Clara Diaz MRes.

University of Plymouth


My PhD research focuses on the distribution and diversity of Mesophotic Coral Ecosystems (MCEs) in the British Indian Ocean Territory (BIOT).

In particular, I will be assessing the overlap of species between the shallow-water reefs and the MCEs to determine the role these deeper reefs may play in supporting shallow-water reefs. I will also be investigating the environmental drivers of MCE diversity and distribution within BIOT and along the depth gradient.

MCEs (30 to 200m depth) are important ecosystems, firstly because of their surface area: they occupy two-thirds of the total depth range of zooxanthellate corals and secondly because they support economically- and ecologically- important endemic species. However, research on these ecosystems is still at its infancy, as access to MCEs is difficult due to the depth they are found.

Coral reefs are in crisis from a combination of direct human impacts and pervasive effects of climate change. A possible refuge for reef species occurs in deeper waters, with MCEs. The potential importance of these mesophotic reefs as refuges from the effects of climate change has only recently emerged. This is known as the Deep Reef Refugia Hypothesis (DRRH) and the ‘refuge’ sites may play an important role in the recovery of degraded shallow reefs by providing sources of larvae. On top of that, these ecosystems host an incredible biodiversity, where many of the species inhabiting them are yet undiscovered.

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

There is a high imperative need to study and manage these precious ecosystems, as they occur in areas which face increasing environmental change and human impacts

Clara Diaz


2019 Present
PhD. Candidate, University of Plymouth
2019 2019
Maritime observatory, 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

  • Coral Reef Resilience
    Mesophotic Reefs in the British Indian Ocean Territory

Other interests

I am interested in all invertebrate and slow moving species of mesophotic reefs, including scleractinians, soft corals, gorgonians and sponges. I am interested in the non-destructive methods to study coral reefs, that is why I am using a ROV to undergo my research, for both video transects and coral sampling.