (b) Initial ice breakup from June to early July. Arrows indicate direction of travel of belugas in early summer. (c) Further clearing of ice in Bate July in Barrow Strait and Prince Regent Inlet. Arrows indicate direction of travel by belugas in late July - August. (d) Late August - September distribution and movement (arrows) s f belugas from Peel Sound.

seasonal movements and migration routes from our studies of belugas equipped with satellite-linked UHF transmitters.

The coastal areas of Somerset Island including Barrow Strait, Prince Regent Inlet south to Creswell Bay, and Peel Sound south to Bellot Strait were surveyed opportunistically by Bell 206 helicopter or Twin Otter aircraft during July and early August from 1980 to 1992. Flight levels of 340 and 170 rn as1 were selected, the lower level when taking vertical photographs through a hole in the chin bubble sf the Bell 206B helicopter using a Hasselblad 70-mm-format camera equipped with an $0-rnm lens.

From 1988 to 1993, 23 belugas, 16 adult and five subadult females and two adult males, were captured by driving them into the shallows and then restraining them using hoop nets, fitted with satellite-linked UHF transmitters and immediately released (Martin and Smith 1992) (Table 1). Thirteen were captured at Cunningham Inlet, five at Elwin Bay, and five in

the Creswell Bay area (Table I ; Fig. I). The transmitter specifications, package design, and attachment procedures have been described in Martin and Smith (1992) and Martin et al. (1993). Details of service Argos, hhe satellite data reception system used, and estimates of data accuracy are given in Fancy et A. (1988) and CLSIService Argos (1989).

Each of our transmitters was identified by a unique number and transmitted up to 256 data bits derived from onboard sensors. The early packages transmitted signals used to determine location only whereas the most recent also relayed both detailed and summary data on dive profiles and swim- ming velocity (Table 1).

Average speeds of travel were only estimated between pairs of Argos-derived high-quality locations (location of quality = 2 or 3). To further reduce error, we restricted our data set to locations separated by time intervals of 25 h.

Data were analysed using the Proc. Sort procedures of SAS (%AS Institute Inc. 19858). Grid location analysis was done by assigning numbers to geographic grid squares of 289atitude by l o longitude to cover the entire study area.

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Unless otherwise stated, the following results derive from a combination of aerial survey, radio-tracking, and ground- based observational data.

Results

Beluga Movements in Relation to Ice Conditions and Pattern of Breakup

Access by whales to their summering areas around Somerset Island is limited by the land-fast ice which forms during the winter and spring months in Lancaster Sound, Prince Regent Inlet, Barrow Strait, and Peel Sound. The timing of breakup depends heavily on the winter location of the fast-ice edge which can vary greatly from year to year (Marko 1982; Gorman 1988). In an average year the ice edge forms across Barrow Strait from Prince Leopold Hsland to Maxwell Bay on Devon Island (Fig. 2a).

In June, as shore leads develop, both southward into Prince Regent Inlet along the east coast of Somerset Island and westward into Barrow Strait along the north coast, whales begin moving to their areas of summer aggregation (Fig. 2b). A consistent feature of this breakup pattern is a series of large leads, apparently caused by coastal upwelling, running parallel to the northern Somerset Island coastline from Prince Leopold Hsland (Prisenberg and Bennett 1987). By late July the fast-ice edge has usually receded to Eowther Island, but ice cover in Barrow Strait is quite variable as broken ice shifts position and ice empties out of adjoining channels.

In Cunningham Inlet, a main area of beluga concentration in July (Smith et al. 1992), fast ice begins to melt near the delta as a result of river outflow in the latter part of June. Tidal currents are believed to initiate breakup at the northern entrance to the inlet, followed by melting along the western shore. The last ice to remain in the inlet is usually found in the northeast and southeast portions of the bay. These areas are normally ice free by mid-July.

During the same period, Prince Regent Inlet has cleared of ice, allowing whales access to Elwin Bay, Batty Bay, and eventually Creswell Bay, all areas of fresh warm water influx where the nearshore ice has melted (Fig. 2c).

Peel Sound on the west coast of Somerset Island retains its ice into August. A shore lead develops along the Somerset coast, allowing belugas to penetrate southwards into Peel Sound, where they concentrate along the floe edge and in leads as the ice breaks up. Belugas concentrate at the entrance to a small river north of Wadworth Island. Later, when the ice has broken up completely in Peel Sound, large numbers of belugas concentrate in the freshwater outflow of Coningham Bay, situated on the coast of Prince of Wales Island in Franklin Strait (Fig. 2d).

