Assessment of mitochondrial DNA structuring and nursery use in the North Atlantic right whale (Eubalaena glacialis)

The North Atlantic right whale (Eubalaena glacialis) inhabits five areas al ong the east coast of North America at different times of the year. During 17 years of field observations, it has been found that only 59% of the newb orn calves are brought to the Bay of Fundy nursery area. To examine whether this is because of population structuring, the mitochondrial DNA (mtDNA) c ontrol region haplotypes were determined for 269 individuals. Seven polymor phic sites were found to define five haplotypes. Calves were divided into t wo groups based on whether or not they were brought to the Bay of Fundy nur sery. Significant genetic structuring of mitochondrial haplotypes was found between these groups (p = 0.002). Mothers that have had more than three ca lves demonstrated significant fidelity (p = 0.005) to the Bay of Fundy, sug gesting that philopatry is the basis for the genetic structuring. Although this study clearly identifies the existence of two subpopulations and an al ternative nursery area(s), the location(s) of the alternative area(s) is un clear and remains an important issue for the conservation of the species.