Genetic structure and diversity of South Africa's inshore Bryde's whale (Balaenoptera edeni brydei, Olsen 1913) population

• Other Authors: Bloomer, Paulette, Vermeulen, Els, Paynee, Dominique Kelsi
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Pretoria 2023
• Subjects: UCTD; Zoology; Population Genetics; baleen whale
• Online Access: https://repository.up.ac.za/handle/2263/89406; https://doi.org/10.25403/UPresearchdata.22067123

Dissertation (MSc (Zoology))--University of Pretoria, 2022. South Africa’s inshore Bryde’s whale (Balaenoptera edeni brydei) is the largest, resident baleen whale species occurring in our coastal waters. However, due to being one of the most elusive and shy marine mammals, there are significant gaps in knowledge relating to their phylogeny, ecology, and demography. The few studies done on this population provided important, broadscale information but also highlighted the more detailed research needed to improve and develop the understanding of South Africa’s inshore Bryde’s whales. It is generally accepted that these whales form a small population (< 1,000 mature individuals) that shows a restricted coastal distribution along the coastline of South Africa. Their movements along the coast are largely dictated by the movements of their main food sources, sardine (Sardinops sagax) and anchovy (Engraulis capensis). However, their population structure, movement patterns, and habitat use across the diverse oceanic system surrounding South Africa, as well as the level of genetic diversity remained unclear. Within the broader, evolutionary perspective the connectivity of the inshore population to other Bryde’s whale populations worldwide is unknown. ii This dissertation uses conservation genetic approaches combined with photo-identification methods to build our understanding of South Africa’s inshore Bryde’s whale population in two main areas. Microsatellite and mitochondrial DNA (mtDNA) markers were used to detect any evidence of population structure and connectivity while assessing current levels of genetic diversity on both local and global scales. Photo-identification data was then used to assess the movement patterns of individuals and formalize a national catalogue for the population. Genetic results show that these whales form one population with low, but significant, levels of genetic differentiation between the west and south coast of South Africa. Neutral nuclear genetic diversity was high which may be ...