Clara Diaz PhD., MRes.

University of Plymouth


My PhD research focusses on the distribution and diversity of Mesophotic Coral Ecosystems (MCEs) in the Chagos Archipelago. In particular, I am assessing the differences in species composition throughout the depth gradient to determine the role these deeper reefs may play in supporting shallow-water reefs. I am also investigating the environmental drivers of MCE diversity and distribution within the archipelago.

Coral reefs are one of the most iconic and diverse ecosystems in the world. Yet, they are largely threatened by current human activities.
Slightly deeper, reside other incredibly diverse ecosystems, called MCEs (30-150 m). They occupy two thirds of the total depth range of zooxanthellate corals and provide many of the same ecosystem services found in shallow coral reefs.

MCEs study is still at its infancy, which is mostly due to logistical difficulties and safety issues in accessing them. MCEs research has increased exponentially, especially with enhanced technology capacities and after the Deep Reef Refugia Hypothesis formulation by Glynn in 1996. This hypothesis postulates that deeper reefs could provide a spatial refuge and serve as a source of larvae for the recovery of shallow-water coral reefs. On top of that, these ecosystems host an incredible biodiversity, where many of the species inhabiting them are yet undiscovered. However, there is a growing evidence that MCEs are not immune to anthropogenic impacts.

Thus, all these reasons show the importance of studying mesophotic reefs, to better understand them and finally protect them in today’s global context.

Mesophotic coral ecosystems as truly amazing, hosting so much diversity; yet they are already threatened by human activities, revealing the urgent need to study and protect these ecosystems which have still to reveal their secrets.

Clara Diaz


2019 2023
PhD. Candidate, University of Plymouth
2019 2019
Maritime observator, SINAY, Lorient, France
2018 2018
Research project: “Phenotypic plasticity and parental effects: the role of habitat quality in determining larval anemonefish traits” CRIOBE, Moorea
2016 2018
MSc. Oceanography and Marine Environments, Sorbonne Universities (Paris)
2017 2017
Internship “Benthic macrofauna characterisation in Mauritius”, MOI, Mauritius
2015 2016
3rd year BSc. Biological sciences, University of Reading (ERASMUS organisation)
2013 2016
BSc. Biology & Ecology, University Perpignan Via Domitia, France

My Project

  • Island Reef Connections
    Mesophotic Reefs in the Indian Ocean Region

Other interests

I am interested in all tropical benthic species, with a particular interest in the ones populating mesophotic reefs, including scleractinians, soft corals, gorgonians and sponges. I am using a remotely operated vehicle (ROV) and a drop-camera system to undergo my research, collecting both videos and coral samples.

My Publications