Joanna Harris BSc (Hon), MRes

University of Plymouth & the Manta Trust


My research involves studying the dynamic relationship between reef manta rays (Mobula alfredi), zooplankton and physical oceanography.

This is research is key in allowing us to gain a better understanding of how reef manta rays uses the archipelago ‘s ecosystems and which environmental cues dictates their movements. Additionally, it will also give us a precious insight into the role of the Marine Protected Area (MPA) surrounding the Chagos Archipelago as a refuge for this species within the Indian Ocean. In order to gather such information, I will be using satellite and acoustic telemetry, in-situ plankton sampling coupled with oceanographic monitoring.

I believe this study will also highlight the impact human activities and climate change have on reef manta rays. Thus enabling a more accurate identification of the threats to the conservation of reef manta ray populations worldwide.



The Chagos Archipelago population of manta rays inhabit an almost pristine marine environment and as such, can help us to understand natural processes that influence their survivorship, which will inform conservation management throughout their range.

Joanna Harris


2019 Present
Ph.D. Student, University of Plymouth
2019 Present
Chagos Manta Ray Project Leader, Manta Trust
2018 2019
MRes in Applied Marine Science, University of Plymouth
2018 2019
Research project, Habitat use of reef manta rays, in the Chagos Archipelago, Manta Trust
2017 2018
Research project, Spatial Ecology of the Reef Manta Ray in the Maldives, Manta Trust
2015 2018
BSc (Hon) Applied Marine Zoology, Cornwall College Newquay
2014 2015
Scuba Teaching Assistant, Atlantic Scuba
2013 2014
Dive Centre Internship (SDI/PADI), Atlantic Scuba

My Projects

  • Species Distribution and Ecology
    Multi-Scale Oceanographic Numerical Modelling in Support of Regional Marine Science
  • Species Distribution and Ecology
    Reef Manta Rays in the Indian Ocean Region
  • Island Reef Connections
    Mesophotic Reefs in the Indian Ocean Region
  • Species Distribution and Ecology
    Internal Waves as an Oceanographic Driver of Ecosystem Variability

Other interests

The reef manta ray (Mobula alfredi) are precious creatures subject to increasing pressure both from human activities and climate change. Direct exploitation for their gills has recently increased following a rise in demand from traditional Chinese medicine caused an added pressure on manta ray populations. Nonetheless, the often overlooked touristic pressure on these animals is increasingly threatening this species and its habitat. While working in the Maldives my research focused on identifying key areas of habitat use where such pressure is increasing. I was able to identify drastic habitat and temporal changes in the way reef mantas use these areas and, thus, enabled more effective conservation management practices.

My Publications