Alexia M. A. DIEVART

AlexiaPhD Candidate (Marine Biology)                   

BSc, Université de La Réunion (2016)

MSc, Université de La Réunion (2018)



Project Title 

Photoautotrophic euendoliths and their complex ecological effects on marine mussel beds in South Africa

Mussels are common bioengineers on intertidal rocky shores and support a wide variety of associated species, by buffering thermal and desiccation stresses. Photoautotrophic shell-boring endoliths (cyanobacteria and algae) are common external parasites of mussels and actively bore into the shell, with negative sub-lethal and lethal effects, and surprising beneficial ones. Endolithic infestation reduces the body temperature of sun-exposed mussels through the whitening of the shell during extreme heat events. This beneficial effect can reverberate at the ecosystem level, where infested mussel beds are less hot and more humid than non-infested ones. Alexia investigates the indirect effects of euendolithic infestation of the mussels on their bioengineering qualities and on their associated species, and how these effects may vary spatially and temporally along South African rocky shores.

Supervisor: William Froneman


Originally from France, Alexia completed her BSc and MSc at the University of Reunion Island, in a French overseas territory in the Indian Ocean (La Réunion). During her MSc, she investigated the seasonality of coral spawning with the Marine Reserve in Reunion Island, and came to Rhodes University in 2018 to study the influence of intraspecific divergence in behavior on the quality of habitat offered by marine mussels. In 2017, she funded with her MSc colleagues a non-profit organization, BEST RUN, that aims to study, protect and communicate on the biodiversity of Reunion Island and the Indian Ocean. After working for a year on alien invasive species management in Reunion Island, she returned to Rhodes University to start her phD.


Research Interests:

Ecosystem engineers
Interactions webs
Intertidal communities
Endolithic parasitism




 google scholar link




Recent Publications

  • Nicastro, K.R., McQuaid, C.D., Dievart, A. & Zardi, G.I. (2020). Intraspecific diversity in an ecological engineer functionally trumps interspecific diversity in shaping community structure. Science of The Total Environment 743, 140723. 10.1016/j.scitotenv.2020.140723
  • Dievart, A., Schartz, C., Bracco, I., Amy, E., Ardon, B., Armand, P., Caceres, S., Lavergne, C., Lecouffe, A., Lequette, B., Manikom, R., Payet, N., Rouget, M., Salamolard, M., Strasberg, D., Triolo, J. (2019). Coordinate the fight against invasive alien species: 8 years of operational planning in Reunion Island. Poster. Island Biology 2019 - III International Conference on Island Evolution, Ecology, and Conservation. Saint-Denis, La Réunion. 10.13140/RG.2.2.16952.70402





Last Modified: Fri, 20 May 2022 11:29:57 SAST