Bouncing back from macroalgal-dominated reefs: microbial and chemical effects of algal removal and coral transplanting

Scientific background: Climate change is causing major ecological shifts, with important consequences for ecosystem functioning. In coral reefs, coral-algal transitions are the most well-known shift. Following algal increases, an array of mechanisms that reinforce algal dominance and prevent coral recovery are established.

For example, algal chemicals can promote changes in microbial communities, negatively affecting corals. Algae can damage corals upon contact through the presence of chemical defences or by transferring opportunistic bacterial pathogens. To date, understanding of these mechanisms, their reversibility, and their effects on key reef functions remains limited.

The objective of this project is to investigate the microbial and chemical mechanisms that reinforce algal-dominated reefs and to evaluate if algal removal and coral transplantation can reverse these mechanisms to help recover coral-dominated reefs.

Methodology: The student will study macroalgal-dominated coral reefs undergoing different interventions near the island of Moorea (French Polynesia). The microbial and chemical landscapes of these ecosystems will be studied using metabarcoding and metabolomics. Different experiments (coral settlement and herbivore deterrence) will be carried out at the University of Plymouth and the University of Derby to investigate the effects of macroalgae on key reef functions.

Training: The student will receive exceptional training in metabolomics, microbiology, bioinformatics, marine fieldwork and in writing scientific publications. The student will learn good laboratory practice and quality assurance, and will present their findings at team meetings, international scientific conferences, and in peer-reviewed scientific publications. The skillset acquired will be relevant to careers in academia, biotechnology, and ngo/governmental conservation roles.

This project links to a wider international project that explores the effectiveness of coral restoration interventions, allowing the student to become part of a vibrant international team. The student will participate in at least one field season at CRIOBE (Moorea). The student will be allowed freedom to modify the project design, depending on own interests and skills, within the broad scope of the project's aims.