Guy Stevens PhD.

The Manta Trust


Although manta rays are among the ocean's largest and most charismatic species, a conservative life history, coupled with targeted and bycatch fisheries throughout their range, marks these zooplanktivorous elasmobranchs extremely vulnerable to exploitation.

Reef manta rays occur in dispersed, generally small, subpopulations, although at certain important ‘hot-spot’ locations, large aggregations periodically occur. However, the biological and oceanographic processes which drive these aggregations, the degree of connectivity between sub-populations, and the overall large-scale movement patterns of this species, are all poorly understood. Without a detailed understanding reef manta ray ecology, spatial and temporal patterns of distribution, and the environmental drivers of these, it is difficult to quantify and mitigate the effects of different anthropogenic pressures upon this species.

The remote areas of the Indian Ocean Region consists of the near-pristine Chagos Archipelago. The location supports an un-fished population of reef manta rays, with several hot-spot aggregation sites for this species within the archipelago, making it an excellent study location.

The Chagos Manta Project is tracking reef manta rays in the Chagos Archipelago using photo-ID techniques and a suite of electronic and acoustic tags; later integrating this data with ecological and oceanographic datasets. This integration of bio-logging data, stable isotope analysis and oceanographic information, with a focus on the manta aggregation site at Egmont Atoll, is helping us learn more about how this species utilises the archipelago’s ecosystems, which environmental cues dictate their movements, and what role the Chagos Archipelago plays as a reef manta ray refuge within the Indian Ocean.

For me, the connection you feel on a personal level to the individuals is key. After 15 years of research and thousands of hours spent in the water with these animals, you get to know their personalities and lives, and appreciate the impacts we as humans are increasingly having upon them. I think as humans we are increasingly losing our empathy towards the natural world because we have lost that connection. Put simply, we no longer care. I hope that through my work manta rays can act as vehicles to draw people through the looking glass so they can connect with our oceans and their inhabitants, and care enough to make a difference.

Guy Stevens


2011 Present
Chief Executive and Founder of the Manta Trust
2005 Present
Founder of the Maldivian Manta Ray Project
2017 2017
Awarded the UK Prime Minister's Points of Light Award
2005 2016
Ph.D. on the world's largest population of reef manta rays
2015 2015
Awarded the Ocean Award for my work on manta rays
2002 2002
Degree in Marine Biology and Coastal Ecology at University of Plymouth

My Projects

  • 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

I have spent the last 15 years studying mobulids (manta and devil rays) all over the world and am one of the foremost experts on these species. Manta rays are beautiful creatures, their grace and inquisitive nature captivating. They engage and stir my natural curiosity like no other marine creature, driving my desire to protect and learn as much about them as possible.

Internationally, I am part of a team which has driven the conservation of mobulids forward, resulting in the listing of all manta and devil rays in the Appendices of the Convention on the Conservation of Migratory Species of Wild Animals (the Bonn Convention) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Additionally, my conservation efforts in the Maldives have led to the creation of several marine protected areas at key manta aggregations sites, most notably in Hanifaru Bay.

Author of the award-winning: MANTA: The Secret Life of Devil Rays (2017) and A Guide to Manta and Devil Rays of the World (2018).