City of Shells: Our Forgotten Oyster Reefs (香江遺礁) is a new documentary uncovering the story of Hong Kong’s lost oyster reef ecosystems and the efforts now underway to bring them back. Directed by Mike Sakas, the film follows scientists, restoration experts, and citizen explorers as they reveal the ecological and cultural importance of oyster reefs — and why their recovery is essential to the city’s environmental future.
Oyster reefs are one of the most endangered marine habitats globally, with over 85% lost due to pollution, overharvesting, and urban development. Hong Kong, once home to rich shellfish ecosystems, has seen its reefs dredged, mined, and buried under reclamation. Despite their ability to filter water, support biodiversity, and protect coastlines from erosion, oyster reefs remain largely unrecognized in local conservation policy.
Through historical research, underwater expeditions, and ecological surveys, the film retraces how oyster reefs once supported livelihoods and marine health across the Pearl River Delta — and how they can again. Restoration at scale could transform degraded waters and strengthen climate resilience.
The Nature Conservancy (TNC), alongside partners including The University of Hong Kong’s Swire Institute of Marine Science and The Explorers Club Hong Kong, is proud to support the film and advance oyster reef restoration in the region.
The documentary is available to watch and download at www.cityofshells.com, and will also be featured at ReThink HK 2025, inviting audiences to rediscover a vital chapter of Hong Kong’s ocean heritage.