Characterization of Population Structure in Northern Bottlenose Whales (Hyperoodon ampullatus) in the North Atlantic from an Analysis of Microsatellite Data

• Main Author: Feyrer, Laura
• Format: Text
• Language: unknown
• Published: Open Science Framework 2022
• Subjects: Jan Mayen; Newfoundland; Davis Strait; hyperoodon ampullatus; Iceland; Labrador Sea; North Atlantic; Northern bottlenose whale; Northwest Atlantic
• Online Access: https://dx.doi.org/10.17605/osf.io/97avs; https://osf.io/97avs/

The objective of this analysis was to better understand northern bottlenose whale (NBW, Hyperoodon ampullatus) population structure and viability across the North Atlantic using 60 contemporary tissue specimens not available during previous genetic analyses (Feyrer et al. 2019). Tissue samples were recently collected from the Scotian Shelf, the Davis Strait – Labrador Sea, Jan Mayen near Iceland, and from a stranding in southern Newfoundland. This report focuses on results from an analysis of microsatellite data, as mitogenome assemblies were incomplete due to experimental difficulties. Among the available samples, a total of 55 unique individuals were identified by microsatellites, expanding the current genetic dataset of NBW specimens to 218 individuals collected between 1967-2019. Population structure analyses of all samples were consistent with previous reports of site fidelity, where individuals resampled at different time periods were found to have remained in the same geographic region. We detected a low number of unique microsatellite alleles in contemporary samples (2017-2019, n = 29) from the Davis Strait – Labrador Sea relative to historical samples (1971, n = 78), consistent with population reductions due to harvesting and genetic drift. In contrast, more unique alleles were detected in contemporary samples from Iceland (2014-2016, n = 26) than in historical samples from 1967 (n = 7), but this may be due to the difference in sample sizes. Analyses of population structure supported three distinct genetic groups residing in separate geographic locations: the Scotian Shelf, the northwest Atlantic (Davis Strait – Labrador Sea) and West Iceland (1967), and East Iceland (2014-2016). The differentiation of contemporary Eastern Icelandic samples from other regions has not yet been reported in the literature due to the low number of modern samples available from this region, highlighting the importance of adequate sample sizes and distribution to detect subtle population structure in NBW using microsatellites.