Abstract
Migratory movements in response to seasonal resources often influence population structure and dynamics. Yet in mobile marine predators, population genetic consequences of such repetitious behaviour remain inaccessible without comprehensive sampling strategies. Temporal genetic sampling of seasonally recurring aggregations of planktivorous basking sharks, Cetorhinus maximus, in the Northeast Atlantic (NEA) affords an opportunity to resolve individual re-encounters at key sites with population connectivity and patterns of relatedness. Genetic tagging (19 microsatellites) revealed 18% of re-sampled individuals in the NEA demonstrated inter/multi-annual site-specific re-encounters. High genetic connectivity and migration between aggregation sites indicate the Irish Sea as an important movement corridor, with a contemporary effective population estimate (Ne) of 382 (CI = 241-830). We contrast the prevailing view of high gene flow across oceanic regions with evidence of population structure within the NEA, with early-season sharks off southwest Ireland possibly representing genetically distinct migrants. Finally, we found basking sharks surfacing together in the NEA are on average more related than expected by chance, suggesting a genetic consequence of, or a potential mechanism maintaining, site-specific re-encounters. Long-term temporal genetic monitoring is paramount in determining future viability of cosmopolitan marine species, identifying genetic units for conservation management, and for understanding aggregation structure and dynamics.
| Original language | English |
|---|---|
| Article number | 1661 |
| Number of pages | 17 |
| Journal | Scientific Reports |
| Volume | 10 |
| DOIs | |
| Publication status | Published - 3 Feb 2020 |
Bibliographical note
We thank everyone involved in sample collection for their time, expertise and dedication including: Innes Henderson and John McCann; Kevin Robinson and his team from the Cetacean Research and Rescue Unit; Michaél Cottrell, Darren Craig, Laura Kavanagh, Lucy Hunt, Nick Massett and Ian O’Connor; Andrew Brownlow and Nick Davison from the SRUC Wildlife Unit, Inverness; Colin and Louise Speedie of Wave Action and Sealife Surveys (Tobermory); and volunteers from the Manx Basking Shark Watch. Thanks to Margaret Wallace and Giulia Denaro for technical support and Robin Waples as well as Marius Wenzel for data analysis support. JH and GH are grateful to the Manx Wildlife Trust. SB acknowledges funding for fieldwork from the Heritage Council Wildlife Grant (grant reference 16759 and R00342) and the Inishowen Development Partnership. EdeS is grateful to the Prince Albert II of Monaco Foundation for funding Mediterranean fieldwork. DWS was supported by a Marine Biological Association Senior Research Fellowship and acknowledges funding from the Good Gifts Catalogues for sample collection by JH and GH. LRN and CSJ gratefully acknowledge funded access to the Natural Environment Research Council (NERC) Biomolecular Analysis Facility at the University of Sheffield (grant reference NBAF723), as well as funds from Dept. of Environment, Food and Rural Affairs (DEFRA) contract CR0288, and Scottish Natural Heritage (SNH). LL was supported by a studentship from the MASTS (The Marine Alliance for Science and Technology for Scotland) pooling initiative and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Keywords
- EFFECTIVE POPULATION-SIZE
- MARINE PREDATOR MOVEMENTS
- BASKING SHARKS
- PAIRWISE RELATEDNESS
- R-PACKAGE
- CETORHINUS-MAXIMUS
- FORAGING BEHAVIOR
- RHINCODON-TYPUS
- SOCIAL-BEHAVIOR
- WHALE SHARKS
Access to Document
- Lieber_etal_SciRep_Spatio-temporal_VOR
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