Large-scale genetic sampling by non-invasive methods is of vital importance for the conservation of vulnerable or elusive species. In the marine environment, non-invasive genetic sampling can provide a powerful alternative to conventional biopsies. We designed and implemented mucus swabbing for a free-ranging elasmobranch, thereby demonstrating the utility of this method in the field. We report the first attempt at mucus collection from 30 plankton-feeding basking sharks Cetorhinus maximus from 3 spatially distinct 'hotspots' in Irish waters. C. maximus DNA was successfully extracted and verified using DNA barcoding of the mitochondrial DNA cytochrome c oxidase 1 gene (99% sequence similarity) and basking shark species-specific multiplex PCRs derived from the nuclear ribosomal internal transcribed spacer 2 locus. Mitochondrial control region sequencing (1086 bp) showed that Irish samples were dominated by 2 haplotypes previously found to be globally distributed. Additionally, 1 novel haplotype was defined from western County Kerry. On-going genetic tagging will eventually provide more accurate estimates of global basking shark population structuring, abundance and behavioural ecology.
The fieldwork for this study in Ireland was funded by a Heritage Council Wildlife Grant (Grant Reference 16759). This work received funding from the
MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. Thanks to Margaret Wallace for technical support, and Michaél Cottrell, Darren Craig, Laura Kavanagh, Lucy Hunt, Nick Massett and Ian O’Connor for help with fieldwork and sample collection.
- Basking shark
- Cetorhinus maximus
- Genetic monitoring
- Mucus swabs
- Non-invasive sampling