Public Thesis Defense of Douchan HANUISE - ELI

Informing tropical seagrass recovery in the Great Barrier Reef using a biophysical modelling approach by Douchan HANUISE -

Jeudi 3 septembre 2026 à 12h00 - Auditoire SUD01 - Croix du Sud - 1348 Louvain-la-Neuve -

Seagrasses provide essential services for human well-being, including fisheries habitat, water filtration, coastal protection and carbon sequestration. Globally, these coastal ecosystems have been declining due to the cumulative and interactive effects of coastal development, pollution and climate change. Coastal and catchment management and restoration projects have been implemented to mitigate the impact of these threatening processes. However, the success rate of management interventions is highly variable. A comprehensive understanding of seagrass dynamics, particularly tropical seagrasses, is critical to protect and preserve these ecosystems. For example, dispersal and connectivity of seagrasses supports the replenishment and natural recovery of seagrasses. These processes can be assessed using biophysical models, combining ocean circulation simulations with biological traits. Yet, only few of them account for the interspecific and interannual variability inherent in tropical seagrass ecosystems, suggesting opportunities to improve the predicted dispersal patterns. These dispersal processes have not been assessed comprehensively in one of the world’s largest tropical seagrass ecosystems - the Great Barrier Reef World Heritage Area (GBRWHA) of Queensland, Australia. By using a biophysical modelling approach, this thesis assessed dispersal and connectivity processes of GBRWHA seagrasses to inform their management. Overall, this thesis underscores the importance of modelling parametrization and its impacts on seagrass dispersal predictions. It highlights the value of using robust biophysical models, built on well-considered assumptions including forcing choices, that integrate species-specific traits to accurately capture connectivity. This thesis highlights the drivers of seagrass dispersal in the GBRWHA, that include strong seasonal variations, complex coastal topography influencing wind patterns, and large dispersal variability between species. Broadly, this thesis advances the capacity to model and interpret connectivity in dynamic coastal ecosystems, providing a transferable framework to improve ecological forecasting and guide management strategies.

Jury members :

Prof. Emmanuel Hanert (UCLouvain (Supervisor)
Prof. Alana Grech (James Cook University, Aus.) (Supervisor)
Prof. Marnik Vanclooster (UCLouvain (Chairperson)
Dr. Jonathan Lambrechts (UCLouvain) (Secretary)
Prof. Tom Van der Stocken (VUB)
Dr. Eric Treml (Australian Institute for Marine Sciences)
Prof. Michael Rasheed (James Cook University, Aus.)
Dr. Severine Choukroun (James Cook University, Aus.) 

Pay attention : the public defense of Douchan HANUISE will also take place in the form of a videoconference (Meeting ID: 334 325 588 092 06- Passcode: i7wL6YL7)