Each spring, as Shenzhen’s mangroves burst into life, the region becomes a prime spot for birdwatchers observing the endangered, black-faced spoonbill. Known as the giant panda of birds, this species winters in Shenzhen Bay from October to April, in preparation for its northbound migration. Shenzhen Bay, located in southern China and part of the Pearl River Delta expanding into Hong Kong, is a crucial stop-off point for migratory birds using the East Asian-Australasian flyway. The mangroves support over 200 species of birds and host 100,000 migratory birds each winter, drawing enthusiasts and scientists alike to witness these natural spectacles against the backdrop of one of China’s most bustling urban settings.

Shenzhen Bay is a crucial stop-off point for migratory birds using the East Asian-Australasian flyway. Graphic by Harry Zhang / Dialogue Earth

Amid the rapid urbanization that defines modern China, Shenzhen stands out not just for its “futuristic” skyline but also for its efforts to reassert its ecological priorities. After significant mangrove losses due to aggressive development, Shenzhen’s mangrove recovery has been  “unprecedented.” This resurgence earned one of its wetlands a designation of international importance under the Ramsar Convention in 2022. The city’s approach to conservation, involving robust policy enforcement and community engagement, illustrates how urban areas can successfully integrate significant ecological habitats, reversing ecological decline in vulnerable delta regions.

Historical Ecological Decline

Shenzhen’s transformation from a quaint fishing village in 1979 into a bustling international metropolis epitomizes China’s rapid urbanization. As the country’s first special economic zone, it spearheaded economic reforms, but at a significant environmental cost. Extensive land reclamation for commercial and residential development drastically reduced mangrove habitats to a low of 50 hectares in 1991.

Left image: The view from Hong Kong’s Lok Ma Chau in 1979. Across the river, what will become the city of Shenzhen is still just fields. Photo courtesy of John Holmes / Alamy.

Right image: The same view today shows the rapid pace of urbanization, with Shenzhen’s high-rises looming over Hong Kong’s aquaculture ponds, known locally as gei wai. Photo courtesy of May Tse / South China Morning Post / Alamy.[/caption]

Shenzhen’s new development zone of Qianhai district, shown here under construction in 2010, is built almost entirely on reclaimed land. The city’s expansion has been at the expense of large areas of natural coastline, including beaches, mudflats and mangroves. Photo courtesy of Jacky Zhao /Associated Press / Alamy.

The introduction of non-native, quick-growing tree species like Sonneratia apetala intended as a quick fix for mangrove restoration and coastal stabilization, resulted in excessive growth and disrupted native biodiversity. This proliferation created destabilizing monocultures, obstructed flood discharge channels and increased waterlogging, complicating flood management efforts.

Restoration Efforts and Policies

Shenzhen’s 260 km-long coastline, fortified by mangroves, serves as the first line of defense against climate-related disasters. However, environmental stressors have undermined the coastline’s structural integrity, diminishing the protective role of the mangroves. 

Recognizing this vulnerability, the city authorities reversed course around 2020, embracing a strategic approach that included selective tree reduction. Haichao Zhou, an associate researcher at Shenzhen University, serves on the conservation panel that recommended a nature-based restoration plan. This strategy, focused on systematically removing fast-growing invasive species, was recently adopted by the local government.

According to the city’s 2023 environmental report, Shenzhen created 12.72 hectares and restored 13.08 hectares of mangroves in 2022 by selectively cutting fast-growing Sonneratia apetala. Although this resulted in a brief fall in overall mangrove cover, it facilitated the regrowth of native species, enabling them to recolonize the wetlands.

“Through careful management practices such as those adopted in Shenzhen, including judicious thinning, selective logging and maintaining suitable hydrological conditions, native species can naturally recover, enhancing mangrove diversity,” Zhou told Dialogue Earth.

Left image: The invasive Sonneratia apetala is a fast-growing species that crowds out native mangroves. Photo courtesy of KG Tagulao / Macau Biodiversity, CC BY NC ND.

Right image: Aegiceras corniculatum is one native species of mangrove that has been planted to replace removed Sonneratia apetala trees. Photo courtesy of KG Tagulao / Macau Biodiversity, CC BY NC ND.

Central to Shenzhen’s success in restoring its mangroves is an integrated management strategy, combining a unique governance model with strict regulatory measures. Since 2018, the enforcement of land reclamation bans, which prohibit new coastal reclamations, particularly around mangrove forests, have significantly contributed to their protection. 

The 2021 National Wetland Law further bolstered conservation efforts by providing a strong legal framework, which also prohibited unauthorized land reclamation, set “ecological redlines,” promoted mangrove restoration and sustainable use of wetland resources. The law mandates strict penalties for violations and underscores the importance of wetland biodiversity. In Futian district, mangroves have also proven effective in treating municipal sewage, demonstrating the multifaceted benefits of integrating natural ecosystems into urban infrastructure. Today, the city boasts nearly 35,000 hectares of wetlands, with 296.18 hectares reserved for mangroves. The largest concentration of mangroves, covering around 100 hectares, is found in the Futian Mangrove National Nature Reserve. It forms a critical ecological corridor, connecting fragmented mangrove areas across urban spaces, facilitating bird migration, improving their survival rates and serving as natural barriers against urban encroachment. 

