Words and images by Katherine Cheng | Website | Instagram

This story was originally published on China Dialogue under a Creative Commons license (CC BY ND NC). Also available in Chinese/中文.

Nestled deep within one of the many bays of the Pearl River delta, a densely populated region at the confluence of the Pearl River and the South China Sea, a rare patch of mangrove forest can be found hidden between the towering skyscrapers on the Hong Kong–Shenzhen border. Egrets laze in the sun as small crabs scuttle at their feet, a mountainous skyline of construction cranes looming behind them.

Mangroves are small trees that grow along the coastlines of more than 100 countries in tropical and subtropical regions. They were once widespread on the Pearl River delta and around the inlets and islands of the neighbouring Hong Kong Special Administrative Region (SAR). Now there are only about 60 small patches remaining in Hong Kong – the largest is at Mai Po, at the head of Deep Bay (also known as Shenzhen Bay).

Over the past 50 years, 50% of the world’s mangroves have been lost. This is due to a combination of factors, including coastal reclamation, urbanisation, unsustainable aquaculture practices and pollution.

Hong Kong is not exempt from these ecological stressors. With space limited, urban development looms ever on the horizon. This is clearly in evidence in Starfish Bay in the New Territories, where a new housing development towers over the beach. Long-time resident Mr So is only too aware of the issues: “There’s too much pollution, and look at all these new buildings that have been built nearby. It’s changed so much.”

The loss of mangroves means more than just the loss of another species of plant. Walking through the Mai Po Nature Reserve at low tide, it’s clear how important this ecosystem is. The tangled, gnarly roots are teeming with life, a haven between fish ponds and exposed mudflats.

Given the myriad threats to the Mai Po mangrove forest and all the actors in its ecosystem, Mai Po was designated a Wetland of International Importance under the Ramsar Convention in 1995, thereby helping to shield the forest and surrounding mudflats from damage. It is part of a Hong Kong success story, albeit a limited one, where after years of degradation, the mangroves are now making a recovery in the region.

Benefits of that recovery have implications far beyond a healthy ecosystem. Eddie Leung, assistant manager of WWF’s Mai Po Habitat and Infrastructure programme, explains that, when seen as a nature-based solution, the mangrove ecosystem “addresses coastal erosion, prevents typhoon damage, provides a rich nursery for biodiversity, and more recently, is known for storing carbon.” For people who live in low-lying areas, this means the trees not only help protect their homes from flooding, but also provide a source of income through the fish stocks they nurture.

To conserve mangroves, protected areas and restoration projects are vital. But for Hong Kong’s mangroves to continue to recover, and for these coastal forests to start making a come-back elsewhere – including on the Chinese mainland – best practice needs to be followed. Reserves need to be properly monitored and policed. And planting should only occur in areas suitable for mangroves, using only suitable local species.

What’s happening in Hong Kong shows there is hope for mangroves. But much more needs to be done if we want to prevent this vital coastal ecosystem from disappearing by the end of the century.