link to open access paper https://onlinelibrary.wiley.com/doi/10.1111/rec.14169

This is a restoration success story. Despite being eradicated from the mainland, this restoration has shown that this functionally extinct ecosystem still has a heartbeat. Seeded by larvae supplied by the few remaining individual oysters, hectare-scale recovery is demonstrably possible when appropriate substrate is deployed in alignment with recruitment events (McAfee & Connell 2020). Many marine organisms possess traits that can enable rapid ecological change; e.g. short life histories and larval stages characterized by broad dispersal and high propagule supply (Carr et al. 2003). This means that coastal seas can be a soup of larvae dispersing without the physical barriers that restrict movement on land (e.g. roads and fences), so even degraded sites may still receive a high propagule supply from neighboring areas. These traits suggest that marine restorations are well placed to deliver rapid successes that provide optimism for repairing the sea (Duarte et al. 2020). Importantly, the success of this restoration rests with the main non-human collaborators, the oysters themselves. Indeed, it is the surprising resilience of these oysters, their capacity to endure centuries of exploitation and mismanagement, that provides inspiration and hope for restoration programs that can support a more sustainable future.

Such optimism for marine restoration must also be grounded in reality; marine systems are highly complex and ever-changing. Not all restorations will succeed, and many may require lengthy periods to achieve their goals. For example, a similar oyster reef restoration within the same gulf has developed comparatively slowly, possibly due to spatial competition from other rapidly colonizing organisms (i.e. McAfee et al. 2021b) or spatial variability in environmental conditions (e.g. food availability and water quality) that influence oyster performance (Leong et al. 2022). Additionally, it remains uncertain what impact the high density of these restored oysters may have on pathogen prevalence (Buss et al. 2019), and whether limited parent stock seeding of these reefs may create a genetic bottleneck among the restored population (Reynolds et al. 2012). And for restorations of ecosystems that were degraded before extensive study or recent social memory, limited knowledge on the historical community structure and function challenges decision-making, such as which species combinations and ecological services to prioritize.