The Pink Dolphins of Hong Kong
Photo credit: All close-up photographs of the pink dolphins on this entry are the work of Thomas Tue, aka Mr. Dolphin, of the Eco Association Limited.
The Dolphin-Sighting Tour
On this bright late summer morning I got up at 6:30 and headed over to Tung Chung to meet with the group for a dolphin sighting tour. Eco Association Limited organized this tour with Mr. Thomas Tue, also known as Mr. Dolphin, as our guide. We met promptly at 9am, then walked over to the Tung Chung Development Pier. After boarding a new and air-conditioned junk, we headed out to the ocean at 9:40. The junk returned to the pier at 2pm.
I was very thankful for the air-conditioned interior of the junk. Other tours are not of this scale, they usually operate on small tour boats and certainly come with no air conditioning.
We first headed over to the waters off of the third runway of the Hong Kong International Airport. There we could see the Hong Kong-Zhuhai-Macao Bridge. And we certainly saw, from a distance, the pink dolphins of Hong Kong.
General Characteristics of Dolphins
Dolphins are mammals, and despite the clear differences they actually share many characteristics with human beings. First of all, they breathe through lungs. They are also warm-blooded animals. Finally, they give birth not by laying eggs, but instead bearing in their womb the baby dolphins until they are ready to come out and charge down the world.
Photos: Without foot-long lenses, this was the best capture of the dolphins with my iPhone 13 Pro. Again, all close-up photographs of the pink dolphins in this entry are the work of Mr. Thomas Tue, aka Mr. Dolphin, of the Eco Association Limited.
Because the dolphins breathe through lungs, they rise above the water in order to breathe. This is why we are able to do dolphin sighting, as they only show their faces when they have to breathe. Dolphins move their tail fins up and down for propulsion above the water in order to breathe. Their air vent is above their forehead. With each inhalation they can last under the water for a few minutes. As such, this determines the rhythm of the sighting.
There are more than thirty species of dolphins in the world. They eat fish, octopus and squids. The pink dolphins of Hong Kong eat mainly fish. They like these following fishes for their size: yellow croakers, gray mullets, yellowtails and Bombay ducks.
In terms of sharing similar characteristics as humans, the dolphins are also an intelligent animal. The key indicator is their ability to communicate via making ultrasounds in the ocean. Their melon is the organ that enables the making of these ultrasounds, which reach and then bounce off the sea floor. For more on the function of the melon for aquatic mammals, please see the Wikipedia entry here.
In terms of communication, like humans each species of dolphins living in different habitats will have its own language. The dolphins of one habitat are not able to communicate with the dolphins in another habitat.
Finally, dolphins have excellent vision. The water of the Pearl river comes with a lot of soil and sediments, so the dolphins are able to see their environments when they drive themselves up the water for breathing. They certainly see us in our boats, and we were told that we must remain quiet, otherwise the dolphins will not come close to us.
About the Pink Dolphins of Hong Kong
The scientific name for the pink dolphins of Hong Kong is Sousa chinensis. Its common English name is Indo-Pacific Humpback Dolphin. They are a vulnerable species with the protection of law in Hong Kong. In the last section of this entry, I will discuss sources that explain the situation of vulnerability for the dolphins.
The Sousa chinensis of Hong Kong is very special in a few respects. This kind of dolphins are also found in the seas south of Africa and north of Australia. The pink dolphins of Hong Kong live where the ocean meets the river. They move about in a limited area surrounding Lantau Island, where the mouth of the Pearl River is. They do not venture out to the open sea. On this tour, we did reach the waters at Fan Lau, overlooking Kai Yat Kok, which is the westernmost islet in Hong Kong.
Photos: Fan Lau and Kai Yat Kok, where some of the pink dolphins make home.
The pink dolphins of Hong Kong are the only dolphins in the world that bear the color pink. It is not that their skin is pink in color, but rather that their skin is very pale due to the habitat that they live in. At where the sea water and fresh water meets, the sediments of the river water prevents the dolphins from acquiring color from sunlight. Their skin is pale and shows the blood that circulates in their body, especially when their blood vessels expand during exercise. As such, the grown pink dolphins of Hong Kong are pink in color.
The coloring of their skin provides the key indication of their life stage. Grown pink dolphins are fully pink. If you see one with gray dots or patches, that means they are in their teenage. The gray pink dolphins are infants.
Photos: the color of the skin provides the key indication of the dolphin’s life stage.
At mating season, the male dolphins have to do much hard work. Some three to five males will gather and surround the one female, and the males have to swim a lot, and very fast to impress her. The term of pregnancy is ten months, and once the baby dolphin is born, the mother will raise it for all the life skills it needs to survive.
Usually at each sighting one can see three, five to seven of the dolphins, but recently more than ten could be seen.
Views of the Hong Kong Fishermen
It is believed that the Sousa chinensis have made it home in Hong Kong since the 17th century. Needless to say, they were familiar to the people of Hong Kong. A few written accounts have documented their existence, in both official, unofficial and Chinese and English sources.
The fishermen of Hong Kong do not think so highly of the dolphins traditionally. There are a few reasons. They believe that the dolphins are the reincarnations of the seamen lost at sea. They do not symbolize good luck. As a practical matter, the fishermen steer away from the dolphins when they fish because the dolphins will certainly drive away the fish.
A Habitat Threatened
The pink dolphins of Hong Kong are not oceanic dwellers. Because they live where the ocean meets the river, the waters of Tung Chung in southwestern Hong Kong are their only habitat due to the salinity of the water. In nowhere else are the dolphins found in Hong Kong, despite Hong Kong’s rich marine life throughout its territory. There are a few developments in Hong Kong that threatens the habitat for these dolphins.
It would not be surprising that a few well-known culprits have contributed to the dropping numbers of the pink dolphins. The large-scale development projects of the third runway of the Hong Kong International Airport and the Hong Kong-Zhuhai-Macao Bridge are believed to have caused an adverse effect to the only habitat for the pink dolphins in Hong Kong. After the construction phase of the bridge, the count of pink dolphins in that area dropped 20% as compared to the pre-construction years a decade ago (Ching Sze Ip). According to the Hong Kong Dolphin Conservation Society, “At least 45-50 dolphins routinely use the footprint of the third runway reclamation site as their main habitat, they are the direct victims.”
Furthermore, pollution due to the water and the sea traffic, along with fishing activities in the area, continue to affect the habitat for the pink dolphins. Some of these human activities have caused injuries to the pink dolphins.
About a decade ago, there were more than 100 pink dolphins living in the Hong Kong waters. A few years ago in 2018, coincidental to the completion and opening of the Hong Kong-Zhuhai-Macao Bridge, the count of the pink dolphins dropped to 32. It is believed that the most recent count is at 40, which is good news, but a far cry from the peak count twenty years ago.
Sources
On-site Introduction by the Eco Association Limited.
Ching Sze Ip, The Indo-Pacific Humpback Dolphins of Hong Kong— Not Much Time Left for the Mascot of the Handover? April 24, 2020, BBC Chinese News.
Hong Kong Dolphin Conservation Society, “30 Third Runway Victims Campaign.”
The Wikipedia on Melon (cetacean).
The Wikipedia on Dolphin.
The Wikipedia on Kai Yat Kok (Chin).