Between 2000 and 2022, mangrove cover across Shenzhen Bay expanded significantly from 281.51 to 526.43 hectares, countering the global trend of mangrove loss.

With Hong Kong on its southern side, Shenzhen Bay is ringed with parks and nature reserves. Together, they play a crucial role in conserving and restoring this shared coastal ecosystem. Graphic courtesy of Dialogue Earth.

Multistakeholder Collaboration

East of the Futian Nature Reserve is the Futian Mangrove Ecological Park, a pioneering model of public resource management, highlighting the effectiveness of multistakeholder collaboration. Managed by the Mangrove Conservation Foundation (MCF) since 2015, it is China’s first government-mandated park managed by an NGO.

The MCF, founded in 2012 with support from 32 entrepreneurs and the Alashan Society of Entrepreneurs and Ecology – China’s first business-led nonprofit focused on conservation – features a governance model with publicly elected trustees, ensuring robust accountability and community involvement.

The Futian Mangrove Ecological Park includes peaceful green spaces for Shenzhen’s residents to enjoy as well as protected areas set aside for mangrove restoration. Photo courtesy of Dan Hanscom / Alamy.

Baohua Yan, the MCF’s secretary general, emphasized the foundation’s role in bridging conservation efforts between Shenzhen and Hong Kong, repurposing traditional fishponds, known as gei wai, into high-tide habitats for birds. “As gei wai aquaculture practices are no longer conducted in Shenzhen, fishponds now require adjustments and adaptations from the perspective of birds,” she told Dialogue Earth.

Inspired by techniques from Hong Kong’s Mai Po Nature Reserve, the restoration of gei wai fishponds in the Futian Nature Reserve has converted them into diverse bird habitats, leading to an additional population of 28 water bird species and 13,737 individual birds.

“Shenzhen Bay has limited wetland space, it is unlikely that developed areas will be reconverted into wetlands. Our actions are aimed at maximizing the ecological functionality of existing wetland resources,” said Yan.

Traditional gei wai ponds in the middle of the Futian reserve have been repurposed to make a more natural area of wetland that supports a wide variety of species. Photo courtesy of Liang Xu / Imago / Alamy.

Left image: In Hong Kong’s Mai Po reserve, a small number of gei wai have been preserved for their cultural heritage value. Constructed by dredging around stands of mangrove, the ponds were designed to let water in during high tide, capturing baby shrimp and fish. Photo courtesy of Katherine Cheng / Dialogue Earth.

Right image: Traditionally, shrimp and fish were only grown and harvested in the gei wai during the autumn and spring. At other times, the ponds were drained, creating areas of shallow water and exposed mud where wetland birds such as these egrets could feed. Photo courtesy of John Holmes / Alamy.

Lili Sun, founder and director of MCF, has championed this innovative social participation model “to strengthen conservation efforts and enhance public resource management.” 

The government oversees the park to ensure compliance with environmental policies and standards, providing support in funding, resources and technical assistance. This public-private partnership combines government oversight with NGO flexibility to achieve sustainable public resource management.

“Our work in managing the park and our involvement in community outreach illustrate the vital role NGOs play in bridging government efforts with public interest,” explained Sun. This engagement has increased local and visitor participation in birdwatching, leading to dedicated groups across Shenzhen. Today, Shenzhen boasts 10 provincial-level nature education bases, 22 nature schools and 27 nature education centers.

Birdwatchers gather on the northern shore of Shenzhen Bay to take photos of the many migratory birds that find winter refuge on its mudflats. Photo courtesy of Fenghuai Dong / Alamy.

Sun’s comments were echoed by Yuying Ouyang, a local volunteer and nature-based educator. She told Dialogue Earth that increased birdwatching has raised awareness about mangrove wetlands. For example, public opposition successfully halted a local, controversial 2020 tourism cruise dredging project, which threatened mangroves and migratory birds, demonstrating the vital role public awareness and nature education play in conservation efforts. “The public might have a different attitude towards cruise tourism without birdwatching and nature education,” said Ouyang. “They wouldn’t otherwise understand the significance of preserving a stretch of muddy flats.”

Assessing the Success of Restoration Efforts 

A key indicator of Shenzhen’s mangrove restoration success is the resurgence of the black-faced spoonbill population in Shenzhen Bay. Once critically endangered, this species now benefits from improved habitat conditions. “During the 1980s, the global population of black-faced spoonbills dropped to fewer than 300 individuals. However, concerted conservation efforts across their migratory range have proved hugely successful,” explained Qijie Zan, a mangrove expert from the Futian Nature Reserve. A 2023 census reported a record 6,633 of these birds globally, with Shenzhen Bay alone hosting 299, making it the world’s third largest habitat for the species.

Black-faced spoonbills forage around mangroves near Shenzhen’s Futian nature reserve. Photo courtesy of Liang Xu / Xinhua / Alamy.

