STUDENTS

 Over the years, the Manta Trust has supported a number of students pursuing a research career in manta and devil ray ecology, fisheries, and conservation. The support provided by the charity has come in the form of financial support, access to, and support in field locations, as well as mentoring and academic support.

CURRENT STUDENTS

There are currently a number of research students around the world pursuing a PhD or MSc in marine biology and conservation through the Manta Trust. Scroll down to read about some of the current projects the Manta Trust is supporting.

 CALVIN BEALE

PhD Candidate at Murdoch University, Australia

Movement Ecology of Oceanic manta rays (Mobula birostris)

The movement ecology of oceanic manta rays remains a mystery as most studies focus on the generally more easily encountered reef manta rays (Mobula alfredi). Oceanic manta rays are more pelagic in nature than reef manta rays, often preferring shelf-edge or deeper water habitats to coastal reefs. This makes them more difficult to interact with and study, so there is a dearth of information surrounding their movements, diving, and feeding behaviours. This project aims to investigate the movements or migratory patterns, diving behaviours, and the causes and consequences of extreme diving in oceanic manta rays. This research is mainly focused in the Raja Ampat area of eastern Indonesia but also collaborates with studies done in New Zealand and Peru. We are using pop-up satellite archival tags and fastloc GPS tags to record location, temperature, and depth profiles over six-to-twelve-month deployment periods to answer the questions of where, when, why and how!

We hope that with an increased knowledge of this species’ movement ecology it will be easier for management bodies globally to be able to make informed decisions to protect the species. These could include spatial or temporal restrictions within key aggregations sites or birthing grounds, restrictions in the use of certain types of fishing gear, and better management of visitation to cleaning stations by tourism operators.

 RACHEL NEWSOME

PhD Candidate at Murdoch University, Australia

Activity and energetics of reef manta rays (Mobula alfredi) in contrasting seascapes

This project aims to compare the movement, habitat use and energetics of reef manta rays from two differing seascapes, D’Arros Island and St Joseph Atoll in the Seychelle Islands and Ningaloo World Heritage Area, a fringing reef system in Western Australia. These sites not only offer an exciting experimental design through the comparison of manta ray behavioural ecology in contrasting seascapes but will also allow us to determine anthropogenic impact on reef manta rays by comparing the Seychelles (relatively ‘undisturbed’) with putative high tourism impact at Ningaloo. We will employ combined cutting-edge animal attached-tagging technologies comprised of movement and environmental sensors for the first time to determine the behaviour, habitat use and energetics of reef manta rays and the mechanisms that drive these movements. This project will provide insight into the spatial, temporal, environmental and anthropogenic mechanisms driving habitat selection and movement and behavioural patterns of reef manta rays.

 HANNAH MOLONEY

PhD candidate at the University of the Sunshine Coast, Australia

Oceanographic drivers of manta ray feeding ecology and behaviour

Hanifaru Bay in the Maldives hosts an ephemeral hotspot to the world’s largest feeding aggregation of manta rays. Hundreds of manta rays gather to feast on nutrient-rich zooplankton often adopting coordinated feeding strategies to improve their prey capture, improve hydrodynamic efficiency and avoid collisions. However, the oceanographic drivers, water properties and zooplankton dynamics that lead to such aggregations and behaviours remain a key knowledge gap in understanding the ecology and movement of mantas rays.

Faced with a changing climate that threatens to decrease zooplankton biomass at alarming rates, it is more important than ever to address questions that expand our understanding of sites like Hanifaru Bay to help protect the ecosystems and food sources of significance to manta rays and other planktivores.

This study also aims to explore an undescribed and potentially new manta ray aggregation site on the eastern coast of Australia. K’gari (Fraser Island) is the world’s largest sand island and borders the productive waters of the Great Sandy Marine Park. This site remains mostly open for fishing and is surrounded by an unprotected body of Commonwealth water with high levels of both recreational and commercial fishing activity. While manta rays are protected from targeted fishing in Australia, their interactions with bycatch and fishing gear at this site are unknown and potentially problematic. This study will support the effective management of this site and ensure the safeguarding of the east-coast Australian manta rays.

 FLOSSY BARRAUD

PhD Candidate at the University of Plymouth, UK

Exploring women’s access to the ocean

To sustainably protect the biodiversity that species like mobulids depend upon, coastal communities must act as custodians of their environment. To do this, people may need to (re)connect to the environment. In many ocean-dependent tropical and subtropical nations like the Maldives, Indonesia and Mozambique, women and girls don’t swim, snorkel, or engage with the ocean as men and boys do; 85% of women in low-income countries cannot swim. This exacerbates inequalities and restricts access to conservation decisions and careers, which are often dominated by those from the Global North.

