Jonathan Monsinjon1, Gerardo Zardi1,2, Katy Nicastro1,2
1UMR 8187 – LOG – Laboratoire d’Océanologie et de Géosciences (Univ. Lille, CNRS, Univ. Littoral Côte d’Opale, IRD), France - 2Rhodes University, South Africa
Ecological interactions are crucial to ecosystem health, influencing species diversity and resilience. In intertidal habitats, mussels are key bioengineers, supporting diverse communities. However, they face significant biotic pressures from microbial endolithic symbionts, which can degrade their shells and impact their overall fitness. This complex relationship is dualistic; while these symbionts weaken mussel shells, they may also confer benefits under certain conditions. Despite research on endolithic infestation impacts, the environmental drivers and their spatial and temporal patterns remain unclear. This study aims to develop a predictive model for infestation probability based on various environmental variables. Mussels (Mytilus galloprovincialis and M. edulis) were collected from 14 sites across 27° of latitude in the northeastern Atlantic between 2011 and 2024, where infestation levels and size classes were assessed. Eight dynamic variables (air temperature, solar radiation, significant wave height, chlorophyll-a concentration, net primary production, sea water temperature, salinity, and pH) and two static variables (distance to the nearest sandy beach and tidal range) were sourced from online databases. Mussel size class was included as a predictor. A machine learning algorithm (Random Forests) was trained using 2 to N predictors, retaining the combination that showed optimal performance. Infestation probability was predicted in 25-km hexagonal grid cells along the coastline at monthly intervals. Size-specific spatiotemporal trends are presented, providing insights into endolithic infestation dynamics over nearly 14 years along the coastlines of Western Europe and North Africa. The findings will prove useful for predicting the impacts of climate change on intertidal ecosystems and for informing conservation strategies aimed at preserving the ecological functions provided by mussel beds.
Biography
Jonathan Monsinjon is a postdoctoral researcher specializing in ecological modeling. He earned his PhD in 2017, focusing on sea turtle embryo development under climate change. He conducted fieldwork on sea turtle nesting in French Polynesia, Costa Rica, and Brazil. His postdoctoral research spans thermal ecology of intertidal mussels, sea turtle movements in the Indian Ocean, and distribution modeling of marine species, informing policies like the Marine Strategy Framework Directive.