Number of Belugas in Areas Adjacent to Somerset Island

From coastal aerial surveys in areas adjacent to Somerset Island and land-based counts made mainly at Cunningham Inlet (Smith et al. 1992), we have compiled a general picture of the summer distribution and autumnal dispersion of belugas (Table 2). When coastal surveys were flown from late July into August (e.g., 1988 and 1992) including the main areas of aggregation such as Cunningham Inlet, Creswell Bay, and Peel Sound, the numbers of belugas and timing and pattern of dispersion were quite similar between years.

Can. 9. Fish. Aquat. Sci., VoE. 51, 1994

Belugas in the Barrow Strait area initially concentrate in Cunningham Inlet, where numbers build rapidly from mid- July to the end s f the month. During that period, numbers sf belugas frequenting Eiwin Bay and Batty Bay, in Prince Regent Inlet. also increase. Our general impression from those surveys was that belugas in Prince Regent Inlet moved down to Creswell Bay where numbers peak in the early part of August; some 4000+ belugas are found in the shallow bays receiving the outflow of freshwater from the different arms of the Creswell River.

By the end of the first week of August, there is a major shift in the distribution of the belugas centred around Cunningham Inlet in Barrow Strait. The ice in Peel Sound begins to break up rapidly and the whales from Barrow Strait push southward into the shore Beads and fractured ice. Often the floe edge establishes itself briefly in an east-west direction across Peel Sound from Somerset Island side near Wadworth Island - Birmingham Bay to Back Bay on Prince of Wales Island. There, thousands of belugas aggregate, with as many narwhals, k f ~ n s d r ~ n monocerss, and numerous harp seals, Phsccd groenlandicw. Belugas push into the mouth of an unnamed river (73"30fN, 95"42W) north of Wadworth Island where they exhibit the same rubbing behaviour (Smith et al. 1992) as seen earlier in Cunningham Inlet. When the ice finally permits passage, belugas push further south into Franklin Strait and usually remain in the area of Coningham Bay with its freshwater outflow and the adjacent deep marine trench. Rarely, belugas push still further south, where they are occasionally hunted by the Inuit from Spence Bay (69"30fN).

We know less of the dispersion of the large concentration of belugas found in Creswell Bay during August. During this study, belugas were sighted south of Creswell Bay as f a as Bellot Strait, but while significant numbers of narwhals were seen swimming west against the strong currents of Bellot Strait, we have never documented belugas using this route to reach the large aggregation of this species in the Coningham Bay area. Significant numbers of belugas were, however, seen in mid-August along the southern coast sf Devsn Island, often in Gascoyne Inlet and Radstock Bay. Belugas are possibly attracted to these areas because of the occasional nearshore presence of large schools of Arctic cod, Boreogradus saida (Welch et al. 1992).

Effects of Capture on Belugas in Estuaries

We tagged belugas at three sites, Cunningham Inlet, Elwin Bay, and Creswell Bay, which were very different from each other with respect to the disturbance which was imposed on the whales during the capture process. Cunningham Inlet and Elwin Bay were both defined and enclosed bays whereas the captures at Creswell were spread out along an area of coastline. The larger of the two bays, Cunningham Inlet, allowed us to isolate our capture effort and minimize dis- turbance to other whales. This was achieved by keeping our activities behind an acoustic barrier, a sandspit on the south- west side of the Bay. At Elwin Bay, it was necessary to move our boat across the whole Bay to capture the whales in the river channels. Because of the large area in which we operated in Creswell Bay, we could not measure the effect of our captures on the whales in the area.

At Cunningham, we caused the Inlet to be vacated com- pletely after 13 of 21 capture attempts (62%) whereas at Elwin, four of four attempts emptied the Bay completely.

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TABLE 3. Number s f attempted captures. frequency of complete disturbance to the estuary (all whales departed), and minimum, maximum, and average time for the first belugas to return to Cunningham Inlet and Elwin Bay.

Time to return (h) No. of No. of times

capture attempts Inlet vacated Min. Max. Avg.

