Author: Lois A. Harwood

Publisher:

Published: 2002

Total Pages: 24

ISBN-13:

"The ringed seal is an important element of the arctic marine ecosystem, both as the main prey of polar bears, and a major consumer of marine fish and invertebrates (Smith 1987). It continues to be an important species in the subsistence harvests and economy of Holman, as well as in Sachs Harbour, Tuktoyaktuk and Paulatuk (Harwood et al. 2000). Seals are harvested for human and dog food and for pelts used in handicrafts and clothing. Over the past three years, four ringed seals were tagged in each of 1999, 2000 and 2001, with satellite-linked transmitters. The seals were captured near the Inuvialuit communities of Holman (1999 and 2000) and Paulatuk / Cape Parry (2001), NT, Canada. For 2002, we plan to conduct one further year at the Cape Parry site and in 2003 move to the southeastern Beaufort Sea out of Tuktoyaktuk or Sachs Harbour. Study Objectives: The specific objectives of the study are to: enhance the utility of an existing long-term, community-based seal monitoring program as a tool for studying ecosystem health and productivity; in a community-based program, to develop local expertise in the application of satellite tags to ringed seals in the Inuvialuit Settlement Region; facilitate partnering of industry, government, the Inuvialuit and the private sector in a long-term, ecosystem-based research; document the range and movements of adult, adolescent and young-of-the-year ringed seals from the Safety Channel (Tahiyuyak) area near Holman, from the Cape Parry area of Amundsen Gulf, and the Beaufort Sea offshore of the Mackenzie Delta and Tuktoyaktuk Peninsula areas, from early summer through to late spring; examine the depth and duration of ringed seal dives, time at surface, and distribution and movements of tagged seals in relation to ice conditions and oceanographic features in these areas (depicted in satellite imagery), as a means of elucidating important feeding locations within the region. ... Migration Routes & Proximity to the Snapper: The migration routes of two of the seals (11747, 5092) in Zones A and B followed a linear route in a southwesterly direction, offshore of the Tuk Peninsula and Mackenzie Delta (Fig. 1). The duty cycling of the tags started in Zone B, and thus the tags were "off" for part of the time that two of the seals were in the lease area (Sept. 27-29, 2001). Tracks for this area had to be interpolated from the locations available before and after the interruption due to the duty cycling of the tags. Three seals spent 2 d (5092), 4.5 d (11747) and 6 d (21212) travelling from east to west through Zone B. The closest that seal 5092 came to the operating Snapper was estimated to be 49 km on Sept 28 (Table 3). Seal 11747 followed a similar track as seal 5092, however then altered course to the south and traveled directly through the western portion of the lease area. This seal was interpolated to have come within 18 km of the operating Seismic vessel on September 28, 2001 (Table 3). This seal continued its migration, eventually arriving at the Yukon coast. This is an important late summer feeding area for both ringed seals and bowhead whales (Smith et al 1973; Harwood 1989; Harwood and Stirling 1992). Seal 21212 followed a similar westward path as 11747 and 5092 in Zone A, however altered course to a northward direction part of the way across Zone A. The seal continued in a north-westerly direction, then moved to the southwest following the shelf break zone through the rest of Zone B. This seal passed within 57 km of the Snapper on October 3. The shelf-break zone is a well-known feeding area for ringed seals and bowhead whales during the open water period (Harwood and Stirling 1992). The comparison of seal movements and Snapper activity presents a unique opportunity to examine the movement of ringed seals through an area of industrial activity. The duty cycling interruption and the small sample size (n=3) precludes drawing firm conclusions as to possible short-term effects (e.g. avoidance re sponses) or lack thereof. However, on a regional scale, it appears that the seals completed their migration from east to west unhampered, following similar routes and travelling at similar rates as each other. The diversion of seal 21212 to the shelf break zone was likely related to feeding, although it cannot be discounted that this could have been a "detour". The point at which the seal altered it's course was an estimated 110 km from the vessel, and this is beyond the distance at which a seal would be expected to be disturbed or possibly even detect an operating ship. In all cases, the seals migrated through Zone B, and into Zones C and D at similar rates and along similar headings throughout their rapid westward migration"--ASTIS [online] database.