Chinese White Dolphins in Hong Kong Face Alarming Decline

October 25, 2023[2]Chinese white dolphins in Hong Kong waters are facing a severe decline, according to a recent study released by the Chinese University of Hong Kong (CUHK). The study, which analyzed data from 1996 to 2020, revealed a dramatic drop in the population of these dolphins, from 158 in 2003 to only 37 in 2020. This represents a decline of over 76%, raising serious concerns about the future of these marine mammals.

The study, which focused on six waters near Lantau Island, identified several key factors contributing to this decline. These include habitat loss, water pollution, fishery activities, and frequent high-speed ferry navigation. The researchers highlighted that the most significant factor was the reduction in habitat due to large-scale land reclamation projects, such as the artificial island for the Hong Kong-Zhuhai-Macao Bridge and the expansion of the Hong Kong Airport.

Reclamation Projects Pose Serious Threat

Analysts believe that especially in the North Lantau area, the original habitat of dolphins has been greatly reduced due to large reclamation projects such as the artificial island of the Hong Kong-Zhuhai-Macao Bridge, the third runway of the Hong Kong Airport and the Tung Chung expansion. The study found that the living environment of dolphins in North Lantau Island is most significantly worse than that in South Lantau Island and other waters.

The study found that the increase in suspended solids and nitrogen content in the water is related to the decline in dolphin population, indicating that the accumulation of pollutants may change the marine ecological environment and even affect the dolphin’s food chain. The research also found that the reclamation project poses a serious threat to the survival of dolphins, which not only directly reduces their range of activities, but also affects the reproduction of marine organisms, gradually reducing the food sources of dolphins.

In addition, the frequency of high-speed ferry navigation also affects the behavioral patterns of dolphins, affecting their foraging ability, and at the same time increasing the risk of collision, threatening the survival of dolphins. Dr. Liang Peijian, a member of the research team, said that with rising sea water temperatures, intensifying pollution and expanding reclamation range, Chinese white dolphins in the waters of the North Lantau are facing unprecedented survival pressure.

Advocate the Expansion of Marine Protected Areas

The Hong Kong government has established marine reserves such as the North Lantau Coast Park in recent years, but studies have found that these measures have failed to effectively prevent the continued decline in dolphin populations. The research team suggested that Hong Kong should expand the scope of marine reserves, especially in the most affected North Lantau waters, to provide a wider shelter space to ensure dolphins can continue to survive.

The team also suggested that the driving range and speed of high-speed ferries should be further restricted to reduce the risk of dolphins colliding with ships, and at the same time reduce the impact of acoustic interference on dolphins foraging behavior; and suggested that the government should strengthen supervision of sewage discharge and reduce industrial and domestic sewage. Impact on marine ecology.

The decline in the Chinese white dolphin population in Hong Kong serves as a stark reminder of the broader environmental challenges facing marine ecosystems worldwide. In the United States, similar issues are observed in areas like the Gulf of Mexico, where the Deepwater Horizon oil spill in 2010 had devastating effects on marine life. The spill, which released millions of barrels of oil into the ocean, led to significant declines in various marine species, including dolphins.

In response to such crises, conservation efforts have been ramped up. For instance, the National Oceanic and Atmospheric Administration (NOAA) has implemented strict regulations to protect marine mammals and their habitats. These include measures such as speed limits for vessels in sensitive areas and restrictions on fishing practices that can harm marine life.

In Hong Kong, the situation is equally dire. The study’s findings underscore the urgent need for more comprehensive and effective conservation strategies. Expanding marine protected areas, reducing pollution, and regulating high-speed ferry navigation are crucial steps. Additionally, public awareness and community involvement can play a significant role in safeguarding these vulnerable species.

Dr. Liang Peijian, a member of the research team, emphasized the importance of these measures. “With rising sea water temperatures, intensifying pollution and expanding reclamation range, Chinese white dolphins in the waters of the North Lantau are facing unprecedented survival pressure,” he stated. “It is imperative that we take immediate and decisive action to protect these magnificent creatures and their habitats.”

As the world grapples with the impacts of climate change and human activities on marine ecosystems, the plight of the Chinese white dolphins in Hong Kong highlights the need for global cooperation and sustained effort. By learning from successes and failures in conservation, we can better protect marine life and ensure the health of our oceans for future generations.