ACCE+ DLA programme: Resilience and adaptive potential of sea turtle populations to climate change

Background

Climate change is altering the world’s ecosystems at an unprecedented rate and understanding the resilience of species and populations to withstand this change is critical to inform and prioritise conservation efforts. Like many reptiles, sea turtles exhibit temperature-dependent sex determination (TSD): incubation duration, hatch success, hatchling sex and fitness are all influenced by ambient temperatures. Through reduced hatch success and female-skewed sex ratios, climate change is thus likely to elicit significant population effects. Knowledge gaps remain however in the adaptive significance of TSD, how thermal microclimates drive variation in primary sex ratios, how these translate into adult sex ratios, and the potential for range shifts as new areas of suitable nesting habitat become available. This study will address these gaps, through a combination of field, lab and modelling approaches, focussing on the loggerhead sea turtle, Caretta caretta population of Cabo Verde, West Africa.

Objectives

1. Use available data on male and female breeding intervals to estimate optimal adult sex ratios for population viability
2. Assess spatiotemporal variation in hatchling sex ratios to identify adaptive potential of the population to mitigate future temperature increases and female bias
3. Investigate patterns of multiple paternity in the rookery to assess breeding sex ratios and potential male scarcity
4. Develop an individual-based model of hatchling dispersal from the Cabo Verde population to determine possibility of range expansion

Novelty

Reptiles are uniquely vulnerable to climate change and the adaptive significance of TSD remains poorly understood. The project will address existing gaps in our knowledge to broaden the conceptual understanding of TSD under climate change, whilst contributing directly to conservation management of sea turtles more broadly. This multidisciplinary project combines field, laboratory and modelling techniques and will allow the student to develop a well-rounded skillset for future employment. The loggerhead turtle population in Cabo Verde has in recent years shown dramatic increases in nesting densities and is one of the largest in the world, offering an ideal study system for prospective students to explore these concepts. The project will build upon unique multiyear datasets provided by project partners.

Timeliness

Climate change is a rapidly increasing driver for biodiversity loss in addition to habitat alteration/degradation and exploitation. Global temperature increases will influence all life history stages of sea turtles, a group of ecological, cultural, and socioeconomic importance. The outputs of this project will address key research priorities and be incorporated into conservation management.

Whilst this project has the opportunity for overseas fieldwork, we will welcome and consider applications from candidates of all backgrounds, abilities and circumstances. Support will be provided throughout the project.

How to Apply

Please see the ACCE website for all details of how to apply to the programme at each ACCE+ institution: https://accedtp.ac.uk/how-to-apply/. 

All applicants to ACCE+ must complete the ACCE+ personal statement proforma. This is instead of a personal/supporting statement or cover letter. The proforma is designed to standardise this part of the application to minimise the difference between those who are given support and those who are not. Candidates should also submit a CV and the contact details of two referees.

Part-Time Study Options

All ACCE+ PhDs are available as part time or full time, with part time being a minimum of 50% of full time. Please discuss potential part time arrangements with the primary supervisor before applying to the programme. 

Project CASE Status

This project is not a CASE project. 

Candidate webinar

The project primary supervisor will hold a candidate Zoom webinar in December 2024 to discuss the project with interested candidates. Please register here if you would like to join!