Combined effects of climate change and metal exposure to physiological adaptation in early life stages of Christmas Island land crabs in wetland ecosystems

This project is part of the NERC-funded Centre for Doctoral Training, ECOWILD. For more details, and for a full list of projects offered under this programme, please visit: https://ecowild.site.hw.ac.uk/

Christmas Island is a unique and vulnerable habitat dominated by evolutionary expansion in land crabs exploiting the absence of predatory threats common on other tropical island habitats. Two of the wetland systems on Christmas Island are internally recognised for their importance through the Ramsar Convention on Wetlands, the mangroves at Hosnies Springs, and The Dales wetland system. Phosphate mining was established on the island over a century ago, and open cast mining areas and phosphate stockpiles are scattered across the island and provide a potential source of contaminants such as cadmium and other metals to the wider island environment.

Understanding complex multi-stressor conditions in light of climate change and increasing pollution pressure on crab reproduction and early life stages will provide valuable insight into their vulnerability or resilience to future climate conditions and deepen our understanding into the mechanisms of their adaptive success at a genetic and physiological level. The project will be a combined approach of multistressor challenges in a controlled environment, working with a model lab-reared tropical freshwater crab, a field campaign to Christmas Island, and application of science in policy and conservation. Use of a model lab system will enable training and method development in embryophenomics and molecular mechanisms of adaptive responses to combined stressors (e.g. cadmium and elevated temperatures). The field campaign will focus on Hosnies Springs and The Dales. Water, sediment, and biota (crabs) samples will be collected for contaminant profiling. Sampling will be carried out in the rainy season during the yearly crab migration from various pristine and potentially contaminated sites. Parks Australia will act as stakeholder and provide data on contaminant profiles of selected island sites. Pre-release fertilised embryos will be collected and exposed to an acute multistressor challenge before analysis by embryophenomics, and tissue will be collected for molecular and genetic methods.

Protection and understanding of wetlands under multistressor conditions is at the heart of the ECOWILD CDT and this project is built around its aims and goals. This project addresses two of the five main goals of the program. Firstly, it directly assesses multiple stressor effects on individual species at wetland sites on Christmas Island. Secondly, generating conservation policy relevant science by working within a protected area to directly influence monitoring and management and partnering with JNCC who are UK Focal Centre for the Ramsar Scientific and Technical Review Panel to consider translatability for island nations. JNCC will act as CASE Partner and stakeholder, with Isabella Gosetto as their lead named person. They will provide CASE contribution to the RTSG and a 3-month placement within their Environmental Pollution team. Parks Australia will join as an external stakeholder, engaging in field planning and project meetings as needed. Additionally, in-kind support will include on-island costs of accommodation, field support, access to protected sites, and necessary permits. Support and engagement has been agreed with Ramsar directly.

Supervisory team: Dr Helena Reinardy is a molecular and genetic ecotoxicologist, with broad experience in multistressor experiments (e.g. metals, temperature challenge) and effects analysis in a range of vertebrate and invertebrate aquatic species. Her specialism is in genetic toxicology of environmental stressors, and she will lead on supporting the DNA damage response systems and metal detoxification. Genotoxicology and gene expression methodology will be based in her laboratory at SAMS, and she will lead the supervisory team and act as Director of Studies.

Prof Alistair Boxall is an environmental chemist with extensive experience in understanding the fate, occurrence and accumulation of chemical contaminants in the natural environment. Alistair will provide expertise on the analytical and environmental chemistry aspects of the project.

Dr Lucy Turner is an expert in land crab ecophysiology and has led and conducted fieldwork on Christmas Island since 2007 (six previous field campaigns). She has expertise and will provide training in the ecophysiological including developmental (embryophenomics) techniques needed for this project. Her group in Plymouth holds stocks of lab-reared freshwater land crabs Geosesarma sp. which will be used as the lab model organism enabling the perfection of experimental design and techniques before any fieldwork. She will be a co-supervisor.

Essential skills include: molecular biology and/or physiological laboratory experience, experimental aquatic biology, field work, and data analyses.

We recognise that not every talented researcher will have had the same opportunities to advance their careers. We therefore will account for any particular circumstances that applicants disclose (e.g. parental leave, caring duties, part-time jobs to support studies, disabilities etc.) to ensure an inclusive and fair recruitment process.

For more information on how to apply, please visit the ECOWILD website: https://ecowild.site.hw.ac.uk/how-to-apply/