. The Canadian field-naturalist. 1998 CURREN AND LlEN: OBSERVATIONS OF WhITE WhALES 31. ^'â¢â 'â¢if-T" J FMAMJ JASOND Month Figure 2. White Whale sightings by month, 1979-1992. cephala melas). Harbour Seals (Phoca vitulina). Grey Seals {Halichoerus grypus), and, increasingly, Harp Seals {Phoca groenlandica) may be significant competitors for food. Competition for food by humans may limit White Whale numbers as the waters of the northwest Atlantic have been heavily fished for many years (Reeves and Katona 1980; Finley, Hickie and Davis 1987). White Whales in the Arctic and Subarctic move i
. The Canadian field-naturalist. 1998 CURREN AND LlEN: OBSERVATIONS OF WhITE WhALES 31. ^'â¢â 'â¢if-T" J FMAMJ JASOND Month Figure 2. White Whale sightings by month, 1979-1992. cephala melas). Harbour Seals (Phoca vitulina). Grey Seals {Halichoerus grypus), and, increasingly, Harp Seals {Phoca groenlandica) may be significant competitors for food. Competition for food by humans may limit White Whale numbers as the waters of the northwest Atlantic have been heavily fished for many years (Reeves and Katona 1980; Finley, Hickie and Davis 1987). White Whales in the Arctic and Subarctic move into river estuaries in the summer months. Thus, another possible limiting factor may be the availabil- ity of suitable estuarine habitats in Newfoundland (Reeves and Mitchell 1989; Finley, Hickie and Davis 1987). Several theories have been proposed to account for this behaviour, including response to the movement of prey, and thermal advantages to calves and adults; however, no data support these theories (Watts, Draper and Henrico 1991). A more likely explanation for this behaviour is that the elevated temperature and low salinity of the estuaries assist the animals' annual molt and stimulate epidermal growth (St. Aubin, Smith and Geraci 1990). No data was available on the suitability of Newfoundland river estuaries for White Whales. The stock affinities of the White Whales sighted in Newfoundland and Labrador are unknown. Although the nearest population of White Whales occurs in the St. Lawrence River, an analysis of blubber polychlorinated biphenyl (PCB) levels of the Whales Gulch animal showed that the animal was from an Arctic or Subarctic population (Beland, De Guise and Plante 1992). Continued monitoring of extralimital White Whales and toxicological tis- sue analysis may yield further information on their stock affiliations. Acknowledgments We thank the following people for their sighting records of White Whales: Pierre Yves Daoust, Prince Edward Island Stranding N
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