The influence of Holocene sea-ice variability on Arctic biota: using the past to predict the future

Lead Research Organisation: University of Oxford


Sea ice provides an important seasonal or perennial habitat and dispersal corridor for many Arctic species and acts as a major geographic barrier for others; it therefore influences the distributions, gene flow, and species interactions of marine and terrestrial biota. The Arctic Ocean is predicted to become seasonally ice-free this century as a result of climate change. The ecological and evolutionary consequences of this change remain poorly understood, although species with a high reliance on sea ice to complete their life histories are likely to be particularly vulnerable. Our ability to quantify the impacts of sea ice loss is hampered by our limited understanding of how species respond to long-term spatial and temporal variation in sea ice. This is due to a shortage of historic and modern observational data for many species, as well as sparse data on the natural variability of sea ice since the Last Glacial Maximum, although high-resolution sea ice reconstructions are emerging. Another challenge is to improve attribution of sea ice as the primary driver of species dynamics, as many associations remain speculative due to lack of appropriate sea ice and/or biotic data, in many cases not even using sea ice data at all.
This project aims to advance predictions of impacts of current sea ice loss by improving our understanding of the long-term interactions between sea ice and Arctic species, specifically: how sea ice variability influenced Arctic biota during the Holocene (11,700 years - present). The three main areas of study are:
i. What is the spatiotemporal history of selected ice-associated species during the Holocene?
ii. What is the relationship between sea ice and Arctic species dynamics in the Holocene?
iii. How does sea ice continue to influence plant dispersal in the Arctic, and how do modern plant dispersal pathways compare with reconstructed dispersal pathways?
A pre-analysis systematic review of which species are most dependent on sea ice, and which are therefore most likely to be at risk from sea ice loss, will help inform selection of focal species and help generate hypotheses. The project will use emerging high-resolution driftwood-based reconstructions of Holocene Arctic sea ice (Hole & Macias-Fauria, 2017) which will give detailed information on the natural variability of sea ice dynamics. For question (i), ancient DNA from fossils and modern molecular data will be compiled to reconstruct and model species dynamics using: population genetic analysis (demographic change, population connectivity, and genetic diversity) and species distribution modelling (range shifts and dispersal events). For (iii) the project will combine reconstructions of sea ice and species dynamics to assess causality from the spatiotemporal patterns of covariability. The analysis will also account for other possible sources of variation in species dynamics, for example: other aspects of climate, geography, and biotic interactions. In addition, species dynamics may also be impacted by increasing human-driven pressures in the Arctic, as a result of its increasing accessibility. Question (iv) will entail fieldwork analysing plant material that is deposited by coastal sea ice on Svalbard beaches. This will involve collection, identification, and viability-testing of propagules, identification of possible source regions, and an analysis of whether modern dispersal pathways agree with the spatiotemporal histories of the study plants. There is potential to develop a citizen-science project in collaboration with the Environment Department of the Svalbard Governor.
The results from this project will reveal the extent to which sea-ice has historically influenced Arctic biota, and give insights into potential ecological and evolutionary responses to current sea ice loss; thereby enabling more accurate predictions of the impacts of climate change in the Arctic.


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Studentship Projects

Project Reference Relationship Related To Start End Student Name
NE/W502728/1 01/04/2021 31/03/2022
1929306 Studentship NE/W502728/1 01/10/2017 30/06/2022 Maria Dance
Description Collaboration with Mackay Lab 
Organisation University of Oxford
Department Department of Plant Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution I have provided help to other PhD students in the lab when I could, and I also presented my research to the lab group during a lab group meeting. My supervisor has contributed £2000 in bench fees and purchase of specific consumables.
Collaborator Contribution The partners provided lab access, bench space, and consumables for my DNA extractions, and general assistance from other PhD students in the lab. The estimate of the in-kind contributions is based on general consumables and use of equipment that I was not charged for.
Impact Data from collaboration currently in preparation at sequencing company (expected April 2022)
Start Year 2021
Description Collaboration with University of Oslo Museum of Natural History for access to samples 
Organisation University of Oslo
Country Norway 
Sector Academic/University 
PI Contribution I agreed to abide by the conditions of the formal loan agreeement made between myself and the museum, including attributing data source, publishing sequenced data on a web database, and sharing any publications arising from utlisation of the material with the museum.
Collaborator Contribution The Museum provided upon request, material from 42 Dwarf birch specimens held at the herbarium. I extracted DNA from these samples. These samples fill geographical gaps in mine and Marc's dwarf birch dataset.
Impact Sequence data currently under construction (expected April 2022)
Start Year 2021
Description Guest PhD student at the University Centre in Svalbard 
Organisation University Centre in Svalbard
Country Norway 
Sector Academic/University 
PI Contribution I have conducted analysis of my PhD data in the lab at UNIS. I have paid bench fees and for the consumables I used using my research award. During a field cruise in August 2020 I will collect samples for UNIS.
Collaborator Contribution I am formally recognised as a guest PhD student at UNIS. This means that I can access their logistical services for fieldwork free of charge, and access their lab space and other facilities such as accommodation. For my lab work my collaborator contributed expertise in molecular biology and genetic lab techniques and analyses, and taught me these new skills. My collaborators have also enabled my participation in a field cruise in August 2020, where I will collect samples for UNIS and also be able to collect samples for my PhD.
Impact There have been no outputs as of yet as I am still conducting/have yet to conduct the fieldwork and data analysis associated with this collaboration.
Start Year 2019
Description Scientific lecture on tourist ship 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Location: Svalbard. Date: August 2021. As part of a wider UNIS-Hurtigruten outreach programme (Science on B(o)ard), I gave a short and accessible presentation to guests on board MS Bard, a tourist excursion ship. The topic was the impacts of climate change and sea ice loss on Arctic species
Year(s) Of Engagement Activity 2021