Biodiversity refers to the degree of abundance of living things at ecosystem, species and genetic levels. A high degree of biodiversity indicates a rich ecology, which is hard to recover once damaged. Hong Kong's land area is only 1,100 square kilometres, due to climatic and geographical limitations, yet we have a very high degree of biodiversity that may seem out of proportion with the area. Overall, awareness and appreciation of local biodiversity is still low in Hong Kong, even though much controversy may arise when individual "star" species are affected by large development projects. In fact, rapid development in the last few decades has drastically reduced the native species populations, and damaged natural habitats. The Convention on Biological Diversity is an international agreement, and – through China – Hong Kong is among the signatories. We have to formulate proper conservation measures tailored to local needs. Later, the HKSAR government will release a Biodiversity Strategy and Action Plan.
More than 2,100 species of native plants, 997 saltwater fishes, 185 freshwater fishes, 520 birds, 236 butterflies, 117 dragonflies, and 86 reptiles have been recorded in Hong Kong. In some of these categories we even have more species than other countries that are much larger than Hong Kong. And some species are unique to Hong Kong. We do have very high biodiversity. Unfortunately, numerous precious species, including freshwater fishes and turtles, orchids and dolphins, have been declining in the past dozen years; some have even vanished from the wild. There are many factors threatening local biodiversity; the most direct and severe is the disappearance of natural habitats.
Demand for land for buildings and infrastructure is huge in Hong Kong. Large scale developments often put eye rural areas. For example, in the 1980s, the development of Tin Shui Wai new town led to the destruction of a large area of fish ponds, which comprised a very important wetland habitat. In the 1990s, construction of the 12.5-km North Lantau Highway – which crosses the whole northern coast of Lantau – damaged large areas that were home to Pitcher Plant (Nepentes mirabilis), an uncommon insectivorous plant that is protected by the Forestry Regulations. In the new millennium, construction of West Rail destroyed extensive farmland and threatened the rare fish Rose Bitterling (Rhodeus ocellatus) in a nearby stream. The latest Third Runway project of the airport will greatly shrink the habitat of Chinese White Dolphins (Sousa chinensis) and inevitably impact their population.
For development on private land, it is most difficult to assess the impacts on the environment and biodiversity. For instance, Tai Tong in Yuen Long was once a dragonfly hotspot—there was even plan to list it as a Site of Special Scientific Interest. However, the private land by the river of the country park was turned into a theme park, and the dragonfly hotspot disappeared forever.
Areas such as Green Belt are supposedly better protected by urban planning regulations and the Outline Zoning Plans. Yet government and landowners can still change the land use by following official procedures. Currently, the government is attempting to convert several Green Belt zones into housing areas. In one of these zones near Lion Rock Country Park, we can find Big-headed Frog (Limnonectes fujianensis), an uncommon species, and Lesser Spiny Frog (Quasipaa exilispinosa), which is globally ranked Vulnerable to extinction. If the change of landuse is permitted, the survival of these species will be in jeopardy.
Over harvesting and collection pushes species towards extinction
Water pollution also puts marine and river biodiversity at risk. Kam Tin River, originally an ecologically rich natural stream, has become a breeding ground of Blood Worm and Golden Apple Snail (Pomacea canaliculata) due to pollution by livestock waste, rural domestic wastewater and industrial sewage. On the other hand, river works also damage many natural habitats and result in the reduction of freshwater fish populations.
Over harvesting and over collection leads to the extinction of individual species, such as Three-stripped Box Turtle (Cuora trifasciata), which supposedly has high medicinal value. This turtle can hardly be found in the wild in Hong Kong today. Buddhist Pine (Podocarpus macrophyllus) and some species of orchids are also targets of collectors due to their popularity in gardening markets. Again they have almost vanished from the countryside.
Foreign species and climate change are also causes for concern. Global transportation and trade bring foreign invasive species into the local scene. Outside their native lands, these species lack their natural enemies and can spread rapidly and affect local biodiversity. In Hong Kong, the most obvious examples are Mile-a-minute Weed (Mikania micrantha), Golden Apple Snail (Pomacea canaliculata) and Tilapia (Tilapia spp.). Mile-a-minute Weed attaches to other plants and smothers them to such an extent that the original plants may die. Golden Apple Snails consume all aquatic plants, and Tilapia feed on all other species in the water. As for climate change, although it is a global problem it threatens species distribution and survival of individual regions, partly due to extreme weather. For instance, coral populations in Hong Kong have experienced more die-offs due to the change in sea temperatures.
Law failing to regulate development
There are legal protections for species as well as habitats in Hong Kong. The Forestry Regulations (Forests and Countryside Ordinance (Cap. 96A) protects 27 rare local plants; the Wild Animals Protection Ordinance (Cap. 170) protects most wild mammals, all wild birds, some reptiles and amphibians and two swallowtail butterfly species. The Country Parks Ordinance (Cap. 208) and Marine Parks Ordinance (Cap. 476) protect specific sites. Sites of Special Scientific Interest are designated for places with unique flora and fauna, geographical or geological features. The Environmental Impact Assessment Ordinance (Cap. 499) aims at avoiding, minimising or mitigating developmental impacts on the environment (including ecology). The Town Planning Ordinance (Cap. 131) offers protection to land and coastal habitats by setting landuse restrictions. The marine environment is protected through the Fisheries Protection Ordinance (Cap.171).
With all these law in place, local species and habitats should be properly protected. Yet in reality they are not. The Convention on Biological Diversity was extended to Hong Kong in mid 2011. The government must formulate a Biodiversity Strategy and Action Plan under the convention within this year. The Environment Bureau and the Agriculture, Fisheries and Conservation Department have set up different committees and focus groups, with members from green groups, universities, private and public sectors, district organisations and representatives from bureaus and departments. After a year of discussion, a proposal will be made for a 2015-2020 action plan covering aspects of species and habitat conservation, a review of the law, enforcement and public education.
In recent years, the Development Bureau, developers and economists have frequently tabled proposals to build houses on country park land. This reveals a lack of appreciation of local biodiversity on the part of officials and people in power in our society. If this is the case, even more international conventions or more committees will not work. Priority must be placed on protection of biodiversity, and correcting the misguided notion that biodiversity conservation is a roadblock to development. Only then can any conservation measures be effectively enforced.
No matter how modern or high-tech a city may appear, people's livelihoods and their basic needs of air, water and food all rely directly and indirectly on natural ecosystems. Hong Kong is no exception. Ecosystems involve all kinds of species, and the disappearance of species cannot be recovered with even more high-tech solutions. It is only when biodiversity is protected that our natural environment and ecosystems can be sustainably developed.
Text | Henry Lui & Dr. Cheng Luk-ki