Oyster reef restoration in a subtropical bay in China: effects of tidal elevation, reef microhabitats and size on oysters and resident macrofaunal communities
Global oyster‑reef restoration often lacks evaluation outside the USA. In Jiantiao Bay, Zhejiang Province, China, 16 experimental sandstone reef bases were deployed to test how tidal elevation, microhabitat and reef size influence recruitment. Four oyster species—one non‑native and three native—colonized the reefs. Higher intertidal elevation (1.0 m above MLLW) supported greater oyster survival, while reef crests consistently hosted denser oyster and macrofaunal communities than reef bases. Larger reefs (8 m) also outperformed smaller ones (2 m). Oyster densities were positively correlated with resident macrofauna, reinforcing that crest habitats on larger reefs are most effective for establishing diverse communities. These findings align with global patterns and offer guidance for improving reef‑restoration design.
Subject Tags
- Habitat restoration
- Reefs
- Wildlife
Abstract
Efforts to restore natural oyster reefs have grown globally to mitigate losses, but restoration success has not been uniform and is rarely evaluated outside of the USA. During 2019-2020, 16 experimental intertidal reef bases were constructed using natural sandstone in the upstream section of Jiantiao Bay, Zhejiang Province, China. These reefs were designed to simultaneously evaluate the relative importance of tidal elevation, reef microhabitats (base and crest) and reef size on the establishment of oysters and resident macrofaunal communities on the restored reefs 2 yr after deployment. A non-native oyster (Crassostrea hongkongensis) and 3 native oysters (C. ariakensis, C. sikamea and C. angulata) were recruited to the restored reefs. More oysters were recruited and survived on the higher intertidal elevation (1.0 m above mean lower low water [MLLW]) relative to the lower elevation (0.3 m above MLLW), but tidal elevation did not affect the total densities and species compositions of resident macrofaunal communities on the restored reefs. The crest of reefs sustained greater densities of oysters and resident macrofaunal communities than the base of reefs. The 8 m long reefs harbored higher densities of oysters and resident macrofaunal communities than the 2 m long reefs. The oyster densities positively correlated with the resident macrofauna densities on the restored reefs. Our results conformed to the general patterns that crests of larger-sized reefs tend to be more successful in establishing oysters and resident macrofaunal communities.
Citation
Quan, W., Li, N., Liu, Q., Hancock, B., Liu, Q., Zhao, W., ... & Chen, Y. (2025). Oyster reef restoration in a subtropical bay in China: effects of tidal elevation, reef microhabitats and size on oysters and resident macrofaunal communities. Marine Ecology Progress Series, 765, 39-52. https://doi.org/10.3354/meps14892
TNC Authors
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Qing Liu
Climate Resilience Manager, China
The Nature Conservancy
Email: qing.liu@tnc.org -
Boze Hancock
Senior Marine Restoration Scientist, Massachusetts
The Nature Conservancy
Email: bhancock@tnc.org -
Qi Liu
The Nature Conservancy