Alexis Pey - Research Assistant
Marine Biology and Ecology

Master degree in Marine Biological and Ecology at the Mediterranean Institute of Oceanology (Marseille, France), I obtained in 2012 my Phd Degree in “Fundamental and Applied Sciences” at the University of Nice-Sophia Antipolis (France), with a thesis entitled « Biochemical and physiological responses of temperate marine symbioses to climate warming » (advisors: Pr. Paola Furla and Dr. Pierre-Laurent Merle, UMR 7138, Marine Symbiosis team). Thanks to multidisciplinary approach (Ecology, Biochemistry, Molecular biology, Physiology and Population Genetics), these doctoral studies aimed to better define the answers induced by thermal stress of two Mediterranean symbiotic Cindarians: the white gorgonian Eunicella singularis and the sea anemone Anemonia viridis. These researches allowed me to specialize in these environmental issues concerning conservation and protection of these fundamental species.

In 2010, I obtained my professional diving certification (CAH1B), training organized by the CNRS to the biological station of Roscoff (France), which allowed me to be skilled for various technical diving qualifications. Then, I participated and organized various field missions, that allowed me to establish several collaborations with organizations working on marine conservation and other environmental issues (ECOMERS laboratory, Nice; DIMAR Laboratory, Mediterranean Institute of Oceanology, Marseille; Arago laboratory, Biological Oceanography Laboratory of Banyuls-sur-Mer; The Blue Coast Marine Park, Carry-le-Rouet; National Park of Port-Cros; Mediterranean station of the coastal environment, Sète).

In May 2016, I have been contracted as Research Assistant by Sylvaine Giakoumi on the PAVIS Project. During the 2 next years, my main role is is to help to the organisation of field missions and carry out the experimentation in 9 marine protected areas (MPAs) in 6 Mediterranean countries (Spain, France, Italy, Croatia, Greece and Turkey). PAVIS will investigate the following hypotheses:

1) whether MPAs influence the expansion of invasive species and mitigate their effects on native assemblages,
2) whether the ecological effects of such species could alter, reduce, or nullify ecosystem responses to protection in MPAs, and
3) whether local economic activities, such as artisanal fisheries and recreational diving, performed in MPAs and adjacent areas, have been impacted by the presence of invasives.

Previously, I joined the ECOMERS lab as a postdoctoral fellow in 2014. First, I joinedthe « Macrophytes Team » for 7 months to work mainly on the conservation and the ecological restoration of the large brown seaweeds forests, especially Cystoseira spp. in Mediterranean Sea (in France, Monaco and Montenegro). I worked on the study of heat pump discharges effects on shallow benthic littoral communities in Monaco, and on the study of the ecology of the benthic toxic dinoflagellate Ostreopsis cf. ovata. I was involved in 4 national and european projects: Optima PAC, MMPA, Coconet Project and M3HABs. Then, I joined the « Fish Team » at the beginning of 2015 for 6 months to work on the marine cave ecology (marine cave project) in the French Mediterranean Sea by assessing the fish assemblages in selected marine caves and the potential of the cardinalfish Apogon imberbis as a vector of trophic resources in the inner portions of caves.


Année 2017

Gianni F., Bartolini F., Pey A., Laurent M., Martins G., Airoldi L., and  Mangialajo L. (2017). Threats to large brown algal forests in temperate seas: the overlooked role of native herbivorous fish. Scientific Reports.


Giakoumi S. and Pey A. (2017). Assessing the effects of marine protected areas on biological invasions: a global review. Frontiers in Marine Science4, 49.


Bussotti S., Di Franco A., Pey A., Vieux-Ingrassia J.V., Planes S. and Guidetti P. (2017). Distribution patterns of marine cave fishes and the potential role of the cardinal fish Apogon imberbis (Linnaeus, 1758) for cave ecosystem functioning in the western Mediterranean. Aquatic Living Resources


Pey A., Zamoum T., Christen R., Merle P. L. and Furla P. (2017). Characterization of glutathione peroxidase diversity in the symbiotic sea anemone Anemonia viridis. Biochimie, 132, 94-101.

Link Researchgate: Pey et al., 2017


Année 2013

Pey A., Catanéo J., Forcioli D., Merle P.L. and Furla P. (2013). Morphometric and genotypic analysis of the Mediterranean symbiotic gorgonian Eunicella singularis exposed to thermal stress: Assessment of the maximum thermal threshold and first evidence of a genetic basis for thermotolerance. Comptes Rendus Biologies, 336 : 331-341.

 Link Researchgate: Pey et al., 2013


Année 2011

Pey A., Zamoum T., Allemand D., Furla P. and Merle P.L. (2011). Cellular physiology of depth-dependent thermotolerance of the symbiotic Mediterranean gorgonian Eunicella singularis. Journal of Experimental Marine Biology and Ecology, 404 : 73-78.

 Link Researchgate: Pey et al., 2011


PhD thesis abstract:




       Global climate change leads significant reactions on marine ecosystems which, when dealing with sessile species, can drive to episodes of mass mortalities. In the north-western Mediterranean Sea, recent events of mortalities severely impacted gorgonian communities, threatening their survival, but also all the associated biodiversity. The implementation of strategies of preservations requires preliminary acquisitions of the knowledge at ecological, evolutionary, physiological, biochemical, genomic and genetics levels. In this ambitious framework, these doctoral studies aimed to better define the answers induced by thermal stress of two Mediterranean symbiotic Cnidarians: the white gorgonian Eunicella singularis and the sea anemone Anemonia viridis.

         A first part of the works was carried out on two populations of the white gorgonian, associated with their photosynthetic symbionts (zooxanthelles), collected at two geographical zones with contrasted thermal profiles. This study allowed us to identify the superior limits of thermal resistance of the populations and to estimate the possible links between the genetic varieties of the hosts and the symbionts, and their thermal resistance.

          Complementary studies then allowed identifying, on this symbiotic gorgonian, early molecular indicators induced by a hyperthermia, implying the global antioxidant defenses capacities and the degree of protein ubiquitination.

         Finally, our studies led on the sea anemone allowed to deepen our knowledge developed on this model concerning the antioxidant enzymes and in particular the glutathione peroxidases (GPx). The measures of the GPx activities in the different holobiont compartments did not reveal major modifications during the stress, but the appearance of one activity band induced by the hyperthermia could represent a new potential marker of stress.


Key-words: Global warming; Symbiotic Cnidarians; Mediterranean gorgonians; Thermotolerance; Biomarkers; Oxidative stress.