Molecular ecology of marine mammals

• Main Author: Olsen, Morten Tange
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Institutionen för genetik, mikrobiologi och toxikologi 2012
• Subjects: Marine mammals; molecular ecology; life history; environmental change; phenotypic plasticity; SNPs; telomeres; Genetics; Genetik; Arctic; Balaenoptera physalus; Fin whale; Megaptera novaeangliae; North Atlantic; Pusa hispida; ringed seal; Sea ice
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-71166

Marine mammals comprise a paraphyletic group of species whose current abundance and distribution has been greatly shaped by past environmental changes and anthropogenic impacts. This thesis describes molecular ecological approaches to answer questions regarding habitat requirements, genetic differentiation, and life-history trade-offs in three species of marine mammals. The annual sea-ice dynamics of the Arctic may have large effects on the abundance and distribution of Arctic species such as the pagophilic ringed seal (Pusa hispida). Paper I describes and applies a simple molecular method for isolating and characterizing a relatively large set of single nucleotide polymorphisms (SNPs) in the ringed seal. These SNPs have been genotyped in a yet-to-be-analysed dataset which will form the basis in an assessment of the micro-evolutionary effects of annual sea-ice dynamics on ringed seal. Current management efforts directed towards the North Atlantic fin whale (Balaenoptera physalus) are hampered by an unclear understanding of population structure. Paper II investigates the DNA basis for the high levels of genetic differentiation that have been reported in allozyme studies of the North Atlantic fin whale. We find that additional processes (at the organismal level) may have contributed to shaping the phenotype of the underlying allozyme variation. Telomeres may potentially serve as markers for determining the chronological and biological age of animals where other means of inference is difficult. Paper III describes the application and evaluation of four qPCR assays for telomere length estimation in humpback whales (Megaptera novaeangliae), finding that reliable telomere length estimates require extensive quality control. Paper IV applies the best performing qPCR assay to test whether telomeres may provide a method for genetic determination of chronological age in whales and concludes that the biological and experimental variation in telomere length estimates is too large to determine age with sufficient resolution. ...