1. Seal Monitoring
Annual Monitoring of Ringed Seals:
Holman, NT (1992 - ongoing)
and Sachs Harbour (2004-2008)
Annually from 1992 and continuing to the present time, approximately 100 ringed seals taken in the regular subsistence harvest by hunters from Holman, NT, have been sampled and measured as part of the "Holman Seal Monitoring Project". The study builds on work done in this area in the 1970's and the 1980's by the Dept. of Fisheries and Oceans and the Canadian Wildlife Service (CWS). The project is funded by the Fisheries Joint Management Committee (FJMC), delivered by the Holman Hunters and Trappers Committee (HTC), with assistance from the Dept. of Fisheries and Oceans (DFO) and EMC EcoMarine Corporation. In 2004, we added a second monitoring site at the community of Sachs Harbour, NT. Funding for both studies is provided by the Fisheries Joint Management Committee and by the Dept. of Fisheries and Oceans. The US Minerals Management Service provides funding for the Sachs Harbour study as well.
We examine seal body condition (fatness) and two parameters of seal reproduction, ovulation rate and percent pups in the harvest. These parameters were selected because (1) they varied with changes in the seal population during work in this same area in the 1970's, and (2) it was possible and practical to monitor these aspects over the long-term through a harvest-based study in the community of Holman. In all the years tested, including work done in the 1970's in this same area, seal condition (fatness) was poorest in 1974 (the heaviest ice year on recent record) and best in 1998 (the earliest break up/longest open water period on recent record).
Also in 1974, about half the females were not reproducing. In eastern Amundsen Gulf, 1974 was the most severe ice year on recent record, with the fewest number of open water days (28 days). There were no years from 1992 to 1998 which compared to 1974 in terms of hardship for the seals.
In 1998, the ice cleared 43 days earlier than the average clearing date for the 1990-1998 period, and there were 185 days of open water. The early break up led to some pups not being able to be nursed properly or fully. Those at the outside edges of the seal habitat were affected the most. Many starveling seals were found, some had rocks and feathers in their stomachs. This hard time for pups came at a time when the rest of the seal population was having the best feeding year on record as evidenced by their fatness (See Graph of blubber thickness below).
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 Seal Monitoring Results, 1992-2005view details |
Seal Monitoring Results, 1992-2005 view details |
The photo shows three seal pups, all borne in 1998, that were taken in the June subsistence harvest near Holman. The range of size and condition found in the pups that year was striking. The pup on the left was
larger and fatter than average, while the middle pup depicts slightly lower than average condition. The pup on the right was a starveling.
The early break up apparently led to an interruption in the lactation period for seal pups located at the periphery of the core breeding habitat. The apparent effects on growth and condition of unweaned pups came at a time when marine food appeared to be abundant and available to all age classes of ringed seals.
The project is continuing at the present time, with John and Emma Alikamik monitoring seals in the Holman harvests from early June through to early August. The project in Sachs takes place during July and August annually, for 2004-2008. The Sachs Harbour monitor is Jeff Kuptana. Harold Wright of Holman assists with the seal project as well, through preparation of the aging materials and analysis of the reproductive tracts.
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