Harvest-based Monitoring of Ringed Seal Body Condition and Reproduction in Amundsen Gulf, NT, Canada: 2004-2007.

摘要

We examined body condition and reproduction of harvested ringed seals (Phoca hispida) from a core, stable habitat (eastern Amundsen Gulf, Ulukhaktok, n=232) and from a non-core, dynamic habitat (west coast of Banks Island, Sachs Harbour, n=149) during the open water period, 2004-2007. Seals of all age classes generally had higher body condition indices (LMD index = length-mass-blubber depth) in corresponding years at the Sachs site compared with the Ulukhaktok site, but there were no temporal or statistical trends over the four years of study for adults or subadults. The body condition indices of pups in one year, 2005, was signficiantly lower at the Ulukhaktok site compared with Sachs Harbour, and this may be a reflection of reduced marine productivity in that year due to a particularly late spring break up of the sea ice (Harwood et al. 2012a). The open-water timing of this study, required to ensure an adequate sample size by coinciding with the months of peak seal hunting activity at Sachs Harbour, was not optimal timing for revealing trends in seal body condition. This is because seals harvested during the summer months have usually had several weeks to feed following spring break up (Smith 1987). This allows time to regain condition from the possible negative influences of a particularly harsh winter, or from fasting during spring (Smith 1987).