Research Profile | Jule Buschmann | MSc Marine Science & Climate Change

How Reef Manta Rays (Mobula alfredi) use cleaning stations and interact with cleaner fish in southern Mozambique
28th February 2024

Describe your MSc project?

My research project aimed to strengthen the understanding of how reef manta rays (Mobula alfredi) use cleaning stations and interact with cleaner fish in southern Mozambique. Reef manta rays are classified as vulnerable to extinction on the IUCN Red List of Threatened Species. Major threats to the species include targeted fishing and incidental capture as bycatch, entanglement in fishing and mooring lines, vessel strikes, unregulated tourism, pollution and habitat loss. Increased marine management and conservation measures are required to protect the reef manta ray population in southern Mozambique and understanding their habitat use is an important piece of the puzzle. For my research project, I used remote underwater video (RUV) to assess visitation patterns to cleaning stations, the impact of environmental factors and the presence of other elasmobranch species on cleaning station visits, behaviours displayed by reef manta rays at cleaning stations, which cleaner fish species have mutualistic relationships with reef manta rays and whether different cleaner fish species specialise in cleaning different parts of a reef manta ray’s body.

What type of research has it involved and what skills have you learned?

During the preliminary phase of my project, I carried out a systematic literature review in line with the PRISMA framework to obtain a comprehensive overview of existing research on reef manta rays, methods used to study the species and to identify gaps in knowledge. Following the literature review, I collected remote underwater video data, which involved SCUBA diving for camera deployments and retrievals. AOA staff, trained volunteers and I jointly watched and analysed 263 hours of video footage, recording any sightings of reef manta rays and other marine megafauna species. For each reef manta ray sighting, I assessed the behaviour displayed by the manta and identified any cleaner fish interacting with the reef manta ray to species level. During this project, I also learned to perform statistical analyses in RStudio, working with different regression models (GLM, GLMM, zero-inflated GLM, hurdle model) and selecting the model that best fit my data. Graphic design skills acquired throughout the academic year were put to use in creating an infographic to communicate the findings of my research to local stakeholders.
In addition to conducting my own research, working with All Out Africa allowed me to present my work to volunteers and dive centre staff on several occasions, conduct humpback whale surveys and microplastic surveys with the volunteers and to identify whale sharks based on their unique spot pattern.

Were there any partners/stakeholders on your project?

Field work for this research was carried out in cooperation with the Marine Research Centre of All Out Africa (AOA) in Praia do Tofo, Mozambique. AOA kindly allowed me access to their facilities, research equipment and, most importantly, video data collected prior to my arrival in Mozambique. Their invaluable support and extensive knowledge of marine life in southern Mozambique played a key role in this project’s success.

Why should the public know about this topic?

Charismatic species like reef manta rays attract tourists from all over the world. In recent years, manta ray tourism has emerged as a more sustainable and economically viable alternative to fishing and while this is a positive development in terms of protection of the species, irresponsible behaviour by tourists can disturb animals’ natural behaviours, interrupting vital cleaning and feeding activities. My research highlights the importance of cleaning stations to the health of reef manta rays, especially for parasite removal and wound healing. By raising awareness of the importance of such cleaning sites to the local reef manta ray population, my research can be used to inform future conservation measures, which, in the long-run will provide economic benefits to the local community and businesses.

What is the wider impact of your research?

My research contributes to the understanding of habitat use by reef manta rays in southern Mozambique, highlighting the importance of cleaning stations as key areas for conservation. This study has provided baseline data on interactions between reef manta rays and different cleaner fish species at one reef in southern Mozambique, which could in the future be expanded to nearby reefs, allowing for an assessment of differences between cleaning stations in terms of cleaner fish composition and abundance but also functionality for client species. An improved understanding of cleaning stations can inform future conservation measures and open up new areas of research into these important aggregation sites. In addition, my dissertation provides recommendations for the conservation of reef manta rays in southern Mozambique. Given the substantial declines in reef manta ray sightings over the last two decades and continued pressures from fishing and tourism, I recommend the creation of a Marine Protected Area (MPA) in Tofo Bay and the surrounding reefs. Reef manta ray tourism has substantial economic value and future conservation efforts will not only benefit the local reef manta ray population but local businesses and the community alike.
As one of the first studies worldwide using long-life remote underwater video cameras for marine research, this study greatly improved upon the current methodology of using action cameras, which are limited by their battery life. Long-life remote underwater video provides many opportunities for monitoring the marine environment, studying elusive and rare species and documenting the behaviour and habitat use of marine species while minimising disturbance. Rapid developments in artificial intelligence and machine learning have the potential to substantially reduce the time and effort required for data processing and analysis, thereby enabling comprehensive, long-term monitoring of marine environments. As such, the use of RUV has the potential to open up new avenues of marine research, allowing for more effective conservation strategies and protection of marine ecosystems.

Comments from Head of School

Jule’s research has huge implications for conservation of charismatic megafauna such as reef mantas. By outlining the importance of ecologically important areas such as cleaning stations, we can better understand how to sustainably manage areas for the benefit of these vulnerable organisms. The present research is a great example of how to scale up from ecology to policy. We thank Jennifer Keeping (Marine Research Director) and All out Africa for supporting Jule’s research project.
Jule came through the programme from a non-traditional route, i.e. from a background in finance. Through determination and hard work, Jule graduated from the programme and was awarded Class Valedictorian 2023. Jule is now Marine Research Coordinator at All out Africa, Tofo Mozambique. For more information on All out Africa and volunteering opportunities, search: aoa_marine_projects on Instagram.
Dr Awantha Dissanayake, Head of School (Marine & Environmental Sciences)
  • MSc

    Master in Marine Science & Climate Change

    Designed and delivered by expert academics and scientists, this full or part-time interdisciplinary programme blends theoretical study with practical, field-based work. You will cover specialist subject areas and gain the skills required to tackle the complex issues associated with the sustainable development of marine ecosystems.[...]

    1 Year

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