WWF-Hong Kong has released a seven-year conservation report calling for stronger protection of Shui Hau sandflat, a vital Hong Kong habitat for the globally Endangered Chinese Horseshoe Crab. The organisation’s research records a 65% fall in overall clam density since 2018, while more than 70% of horseshoe crab sightings were concentrated in only 6% of the sandflat. WWF-Hong Kong has paired the report with a Shui Hau Sandflat Science and Conservation Forum, bringing government, academic and conservation stakeholders together around practical management measures. The findings position Shui Hau as both a biodiversity priority and a test case for balancing public recreation with ecological limits.
Seven Years Of Ecological Evidence
Shui Hau remains a significant nursery area for juvenile horseshoe crabs, particularly the Chinese Horseshoe Crab, Tachypleus tridentatus. Yet the report identifies mounting strain on the wider sandflat ecosystem, linking the sharp decline in clam density to harvesting activity that has exceeded sustainable levels.
The study was developed through WWF-Hong Kong’s community-based conservation project and draws on seven years of monitoring. Such consistent field data offers a valuable picture of changes in an intertidal ecosystem where harvesting, visitor activity and wildlife habitat overlap.
Kelvin So, Oceans Conservation Manager at WWF-Hong Kong, said:
“Grounded in scientific evidence and informed by the expertise of ecologists, academics and conservation groups, this report presents a range of practical recommendations and calls on all sectors to take action for the sustainable future of Shui Hau.”
Kelvin So, Oceans Conservation Manager at WWF-Hong Kong, said:
“The science is clear: the ecological health of Shui Hau is at a tipping point, and we must act now to balance recreational use with the survival of threatened species.”
Concentrated Habitat Risks
The geography of horseshoe crab habitat makes disturbance a particular concern. WWF-Hong Kong found a 16% overlap between juvenile horseshoe crab habitat and recreational activity zones, while the concentration of sightings in a small part of the sandflat means trampling and digging can affect a substantial share of the local population.
The report also points to encouraging evidence from visitor education. Although clam numbers have declined, a greater proportion of visitors were observed avoiding the collection of immature clams. WWF-Hong Kong attributes this behavioural shift to sustained public education, including distribution of clam gauges designed to support more sustainable harvesting decisions.
Professor Hui Tin-yan, Assistant Professor, Division of Science, Lingnan University, and a core member of the expert group, said:
“In Hong Kong, there are few examples of ecologically important coastal sites where systematic monitoring has been conducted consistently across multiple years, generating the datasets needed for meaningful comparisons.”
Professor Hui Tin-yan, Assistant Professor, Division of Science, Lingnan University, and a core member of the expert group, said:
“WWF’s seven years of continuous monitoring at Shui Hau Sandflat have generated a rare dataset that allows us to detect ecological changes, and to understand how human activities are influencing ecological conditions over time. These long-term data not only demonstrate Shui Hau’s significant conservation value, but also provide an important foundation for developing future targeted management measures.”
Technology And Site Management
WWF-Hong Kong’s work at Shui Hau has incorporated AI-assisted clam size monitoring and real-time IoT spatial visitor tracking. The technology is intended to give site managers a more immediate understanding of ecological conditions and visitor patterns, enabling measures to respond to changing activity at the sandflat.
Among the report’s recommendations are a Biodiversity Management Zone for sensitive horseshoe crab and waterbird hotspots, alongside a Wise Use Zone allowing controlled public access. WWF-Hong Kong also proposes a science-based daily visitor capacity, real-time monitoring and alert systems, minimum size restrictions and quotas for clam harvesting, and limits on tools that disturb sediment layers. Small hand rakes would remain permitted under the proposed approach.
The case for structured management has become more pressing as visitor numbers rise during holiday periods, including the Labour Day Golden Week. The organisation argues that action before impacts become irreversible would offer a more constructive route for maintaining both access and the site’s ecological character.
Forum Builds Shared Understanding
WWF-Hong Kong convened its Shui Hau Sandflat Science and Conservation Forum on the day of the report’s release. Participants included representatives from government advisory committees and departments, academia, conservation groups, environmental consultants and other stakeholders, with discussions spanning horseshoe crab conservation, blue carbon ecosystems, visitor management and community engagement.
The forum focused on how science-led cross-sector work could support the sandflat over the long term. Attention was also directed towards the importance of protecting core habitat areas rather than treating the mudflat as ecologically uniform.
Professor Cheung Siu-Gin, Associate Professor, Department of Chemistry, City University of Hong Kong, said:
“One of the most distinctive features of the Shui Hau sandflat is that juvenile Chinese Horseshoe Crabs are not evenly distributed across the sandflat, but are instead highly concentrated in a small area of core habitats. This pattern is relatively rare among Hong Kong’s coastal ecosystems. From a conservation perspective, effectively protecting these key areas brings significant benefits, conversely, even minor disturbance to these core habitats could have a far greater impact than we might expect.”
A Practical Conservation Opportunity
WWF-Hong Kong’s recommendations seek to establish a clearer framework for a site where people, livelihoods and threatened wildlife meet. Its proposed model combines long-term research, public participation and statutory governance, with targeted protection focused on the areas of greatest ecological sensitivity.
The organisation has also linked the report’s recommendations to Hong Kong’s Biodiversity Strategy and Action Plan 2035, identifying area-based conservation as a route to stronger protection for Shui Hau. With detailed monitoring already in place and practical interventions identified, the report offers a credible basis for turning evidence into site-specific action.
Lydia Pang, Head of Oceans Conservation at WWF-Hong Kong, said:
“ Our recommendations allow people to continue enjoy this secluded bay while critical biodiversity areas receive targeted protection they need.”
Lydia Pang, Head of Oceans Conservation at WWF-Hong Kong, said:
“ Our long-term data clearly alerts us the risk of environmental degradation while guiding us to identify the most ecologically sensitive habitats. To ensure its long-term sustainability, we must move beyond voluntary measures. The government’s Hong Kong Biodiversity Strategy and Action Plan (BSAP) 2035 provides a clear vision to enhance conservation of Shui Hau through area-based conservation. We stand ready to work closely with all stakeholders to safeguard this irreplaceable natural asset.”
