Setting the tempo for Halavi guitarfish behavioural rhythms
The Al Wajh lagoon in the northern Red Sea is believed to serve as a vital nursery and refuge for Critically Endangered Halavi guitarfish, yet almost nothing is known about how they use the habitat or respond to environmental pressures. The lagoon experiences more extreme temperature fluctuations than the rest of the Red Sea and is being developed as part of Saudi Arabia’s ecotourism industry, which will remove critical habitats. Eloise wants to understand how temperature extremes and coastal development affect the health, behaviour and reproduction of these rays. She is collecting data for metabolic and hormonal markers, providing a robust foundation for conservation planning.
Eloise Richardson
I began my scientific career studying the ecological impacts of the Eurasian beaver in Scotland, as part of my Bachelor’s (Hons) thesis in animal science. After graduating I travelled the Americas, a trip that ultimately steered me towards marine science. An internship in the Bahamas catapulted me into the world of shark science, where I spent more than three years managing and working in a remote field station. Living on a small island, I loved the hands-on nature of the field work and developed a deep interest in the movements and physiology of elasmobranchs.
This experience shaped...
Kaitlyn O’Toole
My passion for the marine environment began at a young age, growing up collecting all sorts of critters my mother didn’t approve of along the shore of the Long Island Sound in New York. I spent my summers in high school working on a scallop restoration programme in one of the local bays and was lucky enough to see at first hand how successful restoration and a sustainably managed fishery were possible. Happy scallops, happy fishers, happy stomachs. I went on to receive my undergraduate degree in marine science, when my love for the marine environment was enhanced...
Biochemical cues setting the tempo for Guitarfish behavioral rhythms
To further biological and ecological understanding of the Critically Endangered Halavi guitarfish by analysing blood metabolites and hormone concentrations across life stages, seasons and habitats. This research will reveal how environmental stressors such as temperature and coastal development may influence health, behaviour and reproductive cycles.
The Halavi guitarfish is threatened by fishing and rapid coastal development in the Red Sea, but little is known about its biology or how it responds to environmental stressors. This project provides the first in-situ data collection for metabolic and hormonal markers in a Rhinopristiform species at this scale and lays a robust foundation for conservation planning in line with both regional biodiversity goals and global efforts.
Shark-like rays, known as rhino rays (Order: Rhinopristiformes), are one of the most threatened groups of marine animals, primarily due to fishing pressure. Conservation efforts are especially challenging in regions like the Red Sea, where little is known about their biology, ecology or population health. The Halavi guitarfish Glaucostegus halavi, a Critically Endangered rhino ray, is endemic to the north-western Indian Ocean and faces population decline from unmanaged fishing.
The Al Wajh Lagoon in the northern Red Sea is believed to serve as a vital nursery and refuge for Halavi guitarfish, yet almost nothing is known about how these animals use the habitat or how they respond to environmental pressures. This is particularly relevant here as the lagoon experiences more extreme temperature fluctuations than the rest of the Red Sea and is being developed as part of Saudi Arabia’s ecotourism industry, which will result in the removal of critical habitats.
This project builds on extensive field work conducted from 2022 to 2025, during which more than 200 Halavi guitarfish were sampled across life stages and seasons. By analysing blood metabolites and hormone levels from these samples, we aim to understand how environmental stressors, such as temperature variation and coastal development, may influence their health, growth and reproduction. These physiological insights, combined with ongoing research into genetics, heavy metal contaminants and diet, will provide a comprehensive picture of this population.
Ultimately, this work will deliver the first in-situ physiological data for this species, and any other rhino ray, at this scale, informing targeted conservation action, spatial planning and sustainable development strategies. The findings will guide local management to protect critical habitats and contribute globally to the conservation of rhino rays and, by extension, other vulnerable elasmobranchs.
The primary aim of this project is to understand how environmental factors such as temperature extremes and coastal development affect the health, behaviour and reproduction of the Critically Endangered Halavi guitarfish. By building a physiological baseline for this species, we can better predict how it – and, by extension, other elasmobranchs – will respond to a changing environment. Objectives include:
- To analyse blood metabolites and hormones across life stages, sexes, seasons and habitats to assess health, growth and reproductive status.
- To investigate how environmental stressors influence these physiological responses.
- To combine physiological data with information on genetics, pollutants and diet to create a comprehensive understanding of the Al Wajh population.
- To use our findings to identify critical habitats and therefore inform spatial planning, sustainable development and conservation policies in the Red Sea.