Monitoring faunal responses to biodegradable oyster reef restoration materials with camera traps in a subtropical estuary

Oyster reef restoration has become increasingly crucial due to global population declines. Intertidal oyster reefs provide essential foraging and loafing (resting) grounds to estuarine fauna. To reduce plastic pollution from traditional materials, biodegradable restoration materials have been introduced and are shown to support oyster recruitment. However, faunal responses to these materials are unknown. This project evaluated the effects of biodegradable oyster reef restoration materials on vertebrate abundance, diversity, and behavior. Camera traps were deployed on Eastern oyster ( Crassostrea virginica ) reefs in summer 2021, winter 2022, and summer 2022 for a total of 117 days in Mosquito Lagoon, Florida, United States. Treatments included Biodegradable EcoSystem Engineering Elements (BESE) mats with attached recycled oyster shells, cement‐jute tiles, and cement‐jute rings. Unrestored, live oyster reefs were used as positive controls, and unrestored, dead reefs (piles of disarticulated shell) as negative controls, with three replicates of each treatment. A total of 10,872 vertebrates (birds and small mammals) comprising 43 species were observed from 68,890 video clips. Bird diversity, community assemblages, and mammal abundance were similar between treatments. Bird abundance on all restoration treatments was comparable to live reefs, while it was significantly higher on dead reefs (generalized linear mixed model: p < 0.001). Oyster reefs restored with BESE mats and cement‐jute tiles supported the same level of foraging as live reefs, whereas cement‐jute ring reefs and dead reefs exhibited higher loafing activity. These findings highlight the importance of selecting appropriate restoration materials to ensure the success of oyster reef restoration efforts.