Use of molecular and isotopic signatures to inform foraging ecology and conservation needs for beaked whales in the NE Atlantic

Overview

Anthropogenic impacts on the marine environment, including chemical and noise pollution, fisheries interaction and climate change poses an active threat to marine species worldwide, and British large marine animals in particular (Evans and Waggitt 2020). Beaked whales are particularly sensitive to these threats but these cryptic, deep ocean species are highly challenging species to monitor. The Northeast Atlantic has become a global hotspot for beaked whale unusual mortality events (UME’S), with the largest ever beaked whale stranding occurring in 2018, and such UME’s appear to be increasing in both magnitude and frequency. Knowledge of beaked whale biology in the region, including distribution and habitat needs, remains poor, making the significance of these events difficult to fully evaluate. Warming ocean temperatures are likely to impact these animals health and ecological distributions through changes in available regional habitat and preferred prey (MacLeod et al. 2004; Leeney et al. 2008). As deep-diving predators, beaked whales are considered valuable indicators of marine ecosystem health on a larger scale, and their ecology and conservation is currently a topic of global interest (ASCOBANS 2021, Williamson et al. 2021).

Ocean warming is actively compressing available habitat for cold-adapted cetaceans (c.f., northern bottlenose whale [Hyperoodon ampullatus]), whereas cosmopolitan warmer-adapted species (Cuvier’s & Sowerby’s beaked whale [Ziphius cavirostris & Mesoplodon bidens]) are expanding their range. There is a clear increase over the past three decades in frequency of British warmer-water adapted beaked whale sightings and stranding events (ASCOBANS 2021). This trend is even more notable in northern waters, such as those located around Scotland. Interrogation of the strandings record shows an increase in incidence and magnitude of beaked whale strandings over the past decade (Brownlow 2019) possibly linked to changes in prey abundance and distribution due to climate change. Improved understanding of habitat use and feeding ecology in these species is therefore essential, given the cumulative impact from multiple anthropogenic stressors and the potential for overlap of cold-water and warmer-water adapted beaked whale species to increase interspecific competition.

Methodology

This project will draw on a range of tissue samples and stomach contents collected from necropsy examination of stranded beaked whales over the past 30 years (n>90). Analysis of a range of tissues from the same animal allows exploration in both recent and historic feeding ecology. These tissues have different metabolic rates to understand, with skin representing most recent reeding and muscle and bone capturing longer term feeding ecologies (Smith 2021).

This research will take advantage of state-of-the-art techniques in gas chromatography (GC) and mass spectrometry (MS) to characterize individual diagnostic whale-derived lipids – called ‘biomarkers’ – from skin and blubber samples in specimens recovered from British coastlines. Lipids will be extracted (via accelerated solvent extraction [ASE]) before isolation of biomarkers via ‘flash’ columns and liquid chromatography (LC) techniques. Target biomarkers will include metabolic compounds derived both from diet (e.g., omega-6 fatty acids) and from de novo synthesis (e.g., cholesterol) to maximize ecological insights. The scholar also will have opportunities to optimise analytical techniques to enable complementary (geo)chemical detection of further compounds, such as hormones viz. oestrogens, and bulk isotopic analyses

Project Timeline

Year 1

Literature review and techniques training. Processing, collection and initial analysis of archived beaked whale tissue samples from SMASS and NMS. Fieldwork with SMASS, incorporating attending marine strandings and training in undertaking strandings necropsy investigation and cetacean pathophysiology and beaked whale adaptive physiology.

Year 2

Posting with NMS (collaborative partner) on sample preparation and curation, and sample processing and analysis. Dissemination of initial findings at national conference and at relevent intergovernmental organisations annual meetings (ASCOBANS and IWC). Preparation and submission of first publication.

Year 3

Data analysis and synthesis with current literature. Dissemination of main study findings at international conference (Society for Marine Mammalogy) and preparation of second publication.