We protect what we love and love what we know. Research shows creating a personal connection to nature improves pro-environmental behaviour, and women are effective changemakers in their families and communities. Ocean-engaged women can become role models and learning to swim, snorkel, surf, or dive can encourage girls to pursue marine conservation careers. For this project, we’ll learn from women in case study communities and our international network, and pilot a locally-led female swim instructor training programme in the Maldives. We’ll use collaborative learnings to create an ‘Ocean Access Strategy’ that outlines tried and tested ways to improve recreational access to the ocean for women in different contexts and cultures, and which can be used by communities and organisations to trial and upscale ocean access programmes worldwide.

 BETTY LAGLBAUER

PhD Candidate at the University of Azores, Portugal

In collaboration with the School of Biomedical Sciences and the Queensland Brain Institute at The University of Queensland, Australia.

Mobulid ray feeding ecology and sensory biology

Manta and devil rays have broad horizontal and vertical movement capabilities spanning coastal, offshore and deep-sea ecosystems. To what extent they use these different habitats for feeding is not well understood, but is important to understand interactions with fisheries, impacts of environmental changes, and to conserve threatened populations. As filter-feeding elasmobranchs, mobulid rays occupy relatively low trophic levels, but some species eat fish or cephalopods in addition to zooplankton. To find food, mates and to avoid predators, manta and devil rays must rely on integrating data from the environment through sensory input. However, nearly nothing is known concerning how they do this. To start answering this question, we are looking into the visual, mechanoreceptive and electroreceptive capabilities of manta and devil rays. Importantly, we hope that the findings of this project will help identify or improve ways to avoid bycatch of mobulid rays in non-selective fishing gear.

 ANA SOBRAL

PhD Candidate at the University of the Azores

In collaboration with Conservation Science Group at the Royal (Dick) School of Veterinary Studies and the Roslin Institute, University of Edinburgh.

Filling the gap: study of the ecology of data-poor pelagic elasmobranchs in oceanic islands in the Atlantic.

Some of the most vulnerable sharks and rays are migratory species that depend on the restricted coastal habitats of oceanic islands. However, the exact role of these habitats for the sustainability of their populations is virtually unknown. This is the case for the Azores, the most isolated archipelago in the North-East Atlantic. To elucidate the role of the Azores, and other coastal habitats in the wider Atlantic, for elasmobranch ecology and conservation, this PhD consists of a population genetic study of three cosmopolitan and threatened species with contrasting life histories: sicklefin devil ray (Mobula tarapacana), tope shark (Galeorhinus galeus) and smooth hammerhead shark (Sphyrna zygaena). A combination of SNPs and mitochondrial DNA will be used to assess population connectivity at multiple geographic scales.

The Azores being one of the few places worldwide where sicklefin devil rays gather in large groups, at predictable aggregation sites, provides a unique opportunity to study them. This species is the only devil ray species to have unique ventral markings, similarly to manta rays, which lead to the establishment of a photo-ID database for this species, as well as the oceanic manta ray (Mobula birostris) through the project Manta Catalog Azores.

Ultimately this results will help support the development of sound management and conservation actions for these species.

 JOANNA HARRIS

PhD candidate at the University of Plymouth

Investigating the movement and foraging ecology of reef manta rays (Mobula alfredi) in the British Indian Ocean Territory (BIOT)

The Chagos Archipelago is relatively untouched by direct human influence. As such, it has one of the world's most pristine marine environments. The subpopulation of reef manta ray (Mobula alfredi) that inhabits this region offers a unique opportunity to study the species in a near-natural environment where the association between environmental variables, distribution and behaviour can be developed to help understand the effects of human pressures and inform conservation management planning for the species throughout their range. To achieve this, my PhD research involves tracking reef manta rays in the Chagos Archipelago using photo-ID techniques and a suite of electronic and acoustic tags which will be integrated with long-term, in situ oceanographic monitoring of manta aggregation sites at Egmont Atoll. This integration of bio-logging data and oceanographic information, as well as stable isotope analysis, will help us learn more about how this species utilises the archipelago's ecosystems, which environmental cues dictate their movements, and what role Chagos Archipelago marine protected area plays as a reef manta ray refuge within the Indian Ocean.

 PAST STUDENTS