Cunningham Inlet 1988 5 4 (80%) 11 21 17.6 1989 6 6 (100%) 6 27 15 1990 3 0 (0%) 5 21 12 199 1 7 3 (43%) 11.5 29 17

Elwin Bay 1992

TABLE 4, Number of tagged belugas which remained in the capture areas after release or which left and later returned.

Time to first return (h) Total tags deployed No. of belugas staying No. of belugas

and functional or returning to estuary which did not leave Miaa. Maw. Avg.

Cunningham Inlet 1988 4" 1989 I 1990 5 1991 4

Elwin Bay 1992 4 4 0 7 143 41.5

'Three conventional VHF and one PTT. 'stayed together while travelling; possible mother with older juvenile offspring.

In both areas, belugas returned to the Bay within 12-17 h (Table 3). Of 17 tagged belugas, 11 (65%) returned to the estuary after capture and three belugas did not leave the estuary (Cunningham Inlet) for a period of hours or days after capture. Of those whales which left immediately after capture and returned, the time lapse ranged from 7 to 143 h (Table 4).

Utilization of Estuaries and Offshore Areas by Belugas

We have identified six principal estuarine areas used by belugas on the coasts of Somerset and Prince of Wdes islands (Fig. 1). In the three years of study at Cunningham Inlet, when transmitters functioned for sufficient periods of time, none of the tagged whales moved east toward Prince Regent Inlet. The 1990 tag information, which ended by 16 August, indicated a movement into Peel Sound, while the 1991, 1992, and 1993 studies reinforced this picture with more details on the use of two estuarine habitats, the small unnamed river emptying into Peel Sound at Birmingham Bay and the river emptying into Coningham Bay on the coast of Prince of Wales Island.

In 1992, when the belugas were all caught at Elwin Bay and transmissions lasted into late September, we gained a more detailed picture of large-scale movements and use of estbaries. Whales released from Elwin Bay used Batty Bay, but did not travel south to join the large numbers of belugas in Creswell Bay. Instead the general movement was to the west into B m w Strait, with thee of the five belugas ventur- ing briefly into Cunningham Inlet. The movement appears to have been mainly directed toward Peel Sound, where all four belugas with still-functioning transmitters congregated in the small estuary north of Wadworth Island (73"30rN,

95"42'W) and eventually penetrated south to Coningham Bay. Of the three functional tags applied in 1993 at Creswell

Bay, only one whale ventured into Peel Sound and Franklin Strait. None of the three spent much time in estuaries, prob- ably because of the late date of their captures. The only other estuaries frequented by two of those three animals were those of Batty and Elwin bays in Prince Regent Inlet.

The highest frequency of transmissions was received from the locations of Cunningham Inlet and Elwin Bay in July and the small estuary north of Wadworth Island and Cunningham Inlet in August. Coningham Bay was most important as an aggregation area in August 199 1, when ice conditions allowed belugas to penetrate into the area as early as 6 August. In 1992 when the ice was much heavier, the small river estuary north of Wadworth Island became the most important area of aggregation in Peel Sound. One whale tagged at Elwin Bay on 23 July reached this area on 6 August. In 1993, ice blocked access to this estuary, but allowed belugas to pass south along the west side of Peel Sound. By September, all belugas had ceased using estuaries.

The proportion of time spent in estuaries by belugas in July and August varied from 0.005 to 0.12. Of the five tags which were applied in mid-July and transmitted until the end of August, the mean proportion of time spent in estuaries was 0.082 (Table 5). It is obvious that belugas tagged late in the season, as in 1993, frequent estuaries much less.

Belugas also used the waters close to estuaries more fre- quently than other locations. Of the five whales whose trans- missions were received from July to at least the end of August the total proportion of their time spent in the estuary or in the offshore area of the grid rectangle which included the estuary varied from 0.29 to 0.38 (Table 6).

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TABLE 5. Estuarine utilization by individual beluga whales tagged at Cunningham Inlet, EBwin Bay, and Greswell Bay. Other estuaries occupied include Batty Bay, north of Wadworth Island, and Coningham Bay (see Fig. 1).

