WWF launched Hong Kong’s First Code of Conduct and Clam Gauge for clam digging activities | WWF Hong Kong

WWF launched Hong Kong’s First Code of Conduct and Clam Gauge for clam digging activities

22 August 2019

Unregulated Clam Digging threatens Hong Kong’s Ecosystem

In recent years, a number of coastal areas in Hong Kong have become ‘clam digging hotspot’ for tourists. Clam serves an essential role in cleaning up waterways and supporting the food chain in intertidal mudflat. However, under the existing legislations in Hong Kong, recreational clam digging activities are not regulated unless the activities are taken place within the marine park or marine protected area. Insufficient regulation on clam-digging activities will lead to overharvesting which may result in declining number of clam species and reproduction opportunities, as well as changes in community structure and a clash in clam diversity, causing serious disturbance to the ecology. Moreover, excessive recreational activities will also disturb important marine living creatures or habitats, such as horseshoes crab and seagrass bed.

Collaboration to formulate conservation tools with Pilot Project in Shui Hau

Located on the Southern part of Lantau, Shui Hau has a rich variety of coastal habitats with a relatively high biodiversity, including mangrove, intertidal sand and mud flat, boulder shores and rocky shores, as well as “Living Fossils” horseshoe crab. As a ‘clam digging hotspot’, considerable concerns, yet, are aroused due to unregulated clam digging activities.

With the support from the Government’s Environment and Conservation Fund and the Environmental Campaign Committee, WWF-Hong Kong (WWF) initiated the ‘ECF Sustainable Shui Hau Project’ in 2018. Collaborating with academics and local residents in Shui Hau, WWF launched a set of Code of Conduct as a guideline for responsible clam-digging activities and formulated clam gauges for common clam species in June 2019. It aims at reducing the negative impacts of recreational activities to ecology and encouraging sustainable use of marine resource and ecotourism.

The Code of Conduct is the first of its kind in Hong Kong. It is developed for clam-digging activities and serves as a guideline to encourage public to follow. It suggests 8 rules for clam diggers, e.g. releasing small clams to allow them to grow and reproduce, using less destructive equipment and backfilling clam holes etc. Combining the result of literature review and ecological survey, WWF has designed a set of ‘clam gauge’ for the 5 frequently collected clam species in Hong Kong, with suggestions on the minimum size for capture in Hong Kong after taking reference from statutory requirements in other countries. WWF has designated the minimum size of catches for the Asiatic hard clam (Meretrix spp.) to be 40mm (or 4cm). For the 4 other clam species (False Cockle, Comb Venus, Chinese Venus, Manila Clam), the recommended minimum size for capture is 30mm (or 3cm). To manage clam resources, clam diggers are strongly encouraged to do measurements and follow the suggestions laid down in the Code of Conduct to avoid taking away small clams that are not matured to allow their growth and reproduction, which will help the supply for new clams in future.

To build awareness in the community, WWF has engaged 4 local stalls in the nearby area to educate public to follow the Code of Conduct and explain the usage of clam gauges. The conservation tool set designed by WWF will be made available to visitors when they hire clam digging tools. In using the conservation tool set, negative impacts from clam digging will be reduced through promoting and education on sustainable use of marine resource in our community.

Long terms conservation measures
There are regulatory practices in other countries on managing fishery resources, e.g. fishery plans to control clamming activity including annual population surveys, exploitation plan, monitoring and control; exploitation plans including a permit system limiting the harvest season, zoning, number of people, gear and catch, such as the clam quota and size. For proper management of marine resources, WWF suggests the Government to strengthen the management on human activities in ecological sensitive shore areas. 

Any opinions, findings, conclusions or recommendations expressed in this material/ event do not necessarily reflect the views of the Government of the Hong Kong Special Administrative Region and the Environment and Conservation Fund.