The Lacs des Loups Marin harbour seal, Phoca vitulina mellonae Doutt 1942: Ecology of an isolated population

• Main Author: Smith, Richard John
• Other Authors: Lavigne, D.M.
• Format: Thesis
• Language: English
• Published: University of Guelph 1999
• Subjects: Lacs des Loups Marins harbour seal; Oceanic harbour seals; Hudson Bay; geographic isolation; haplotypic divergence; harbour seal; Phoca vitulina; Pusa hispida; ringed seal; Ungava peninsula
• Online Access: https://hdl.handle.net/10214/26098

Investigations were undertaken to determine to what extent the Lacs des Loups Marins harbour seal ('Phoca vitulina mellonae') is distinct and isolated from oceanic harbour seals. The population occurs in the area of Lacs des Loups Marins (Lower Seal Lakes) (56-57°N, 73-74°W), 160 km East of Hudson Bay, on the Ungava peninsula of northern Que?bec. Written references to the unique appearance and behaviour of this seal date back to 1818. The subspecies was described primarily on the basis of a characteristic morphology and presumed long-time geographic isolation from neighbouring oceanic harbour seals. A craniometric analysis of 'P. v. mellonae' confirmed that it is morphologically distinguishable from oceanic harbour seal subspecies in the Atlantic and Pacific. There was also evidence of behavioural differences: Pupping seems to take place substantially earlier (early May) than in other harbour seal populations at similar latitudes. An analysis of DNA sequences from the mitochondrial control region indicated that the Lacs des Loups Marins animals exhibit some haplotypic divergence from other harbour seals. Analyses of stable isotope ratios in hair and fatty acid signatures in blubber indicated that 'P. v. mellonae' feeds exclusively in freshwater. Monitoring of the movements of eight freshwater animals with satellite telemetry over portions of a two year period provided further evidence that not only are the seals resident within the Lacs des Loups Marins area, but that individual animals exhibit considerable site fidelity. The differentiation exhibited by 'P. v. mellonae' is similar to that demonstrated by isolated ringed seal populations in Lakes Saimaa, Finland ('Pusa hispida saimensis ') and Ladoga, Russia ('P. h. ladogensis'). The totality of the evidence collected provides support for the designation of the Lacs des Loups Marins seal as a distinct subspecies. The population warrants classification as an Evolutionarily Significant Unit. The information gathered on the range of 'P. v. mellonae' has ...