Beyond wildlife benefits, mangroves offer critical ecosystem services such as coastal protection, carbon sequestration and water purification, contributing to climate change mitigation and resilience against natural disasters. According to one government report, every 100 hectares of mangroves in Shenzhen Bay absorbs nearly 4,000 tons of carbon dioxide annually. The rerouting of rain and sewage flow has improved water quality, increasing animal and microbial diversity and enhancing the ecosystem’s resilience against extreme weather events.

“Shenzhen’s comprehensive approach to environmental management has positioned it as a leader in urban sustainability,” said Ma Jun, director at the Institute of Public and Environmental Affairs (IPE), an environmental organization based in Beijing. Shenzhen has one of the lowest pollution rates in China. “Shenzhen’s initiatives have helped it perform very well on the [IPE] Beautiful City Index, underscoring the city’s role as a model for others to follow,” Ma added. 

Left image: Volunteers, including children and young people, gather for an event to promote the protection of Shenzhen’s rivers. Increased public awareness has played an important role in influencing government policy on habitat conservation. Photo courtesy of Fenghuai Dong / Alamy.

Right image: The Shenzhen authorities have made concerted efforts since the mid 2000s to reduce the amount of pollution entering Shenzhen Bay. For example, the Fengtang River, which runs through the Futian nature reserve, used to be lined with concrete. The reintroduction of plants along its banks has improved the quality of the water and helped reduce flooding. Photo courtesy of Hua-Lin Xu, “Environmental remediation promotes the restoration of biodiversity in the Shenzhen Bay Estuary, South China”,Ecosystem Health and Sustainability, CC BY

A positive side effect of a population invested in birds is the shift in public attitudes towards conservation, subsequently influencing government policy on habitat preservation. In June 2024, China’s National Development and Reform Commission released an action plan for migratory bird flyway protection and restoration, addressing critical challenges in southern China’s wetlands, including human interference, habitat fragmentation, degradation and invasive species. By 2030, the plan aims to protect 90% of habitats along migratory bird flyways by establishing a comprehensive national conservation network. 

There has been an increase in birdwatching that is not unique to Shenzhen. The number of birdwatchers across China has increased more than tenfold in the past decade, with the 2023 census putting the number of birdwatchers at 340,000, up from 20,000 in 2010. 

Lu Li, head of the Wild Bird Society, a Beijing-based birdwatching group, highlighted the growing impact of this trend. “As birdwatching becomes more popular, people’s attitudes towards bird conservation and habitat protection improve,” she said in an interview. In places like Yunnan, Jiangsu and Beijing, birdwatchers have played a significant role in shaping policy advocacy and planning. She told Dialogue Earth: “Now, when the government undertakes certain projects, there is an increasing consideration to preserve habitats for birds.” Ultimately, what benefits birds also benefits people.

Future Challenges to Conservation Efforts

Despite Shenzhen’s successes, multiple threats to its mangroves and bird populations remain. As the city expands, the pressure on natural habitats continues to intensify. One innovative solution has been the sponge cities policy which aims to address stormwater run-off in urban areas through green infrastructure, such as permeable pavements, green roofs, rain gardens and constructed wetlands. These measures help to prevent flooding and reduce pollutants that can harm waterways including wetlands and mangroves. Jianbin Shi, a wetland expert at the Paulson Institute, noted that across the Pearl River Delta “industrial wastewater is perhaps the greatest threat to wetlands.” In Shenzhen, birds also face risks from colliding into skyscrapers. Historically, land reclamations have been used to curb rising house prices, a temptation that could return with increasing population pressures, despite existing regulatory bans. Although for now, the opposite seems to be true. Despite beating expectations with 5.3% GP in 2023, China’s economic recovery remains unsteady. With fewer houses being sold, the government is now focussed on encouraging house buying rather than resorting to land reclamation.

Multiple threats to Shenzhen’s wetlands remain. “Continued efforts in public education and technological integration will be crucial for future success,” says IPE’s Ma Jun. Photo courtesy of Liang Xu / Xinhua / Alamy.

The long-awaited Shenzhen Wetland Protection Plan (2021-2035), which aims to enhance wetland protection and establish Shenzhen as an international wetland city, is still being drafted; a finalized version is not expected before July 2024. Making it available to the public will foster accountability and assist in strategic planning. Accelerating the timeline for the world’s first international mangrove center, to be built in Shenzhen in collaboration with Ramsar, would also help.

Addressing these challenges will better position Shenzhen to navigate the complexities of urban development while maintaining its commitment to mangrove protection. In the meantime, ongoing public engagement and education programs will help sustain conservation efforts, making environmental preservation a shared responsibility. The Futian Mangrove Ecological Park offers a template that promotes transparency, community participation and scalability for broader application in China and beyond.

Ma Jun emphasized the importance of continued commitment: “Shenzhen’s environmental strategy serves as a blueprint for sustainable urban development. Continued efforts in public education and technological integration will be crucial for future success.”