Behaviour of ringed seals tagged with satellite transmitters in the North Water polynya during fast-ice formation

Abstract

To gain insight into the use by ringed seals (Phoca hispida) of the North Water polynya (northern Baffin Bay), we monitored the movements and diving behaviour of eight ringed seals caught in the fjords of the Thule (Avernarsuaq) area in Northwest Greenland. The animals were caught in August-September 1996 and equipped with satellite transmitters. Contact with the seals was maintained for up to 146 days. Two of the seals left the study area soon after being equipped, one moved north to the Kane Basin and one moved to southeastern Baffin Island. The departure of the other six seals from the fjords was apparently related to the formation of landfast ice. After formation of the polynya, all positions were close to the edge of the fast ice in the Thule area. Of the six seals that stayed in the North Water, three females preferred areas with shallow water (<100 m), while three males with larger body mass remained mainly in areas with deeper waters (>100 m). The "shallow-water" seals dove significantly more frequently to depths of less than 50 m than the "deep-water" seals, whereas the deep-water seals made significantly more dives that were deeper than 50 m. However, all seals occasionally dove to depths of more than 250 m.

Movements and diving of adult ringed seals ( Phoca hispida ) in Svalbard

“…The transmitters lasted on average more than 6 months, a good result compared with other ringed seal studies with average results of 99 days (Teilmann et al 1999) and 69 days (Heide-Jùrgensen et al 1992). This may be because the equipment has improved after Heide-Jùrgensen et al 's (1992) pioneer project, and because the present study only deployed transmitters on adult animals.…”

“…Depth bin lower limits were: 4,8,12,16,20,30,40,50,100,150,200, 300, 400, >400 m observations on ringed seals from Greenland. A total of 12 ringed seals were tagged with satellite transmitters in 1988and 1996(Heide-Jùrgensen et al 1992Teilmann et al 1999). However, unlike in Svalbard where all the tagged seals were adults, only 2 of the 12 tagged Greenland seals were adults.…”

“…However, unlike in Svalbard where all the tagged seals were adults, only 2 of the 12 tagged Greenland seals were adults. One Greenland seal crossed Ban Bay and moved 2000 km from the tagging site (Teilmann et al 1999), but most of the other seals undertook shorter coastal movements until they left the fjord areas in September/October and moved oshore into the North Water polynya. These movements were apparently related to the formation of land-fast ice in the fjords (Teilmann et al 1999).…”

“…One Greenland seal crossed Ban Bay and moved 2000 km from the tagging site (Teilmann et al 1999), but most of the other seals undertook shorter coastal movements until they left the fjord areas in September/October and moved oshore into the North Water polynya. These movements were apparently related to the formation of land-fast ice in the fjords (Teilmann et al 1999). This indication of limited movement is supported by Kapel et al (1998), who found that 31 of 38 recaptured tagged ringed seals in Greenland were caught within 120 km of the tagging site up to 14 years after tagging.…”

“…Some ringed seals may undertake long-distance movements of up to 1000 km and, in one case, more than 2000 km (Smith 1987;Heide-Jùrgensen et al 1992;Kapel et al 1998;Teilmann et al 1999).…”