Estuaries occupied Total hours tagged, Proportion of total hours Date tagged Date ended Tag No. (see Table 1) (Fig. 1) July and Aug. (July-Aug.) in estuaries

Cunningham, 1990 15 July 16 July 23 July 15 July 15 July

26 July 27 July 21 Aug. 16 Aug. 6 Aug.

Cunningham, 199 1 21 July 29 July 31 July

1 Aug.

18 Aug. 22 Aug. 13 Sept. 4 Aug.

EBwin, 1992 27 July 24 July 24 July 27 July

17 Sept. 4 oct.

26 Sept. 28 Sept.

Creswel1, 1993 13 Aug. 15 Aug. 14 Aug.

I I act. 5 Sept.

28 Sept.

Of the five belugas tagged in July and which transmitted data into at least mid-September, one was tagged at Cunning- ham Inlet and the rest at Elwin Bay. Peel Sound was by far the most heavily used of the major areas around Somerset Island by all those animals, ranging in total proportion of time tagged from 0.19 to 0.33 in the offshore areas not including time in the estuaries.

The offshore waters of Barrow Strait and Prince Regent Inlet were little used by the whales during the whole period. Eancaster Sound became important again during autumnal eastward migrations (Table '7).

are available ( N 2 38) lie in the range of 1.1-1.85 kmbh (Table 9).

During the period of eastern migration from Peel Sound through Barrow Strait and into Eancaster Sound, there is an apparent fast directed movement which brings belugas along the southern coast of Devon Island and eventually into the area of Philpots Island (74"55'N, 79"4BB'W) and southern Jones Sound in late September. In 1998, whale No. 8'750 moved through Barrow Strait covering 298 km in 85 h (1.6 kmbh). Om 7 and 8 September, it apparently increased its speed to move 132 km in 22 h (5.99 km/h) to longitude 80"W. In 1992, speeds of 2.11, 3.54, and 3.8- 4.9 km/h were estimated during similar movements for three whales over distances of 167-522 km. Caution should be used in evaluating all these estimates because of the poten- tial error from poor location qualities and the small num- ber of samples. More accurate speed estimates can only be made in the future from direct measurements taken with onbsard velocity meters.

In 1990, four of the five belugas tagged at Cunningham Inlet were released on 15 or 16 July; one other was released on 23 July. All of the early tagged whales moved into Bmow Strait and three returned one or more times to Cunningham Inlet. All animals moved into Peel Sound by 26 July. There appeared to be a general movement of Cunningham Inlet belugas joined by some of the tagged whales starting around 23 July.

All seven belugas whose transmitters lasted for 3 wk or more in 1992 or 1993 moved to the eastern coast of Bevon Island and three moved north into Jones Sound. The most easterly recorded location was at 72"10'W.

Timing of Major Movements

All of the belugas tagged at either Cunningham Inlet or Elwin Bay from 1990 to 1992 (a = 15) moved west into Peel Sound. Only one of three tagged in Creswell Bay in 1993 moved into Peel Sound. In 8990, when animals were tagged as early as 15 July, the earliest mival in Peel Sound was on 24 July. The latest mival in Peel Sound was a whale tagged in Elwin Bay on 26 July arriving on '7 August (Table 8).

Once in Peel Sound, belugas congregated at the floe edge, which crossed to Prince of Wales Island at the latitude of the river estuary north of Wadworth Island. Of 81 belugas with tags transmitting into at least mid-August, eight even- tually moved south into the Coningham Bay area, arriving as early as 29 July in 1991 and as late as 28 August in 1993.

Of the six whales transmitting data into September, depar- ture dates from Peel Sound occurred between 28 August and 7 September. The animals spent little time in Barrow Strait, moving directly east into Eancaster Sound between 30 August and 15 September (Table $1.

Speed of Travel and Individual Long-range Movements Discussion Travel speed calculated indirectly from location data can-

not yield much detail about maximum or minimum swimming capabilities. Our conservative estimates of average travel speed over large time intervals where sufficient sample sizes

The timing of breakup of sea ice in the coastal areas of Somerset Island is variable and dependent on many differ- ent factors (finsenberg and Bennett 1987). The arrival of k1-

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TABLE 6 . Time spent in major estuaries, their adjacent waters, and in major geographical areas around Somerset

Time in grid Total Time Time in Time Time in offshore time, in grid offshore estuary north of estuary north of Time in

Tag July- Cunningham offshore Barrow Wadworth Wadworth Coningham No. Aug. Inlet Cunningham Strait Island Island Bay

ugas at their traditional summer areas of aggregation is largely dependent on ice conditions (Smith et al. 1992), but was predictable within a range of about 14 d over a docu- mented span of 12 yr.

