1. Introduction
The harp seal (Pagophilus groenlandicus) is a migratory
species of seal that shows seasonal movements between
breeding and feeding grounds. Three main distinct
populations of harp seals inhabit the Arctic and North Atlantic
oceans (Figure 1):
• Greenland Sea population
• White Sea population
• Northwest Atlantic population
Harp seals have been sighted off the coast of Norway (Figure
1), which is unusual as it is thought that they need pack ice to
whelp. The reason for this southward migration is unknown,
but it could be in search of a more sustainable environment.
Material and Methods
Samples for this study were collected from dead harp seals
along the coast of Norway. Sequence analysis of the
mitochondrial DNA control region was used to assess genetic
variability of these seals in comparison with other populations
of this species. Population genetic and phylogenetic analyses
were carried out using the software MEGA.
The origin and genetic variability of harp seals (Pagophilus groenlandicus)
off the coast of Norway
By Cameron Brown
Supervisor: Dr. Malgorzata Pilot
Fig. 1 – Map of harp seal populations and origin of samples
Fig. 2 – Simplified flowchart of
methods
Table 2 – Pairwise genetic distances
between three harp seal populations
Fig. 3 – Phylogenetic tree of harp seal
mtDNA control region sequences
White Sea
Baltic Sea
Norway
Results
Discussion and Conclusions
Data gathered in this study indicates
that the Norwegian seals most likely
originated from the White Sea, as
these two populations have similar
genetic composition and share
common haplotypes.
Migration from the Greenland Sea
could have occurred as well, but the
data required to test this is not
available.
The study shed some light on the
origin of the ancient extinct
population from the Baltic Sea. As all
three populations had similar genetic
composition, it could be suggested
that the founders of the Norwegian
and Baltic populations followed the
same migratory route from the White
Sea, with the Norwegian population
stopping further north as today's
temperatures are higher.
For future studies it would be
important to collect the data from
other harp seal populations, and
especially from Greenland. With more
data the origin of the harp seals
migrating to Norway can be
established with a higher confidence.
More data could also help answer the
question of where the ancient Baltic
population originated from.
Table 1 – Genetic variability and effective
population size of harp seal populations
This study is aimed to assess the origin and genetic variability of the Norwegian harp seals by analyzing mitochondrial DNA from tissue samples,
in comparison with other harp seal populations including an ancient population once present in the Baltic Sea