Abstract:
We are currently witnessing significant climate changes in high latitude ecosystems including
many areas of the Arctic. Many high latitude species, like harp seals (Pagophilus groenlandicus), will be
affected and their populations forced to adapt to changing habitats. The overall fitness and genetic
diversity of the population will affect how quickly a population can adapt. This study used microsatellite
markers to determine and compare heterozygosity and fitness between stranded and by-caught harp
seals along the east coast of the United States. Our study found there is no significant difference in
fitness (d²) between these two groups and that the overall fitness of the population is high. We found
that for most markers, stranded seals had a higher mean d² and that only one marker showed significant
differences between the two groups. Both groups had equal heterozygosities, supporting the idea that
the seals come from the same population. These results demonstrate that the increasing strandings and
entanglements are due to other factors than fitness or genetic diversity. Climate change is playing a
large in role in the survival and adaptation of these species. When compared to ice cover data, there is a
correlation between years with light ice cover and high strandings. Future studies should investigate this
correlation to see if climate is the driving force behind increases in sightings of harp seals within the
United States. Harp seals are a useful indicator species for the changing Arctic climate system and it will
be important for managers to understand what they can do to conserve the species and resources of the
Arctic ecosystem.
