IAP-24-099

Examining ecological shifts and impacts of adaptive divergence in response to geothermal habitats

Climate change poses a major threat to biodiversity, but some populations will undergo ecological shifts to persist with impacts on the supporting ecosystem. How this will occur is unknown but in some areas of geothermal warming provides unique opportunities to investigate the ecological impacts of a warmed habitat.

In Iceland’s geothermally warmed habitats, we have discovered several populations of threespine stickleback. This has driven adaptive divergence in metabolism, morphology, and behaviour (Pilakouta et al 2020, 2023). However, evidence also suggests that ecological differences in diet occur. This could drive much of the adaptive divergence observed, while also impacting the broader community.

This project will look directly at the dietary changes that occur in these populations to better understand the ecological drivers of thermally-driven adaptive change. To achieve this the project will address three main aims:

1. Analysis of long-term dietary variation between populations from geothermal and ambient habitats (across multiple locations)
2. Assess ontogenetic variation in diet to determine at what life stage ecological divergence occurs
3. Tests of heritable divergence in diet preferences, performance, and bioenergetic partitioning through the use of lab-rearing and mesocosm experiments

The project will involve field work in Iceland during both the winter and summer, lab-rearing stickleback experiments at Glasgow, and mesocosm experiments in Lancaster. Lab skills will involve measurement and analysis of stomach contents, fatty acids and stable isotopes and metabolic rates. Phenotyping skills such as morphometrics, high-speed camera use and kinematic analysis will be used to connect ecology to phenotypic variation.

Year 1

– Field work in Iceland during the summer and winter
– Analysis of growth rates, stomach contents, stable isotopes and fatty acids.
– Feeding trials on fish using high-speed cameras, kinematic analysis

Year 2

– Test heritable and plastic contributions to functional divergence using lab rearing
– Mesocosms experiments
– Attendance at a national conference (e.g. BES)

Year 3

– Analysis of mesocosm experiment data (stomach contents, stable isotopes and fatty acids, and assessment of the mesocosm communities in response fish from different backgrounds.
– Attendance at an international conference (e.g. ESEB)

Year 3.5

– Final analysis and thesis writing/submission

The student will gain a wide range of skills that will make them competitive for employment within industry or academia. They will gain fundamental skills in field-sampling, animal husbandry, statistics and experimental design. More specifically they will become well-versed in the analysis and obtainment of ecological data from individuals, stable isotopes, stomach contents and fatty acids. They will be trained to identify anatomical variation, and assess its function. Finally, the student will gain an understanding of community ecology.