The coast of Somerset Island and southern Prince of Wales Island in Peel Sound are the main areas of beluga aggrega- tion during July and August, with some minor and transient use of the southern coast of Bevon Island. Animals in Prince Regent Inlet appear to follow belugas from Cunningham Inlet into Peel Sound, as the ice melts and breaks up there in early to mid-August. The large numbers of belugas occu- pying the Creswell Bay area persist there into the first weeks of August. One of the three tagged belugas in 1993 moved into Peel Sound; the other two occupied Barrow Strait and moved directly to Lancaster Sound. The late tagging of bel- ugas in Creswell in 1993 perhaps has not given us as clear a picture of their summer distribution as we might have obtained if animals had been captured in July.

There has been no indication that belugas from Creswell Bay ever use Bellot Strait to join the concentrations seen in southern Peel Sound. Finley and Johnson (1977) main- tained a watch in this area and also failed to detect belugas using the Strait. This is surprising, since we have often seen narwhals and harp seals moving through this narrow channel.

There are six principal sites of aggregation for belugas, all of them the mouths of river estuaries. On the east coast of Somerset Island are Elwin Bay, Batty Bay, and, further south, the Creswelll River estuaries. On the north coast is Cunningham Inlet in Barrow Strait. To the west in Peel

in Strait, is the small estuary north of Wadworth Island and the Coningham Bay estuary. Additionally, a few smaller streams and rivers are important, especially in the early part of summer while access to the main areas is blocked by ice. The small stream at Fellfoot Point near Maxwell Bay on Devon Island (74"3QrN, 88O35'W) and several small rivers on the Brodeur Peninsula, BafGin Island, are frequented by belugas. During the summer, belugas briefly frequent the small river at Gape Anne (74"05W, 94O44'W) on the north coast of Somerset Island, often after

previously visiting Cunningham Inlet, a short distance to the east. The use of estuaries is related to a synchronous moult which is promoted by contact with warm freshwater (St. Aubin and Geraci 1989; St. Aubin et al. 1990; Smith et al. 1992).

Animals from Cunningham Inlet often proceed into Peel Sound by way of the estuaries north of Wadworth Island and Coningham Bay. Belugas tagged at Elwin Bay followed the same pattern without spending any substantial time at Cunningham Inlet. The actual use of the specified estuaries during July and August accounts for only about 8% of the total time, but belugas spend from 29 to 35% sf their time in the areas adjacent to estuaries.

kt appears that belugas move in and out of estuaries to exploit feeding opportunities offshore. Persistent deep diving by belugas in areas of Barrow Strait outside Cunningham Inlet in the Franklin Trench outside of Csningham Bay prob- ably indicates the exploitation of deepwater prey (Martin and Smith 1992; Martin et al. 1993).

The movement into Peel Sound by most of the belugas tagged during this study might be directly related to feeding. The persistence of a floe edge could provide feeding oppor- tunities on ice-associated fauna (Bunbar 8 98 1 ). The presence of large numbers of harp seals and narwhals along these ice edges also leads us to believe that feeding is occurring and that it is an area of high food availability.

We do not know what triggers the apparent quick and directed movement of belugas northwards out of Peel Sound and eastward through Barrow Strait (Finley and Johnson 1977) and Laamcaster Sound (LGL 1983). This appears to occur regularly in late August - early September. Belugas make transient use of certain bays as feeding areas along the south Bevon coast. In late August - early September, large schools sf Arctic cod have been sighted in the bays along the southwestern coast (Welch et al. 19921, where belugas and seabirds feed heavily on them. During their rapid migrations to the east, belugas regularly frequent Crsker Bay (74"30WN, 83'20'W) and eventually stop in the area around PhiHpots Island. In October, some whales move

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Island and in Barry Channel.

Time in Time in Time grid Time grid offshore Time in grid Time Timing

offshore offshore Time in offshore Prince Time in offshore offshore between Coningham Peel Elwin Elwin Regent Batty Batty Lancaster distant

Bay Sound Bay Bay Inlet Bay Bay Sound quadrats

TABLE 7. Proportion of time spent in major geographical areas or moving between locations by UHF-tagged belugas between 24 July and 4 October 1991 and 1992.

