MEPS - Vol. 582 - FEATURE ARTICLE

Feedback mechanisms driven by reef height result in threshold responses of oyster populations leading to diverging reef trajectories toward degradation or persistence. Photos: Allison M. Colden

Colden AM, Latour RJ, Lipcius RN

 

Reef height drives threshold dynamics of restored oyster reefs


Oyster reefs worldwide have been devastated by overharvesting, disease, and habitat loss. Previous restoration efforts have identified a dichotomy of restoration outcomes characterized by persistent reefs with high oyster density or degraded reefs with low oyster density and habitat loss. Colden and colleagues demonstrate that this dichotomy is driven by nonlinear threshold responses in oyster demographics dependent upon initial reef height, with a threshold at approximately 0.3 m. After 2 yr, reefs >0.3 m support large oyster populations and experience little sedimentation; at ≤0.3 m, reefs support few oysters and experience heavy sedimentation and burial. This study provides strong support for alternative states in oyster reef ecosystems and demonstrates an avenue by which restoration is achievable.

 

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