Genetic variation of the St. Lawrence beluga whale population assessed by DNA fingerprinting

Authors


  • The research that led to this paper is part of a larger ongoing study that is examining the population and conservation genetics of beluga whales in the waters of North America. N. J. Patenaude was an MSc student, J. S. Quinn was an Assistant Professor (PT), P. Beland was Senior Scientist, M. Kingsley was Section Head of Marine Mammal Research and B. N. White was a Professor and Chair of the Biology Department when this work was done. Funding was provided by the Natural Sciences and Engineering Research Council of Canada and the Department of Fisheries and Oceans through the St. Lawrence Action Plan. N.J.P. was supported by a Northern Studies Training Programme grant. St. Lawrence samples were obtained under a grant from the Wildlife Toxicology Fund, Canada.

Department of Biology, McMaster University, Hamilton, Ont., Canada L8S 4K1 Tel. (905) 525–9140 ext 24400; fax (905) 522–6066; E-mail whitebn@mcmaster.ca.

Abstract

Recent surveys suggest that the endangered St. Lawrence beluga (Delphinapterus leucas) population is not recovering significantly despite 20 years of protection. Dead individuals that have been autopsied show high levels of tumours and infections. This situation could be a result of pollution, loss of genetic variation, inbreeding depression or a combination of these factors. Analyses of DNA fingerprints from St. Lawrence belugas with three minisatellite probes (Jeffreys 33.6, 33.15 and M13) indicate a reduced level of genetic variation compared to Beaufort Sea animals. The average band-sharing between individuals of the St. Lawrence beluga population for the three probes (0.534, 0.573 and 0.478, respectively) was significantly higher than that of the Beaufort Sea beluga population (0.343, 0.424, 0.314, respectively). Higher levels of mean allele frequency in the St. Lawrence belugas (0.33 vs. 0.21) suggest that this population is composed of individuals which are related. Inbreeding depression could therefore be a factor in the lack of recovery of the St. Lawrence beluga population.

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