744 



Fishery Bulletin 98(4) 



1020 m on each side and survey expansion factors 

 of 6.8 for the first survey and 9 for the second. 

 Resulting estimates would be 6.8 and 9 groups (38 

 and 50 whales), with approximate 90% upper CLs 

 of 25.0 and 33.8 (119 and 157 whales, if mean group 

 size was 5.6). These estimates and confidence limits 

 were imprecise and did not account for the uncer- 

 tainty of mean group size or for the known lower 

 bound on numbers. 



The large tidal range in southern Ungava Bay 

 creates extensive foreshore flats, and few beluga 

 whales were sighted from the observation points on 

 land. In 1992, 160 scans made over 35 days between 

 5 Aug. and 30 Sept. showed a total of 24 individu- 

 als. In 1993, 145 scans over 29 days in June and 

 July resulted in four sightings totaling 8 individu- 

 als; 68 scans over 15 days in August and September 

 resulted in three observations totaling 30 individu- 

 als. The largest count in any sighting was 17. 



Discussion 



N 

 58 



57 



55 



Northbound sieluines 

 Southbound sightings 



^'si 77-20 



70-1001 



75-901 

 1-", 



W^~  2 



these two sightings were 

 - hkely the same large group, 

 seen on both passes 



79 



78 



77 



76 



75 W 



The 1993 estimate of surface-visible beluga whales 

 in James Bay, about 3140, was 2.6 times that of the 

 previous survey (Smith and Hammill, 1986). In that 

 sui^vey, flown in early August, ice cover was still 

 present in northwestern James Bay; most groups 

 were composed of fewer than 5 animals and they were dis- 

 tributed in the southern part of James Bay (Smith and 

 Hammill, 1986, Fig. 1). In the present survey, there was 

 no ice and there were many observations of larger groups. 

 The highest densities were north of Akimiski Island and 

 up the western side of James Bay, where many groups 

 were found in shallow turbid water close to shore (Fig. 5A). 

 The beluga whales may have been distributed differently 

 in the two surveys because of the ice that still remained at 

 sui-vey time in 1985. 



It is difficult to ascertain the origin of this population. 

 Significant numbers of beluga whales were once reported 

 wintering in James Bay (Jonkel. 1969) prompting the 

 suggestion that a large part of that population might be 

 resident (Sergeant, 1986). However, a resident population 

 could not increase fast enough to account for the difference 

 between the 1985 estimate and the present one ( Eberhardt 

 and Siniff 1977; Sergeant, 1981; Kingsley, 1989; Doidge, 

 1990). In 1985 there was significant ice cover in northwest 

 James Bay, and beluga whales moving into James Bay 

 from southwestern Hudson Bay may have been delayed by 

 the ice in 1985, and not in 1993. However, Richard ( 1993) 

 suggested that the principal southward spring migration 

 route for James Bay beluga whales may be down the 

 east coast of Hudson Bay, in which case ice in northwest 

 James Bay would not have been a barrier. Alternatively, 

 the populations in western and southwestern Hudson 

 Bay (Richard et al., 1990; Richard, 1993) may have been 

 colonizing James Bay. A small fraction of the estimated 

 23,000 beluga whales of the western Hudson Bay stock 

 would have had a large effect on survey counts if they had 

 been present in James Bay. 



Figure 6 



Sightings of beluga whales on coastal aerial survey of eastern 

 Hudson Bay. 21 August 1993. 



The estimated density of beluga whales in eastern 

 Hudson Bay was slightly greater than the 1985 tran- 

 sect-survey estimate (Smith and Hammill, 1986 Table 

 1). However, for the latter survey, strip transects (with 

 a total width of 2000 m) were used. This distance prob- 

 ably exceeds the range at which beluga whales can be 

 effectively counted in a survey in the Beaufort Sea. With 

 the same platform, target species, and type of aircraft 

 window, Harwood et al. (1996) estimated an effective 

 strip width of about 1300 m. The 1985 strip-transect 

 estimate may have been biased downward in relation to 

 the present sur-vey In 1985, 200 beluga whales were 

 counted; in 1993, 150 whales were counted on the same 

 transects. 



Few beluga whales were seen on the coastal survey of 

 eastern Hudson Bay in 1993. There were no large con- 

 centrations in the mouths of rivers, but scattered small 

 groups and probably only one large group. The total was 

 less than 150 individuals. The land-based observations in 

 1993 also did not record large groups in the estuaries. 

 Therefore, the transect sample survey estimate probably 

 did not have large errors due to inefficient sampling of 

 large estuarine concentrations. In 1985, a total of 481 

 whales were counted on the eastern Hudson Bay coastal 

 survey, including concentrations in Richmond Gulf and 

 in the estuaries of both the Little Whale and Nastapoca 

 rivers (Smith and Hammill 1986), and land-based obser- 

 vations in 1984 counted as many as 200 individuals in the 

 Nastapoca estuary (on 24 August: Caron and Smith, 1990) 

 compared with the 1993 maximum of 53. 



Transect sample sun'ey and nearshore total-count indi- 

 ces apparently corroborate the finding that numbers in 