Offshore Offshore Offshore Offshore Tag Total time Estuaries or Barrow Peel Prince Lancaster No. tagged (h) adjacent waters Strait Sound Regent Inlet Sound Moving

31 July - 13 Sept. 8750 1044 Q.245 0.024 0.336 0 Q 0.402 27 July - 19 Sept. 8752 138 1 0.2 15 0.01 0.265 0 0 0.3 18 24 July - 4 Oct. 8753 1741 0.463 0.015 0.315 0.856 0.03 1 0.174 24 July - 26 Sept. 8754 1549 0.3663 0.048 0.199 0.037 8.138 0.250 27 July - 28 Sept. 8755 1539 8.2127 0.030 0.293 0.059 0.278 0.107

TABLE 8. Dates of major movements s f UHF-tagged belugas.

Move to Tag Arrived Peel Arrived Move to Laneaster

Date tagged No. Sound Coningham Bay Barrow Strait Sound

Cunningham Inlet, 1990 15-20 July 5801 16 July 5803 23 July 5806 15 July $750 15 July $485 1

Cunningham Inlet, 199 1 21 July 5801 29 July 5805 31 July 8750

1 Aug. 8757

Elwin Bay, 1992 26 July 8752 28 July 875 3 23 July 8754

26 July 8755

Creswell Bay, 1993 13 Aug. 8750 15 Aug. 8753 15 Aug. 8755

24 July 24 July 27 July 248 July

25 July 31 July 2 Aug. 2 Aug.

5 Aug. 4 Aug. 5 Aug.

7 Aug.

22 Aug.

29 July 3 Aug. 5 Aug.

18 Aug. 17 Aug. (Only to

72"53'N) 18 Aug.

28 Aug.

Lost in Peel Sound 7 Sept. 30 Aug.

5 Sept. 15 Sept. 26 Aug. 30 Aug. Lost in Peel Sound

Sept. 5 Sept. 7 Sept.

7 Sept, 22 Aug. 2% Aug.

12 Sept. 24 Aug. 31 Aug.

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TABLE 9. Summary of travel speeds (km/h) from UHF-tagged belugas calculated from Argos- derived locations of quality 22 and time intervals between locations of 25 h.

Tag No. Avg. speed No. of measuremens No. of hours SD Maw. speed

north into Jones Sound and eventually some move west into Greenlandic territory where our last transmissions have been received. More information is required about the behaviour of belugas in this late autumn period, since no aerial surveys were conducted at that time.

One of the striking results of our study is the demon- stration that belugas in the Canadian High Arctic maintain a well-defined pattern of movement from year to year. Furthermore, the consistency of the behaviour sf the animals tracked by radio telemetry indicates that the pattern is adhered to by the great majority of the individuals in the stock. This picture became clearer and was reinforced when- ever aircraft were used to search the area in which one or more of the radio-tagged animals had been located via satel- lite. In every case, hundreds or thousands of belugas were found in the vicinity. We are confident that even this small sample of tagged animals (in relation to the population size) has been adequate to describe in broad terms the behavirsur s f the population as a whole.

There is an urgent need to reassess the size of this beluga stock which is, in all probability, shared by Canada and Greenland. Recent winter surveys (Heide-Jorgensen 1994) indicate significant declines since our latest estimates of stock size in 1981 (Smith et a%. 198%) because s f the high continuing harvests. Belugas are difficult to count because sf their clumped distribution, their ability to move long dis- tances in a short time, and because they can spend a signifi-

Bay, N.W.T. We also thank the Natural Environment Research Council U.K. and the Department of Fisheries and Oceans for continuing financial support. We acknowledge the great help of Gilly Banks, Charlie Chambers, Ollie Cox, Mike Fedak, Russell Gadbury, Colin Hunter, Bernie McConnell, and Kevin Nicholas of the Sea Mammal Research Unit for their dedicated and tireless efforts on behalf of this project. Peter Blesiuk, Pacific Biological Station, aided with the data analysis.

References

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Acknowledgements

We thank Hillary Adams, Kathy Frost, Haakon Hop, George Horonowitsch, Jack Orr, and Gary Sleno for their assistance with the field logistics and capture of the belugas. None of the work could have been done without the considerable aircraft support and logistic help provided by the Polar Continental Shelf Project, Department sf Energy, Mines and Resources, Resolute

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