A few weeks ago, I hopped on a junk and went looking for dolphins. We had some great sightings in the Sha Chau and Lung Kwu Chau Marine Park, but equally memorable were the threats to these beautiful creatures: contaminated mud pits, high-speed ferries, trawlers scouring the seabed, and the site of the new bridge to Zhuhai and Macau.
The Pearl River estuary is home to around 2,500 Chinese white dolphin, the largest known population in the world. Within Hong Kong, there are essentially three measures to protect them. The Wild Animals Protection Ordinance prevents the hunting of dolphins. There is also the 1,200-hectare marine park north of the airport. Finally, but most importantly, is the Environmental Impact Assessment Ordinance, which requires environmental impact of developments to be minimised or mitigated.
These measures are not sufficient to prevent dolphins from going into decline, or even extinction, in our waters. A major underlying issue is that we know little about how much room dolphins need to survive and prosper, and how much pollution and other threats they can withstand. There are also no specific management objectives to assess fluctuations in the dolphin population, or evaluate the impact of new developments. We cannot wait for a catastrophe to address these issues.
Dolphins, like any other animal, can only take so much disturbance. Indeed, it is almost miraculous that they have held on in such numbers given the disturbance and devastated estuarine ecosystem they inhabit. The species' only chance to survive and prosper is to implement a management plan specifically designed to achieve this. This would empower the Agriculture, Fisheries and Conservation Department to act to reduce threats.
High-speed ferries are an excellent case in point. From 1999 to 2010, the number of trips across the Pearl River estuary rose by nearly half to over 170,000. Yet, no one in government has seriously questioned the impact on dolphins and acted to reduce it.
We must upgrade our approach, and use the available data and latest scientific analyses to better understand what the dolphins need to survive. Such an analysis would form the basis for a management plan, and provide impact assessment benchmarks.
