Les huîtres, ces architectes essentiels de nos milieux côtiers : Écologie de deux espèces emblématiques, sentinelles du changement global

• Main Author: Pouvreau, Stephane
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: 2023
• Subjects: Cycle de Reproduction; Écologie Larvaire; Déterminisme du Recrutement; Invertébrés benthiques; Ostréidés; Écologie de la Restauration; Conservation; Aquaculture; Conchyliculture; Services écosystémiques; Reproduction Cycle; Larval Ecology; Recruitment; Benthic Invertebrates; Ostreidae; Restoration Ecology; Shellfish Aquaculture; Ecosystem Services; Pacific; Sentinelles; Crassostrea gigas; Pacific oyster
• Online Access: https://archimer.ifremer.fr/doc/00827/93936/100726.pdf; https://archimer.ifremer.fr/doc/00827/93936/

Oysters are essential marine invertebrates in our coastal ecosystems. These architects of the environment provide numerous ecosystem services while supporting a centuries-old economic activity that is flourishing, heritage and structuring in the coastal landscape. Above all, these suspension feeders, capable of reef construction, play a key role in the functioning of many coastal ecosystems by creating remarkable marine biogenic habitats on the foreshore and in the infralittoral domain. There are two species of oysters in France: the flat oyster, Ostrea edulis, native to Europe, and the Pacific oyster, Crassostrea gigas, introduced 50 years ago to save French oyster farming and now naturally established on many European coasts. Even if their origin, history and ecology are different, these two species share a common fate: their essential role in the functioning of ecosystems and the same fragility in front of increasing anthropic pressures. These species are totally dependent on local environmental conditions (temperature, abundance and quality of phytoplankton, salinity, river flow, coastal hydrodynamic circulation, etc.) and more generally on global climate variations. The current climate change, associated with the degradation of their habitats, has direct repercussions on their life cycle, but with major differences depending on the species. By working on these two complementary biological models over the last 20 years, my scientific objective has therefore been to better understand the key processes governing their life cycles in the natural environment. In particular, I have been interested in their ecology, their reproductive cycle, the determinism of their recruitment, the dynamics and maintenance of wild populations, their conservation and then their ecological restoration, all in a coastal environment subject to multiple anthropic pressures. In addition to its primary interest in aquaculture and fisheries issues, my research work has also focused on questions related to the effects of climate change ...