A small boat sits in mud near the shore that is lined with discarded oyster shells.
Discarded shells Oyster shells are discarded on the shore in Deep Bay. © Anniqa Law/TNC

Hong Kong Projects

Less Trash and More Reefs

Turning Waste Into Value For Hong Kong’s Oyster Shells

The Nature Conservancy (TNC) in Hong Kong is embarking on a new initiative called “Save Our Shells” that will recycle and reuse discarded shellfish shells, like oysters and mussels, from the aquaculture and restaurant industry. These shells would normally go into landfills or discarded as trash on the shoreline but we repurpose them into substrate for new, living reefs. These reefs in turn will provide a range of benefits, serving as habitats for juvenile fishes and other marine life, as natural filter feeders that improve local water quality and as shoreline stabilizers.

Oysters aren’t just good for eating—their shells are made of natural materials that are the perfect substrate for new reefs to grow on.

TNC is recycling oyster shells. The shells are used to rebuild new reefs that can improve water quality and the environment.

Leaning on expertise gained from TNC’s successful oyster shell recycling and reef restoration projects around the world, we will provide a solution for the food and beverage industry as well as aquaculture farmers to recycle discarded shells, thereby lowering the negative impact on the environment and diverting food waste from the landfill. And because there will be a way to properly store and sort oyster shells that are usually mixed with non-natural debris, we will be reducing the negative impact discarded shells have on Hong Kong’s natural coastlines, creating a cleaner environment for native species such as seagrasses, horseshoe crabs and shorebirds.

In addition, oyster shells are high in calcium carbonate and can be used as a high-quality soil additive or as a fertilizer supplement for local farmers. We aim to mill oyster shells for this purpose.

This technique has been used successfully by TNC in the United States and around the world for more than 15 years.

Restoring Hong Kong’s Lost Shellfish Reefs

Shellfish reefs are the most endangered marine habitat on the planet with an estimated 85 percent global loss. In Hong Kong, overharvesting and coastal development have destroyed much of the city’s shellfish reefs, degrading local marine environments and jeopardizing livelihoods. With the support of our partners, TNC has established two pilot reefs to monitor their impact on biodiversity, establish a baseline of local oyster habitats and biodiversity and study the feasibility for new growth to bring back Hong Kong’s shellfish reefs at scale.

Recycled oyster shells and mussel shells are in different bags.
Recycled shells Different types of shells are sorted and bagged to create new shellfish reefs. © Anniqa Law/TNC

Our Partners

Recycling oyster shells into thriving reefs will only succeed with community partners. Currently, TNC is supported by donors JP Morgan and SUEZ. 

Participating restaurants are the Royal Hong Kong Yacht Club, Cordis, Hong Kong, The Verandah at The Repulse Bay and the Oyster Station.

TNC also appreciates the support from oyster farming communities, Ha Pak Nai communities, Hong Kong Design Institute and Food For Good. 

If you’d like to help Save Our Shells and repurpose these shells to reduce waste and bring benefits to our local marine environment and communities, contact us at natureworkshk@tnc.org

“SUEZ strives to protect the oceans worldwide and we spare no effort to facilitate the collection and recycling of waste in Hong Kong. As a proud supporter of TNC’s ‘Save Our Shells’ initiative, the success of which has led to the conservation of coastal biodiversity for our partnership in Australia, we believe it can help divert waste from Hong Kong’s landfills and help preserve the ecosystem in Ha Pak Nai. We hope the program will also raise public awareness on the importance of waste recycling at source in the long run,” said Joey Choi, Chief Sustainability and Communications Officer, SUEZ Asia.

Recycle the Reefs Factsheet

  • Turning Waste Into Value for Hong Kong's Oyster Shells

    Less Trash and More Reefs

    Turning Waste Into Value for Hong Kong's Oyster Shells

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