Year 3.5

Time devoted to thesis writing and publications.

Training
& Skills

This multidisciplinary project will equip the student with a range of general skills, including advanced ‘’omics’ and biomarker analysis, museum curation, marine strandings fieldwork, ‘big data’ analysis and translation of science for wider audiences.

Specific research skills will include:
• Gas chromatography-mass spectrometry (GC-MS) for advanced lipidomics/metabolomics
• Stable isotope analysis
• Marine mammal sampling training, including cetacean necropsy experience
• Sample preparation and curation experience within a dynamic
• Stakeholder engagement
• Biogeoscience statistics
• Conservation policy development
Facilities, equipment and expertise available within the institutions and supervisory team provide a combination of world-leading analytical, laboratory and field capability and technical support that ideally fits this PhD project maximising the expert training that will be available. The student will benefit from a network of collaborators at the Lyell Centre, Scottish Marine Animal Stranding Scheme (SMASS), National Environmental Isotope Facility (NEIF), National Museums of Scotland and Scottish Oceans Institute.

References & further reading

ASCOBANS (2021) Intersessional Working Group Report:,Overcoming Challenges to Protect Beaked Whales in the Northeast Atlantic https://www.ascobans.org/en/document/overcoming-challenges-protect-beaked-whales-northeast-atlantic-%E2%80%93-ascobans-intersessional

Brownlow A, et al 2019 Annual reports covering the marine animal strandings monitoring and investigation programme for Scotland, report to Marine Scotland https://osf.io/ks2v6/

Evans, P., Waggitt, J., 2020. Impacts of climate change on Marine Mammals, relevant to the
coastal and marine environment around the UK (MCCIP Science Review), Marine Climate
Change Impacts Partnership.

Leeney, R.H., et al., 2008. Spatio-temporal analysis of cetacean strandings and bycatch in a UK fisheries hotspot. Biodiversity and Conservation 17, 2323.

ASCOBANS (2021) Intersessional Working Group Report:,Overcoming Challenges to Protect Beaked Whales in the Northeast Atlantic https://www.ascobans.org/en/document/overcoming-challenges-protect-beaked-whales-northeast-atlantic-%E2%80%93-ascobans-intersessional

Brownlow A, et al 2019 Annual reports covering the marine animal strandings monitoring and investigation programme for Scotland, report to Marine Scotland https://osf.io/ks2v6/

Evans, P., Waggitt, J., 2020. Impacts of climate change on Marine Mammals, relevant to the
coastal and marine environment around the UK (MCCIP Science Review), Marine Climate
Change Impacts Partnership.

Leeney, R.H., et al., 2008. Spatio-temporal analysis of cetacean strandings and bycatch in a UK fisheries hotspot. Biodiversity and Conservation 17, 2323.

MacLeod, C.D., et al., 2004. Geographic and temporal variations in strandings of beaked whales (Ziphiidae) on the coasts of the UK and Republic of Ireland from 1800-2002. Journal of Cetacean Research and Management 6, 79.

Smith, K. J., et al. (2021). Stable isotope analysis of specimens of opportunity reveals ocean-scale site fidelity in an elusive whale species. Frontiers in Conservation Science, 2(May), 13. https://doi.org/10.3389/fcosc.2021.653766

Whiteman, J.P., et al., (2019). A guide to using compound-specific stable isotope analysis to study the fates of molecules in organisms and ecosystems. Diversity 11, 8.

Williamson, M.J., et al., (2021). Cetaceans as sentinels for informing climate change policy in UK waters. Marine Policy 131, 104634.

Further Information

Dr Andrew Brownlow (University of Glasgow)
E-mail: andrew.brownlow@glasgow.ac.uk
Mobile 07957347998
www.strandings.org
@strandings

Dr Clayton Magill (Lyell Centre, Heriot-Watt University): C.Magill@hw.ac.uk
Dr Sascha Hooker (University of St Andrews): sh43@st-andrews.ac.uk

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