Endangered Dolphins

During my research for dolphin information I came across something very unusual. I saw a picture of a pink dolphin, yes that is correct, an actual pink dolphin. I read more about the Pink Dolphin and found out it was endangered, I decided to include information on this unique animal in my web page.

Pink Dolphin

Scientific Name: Sousa chinesis (Chinese White Dolphin)

In Hong Kong's scenic western harbor, a population of around 120 Indo-pacific Humpback Dolphins, or Chinese White Dolphins are fighting to survive against barrage of threats: pollution, habitat loss, over fishing, and boat traffic.

pink dolphin

As you can see from the picture, these dolphins are pink. People who have seen both say they're even pinker than the South American Boto. Although Sousa chinensis is found from South Africa to North Australia, this coloration is unique to Southeast Asia.

What kind of dolphins are these?

These dolphins can be found in geographically isolated populations from South Africa to Australia and up the Chinese coast to the Yangtze River. The populations in Southeast Asia are unique in their coloring: born almost black, they quickly change to light grey, then slowly become white or pink as the grey coloration recedes.

Where are they?

The Chinese White Dolphin is almost always found near coastlines, and usually near a major river mouth. The Pearl River provides the brackish (estuarine) water favored by this population. Young males may wander quite far from the group, but the population as a whole is unlikely to move to another location, no matter how degraded the environment becomes.

This population is usually found to the north of Lantau Island, and occasionally to the southwest, near the Soko Islands, and the southeast, near Peng Chau. The western, northern, and southern extents of their range are not known, though pink dolphins have been sighted around Macau.

How many dolphins are there?

Estimates range from fewer than 100 to around 150.

Why is the pink dolphin pink?

Not a lot is known about the dolphin's coloring because of their remoteness and rarity. It has been speculated they are pink for the same reason as pink flamingos. Like the dolphin, these marshland birds are not born pink but turn this color as they get older. A red pigment found in the muscle tissue of the crabs and shellfish theyear colors the flamingos. The colored molecule is not digested, yet is still absorbed in the birds' gizzard and accumulates in the shafts of the birds' growing feathers. Although this pigment is not visible in the raw meat of crustatia, it is the same pigment, which causes a prawn to turn pink when cooked.

Often flamingos in captivity are fed shellfish rich in this pigment in order to brighten their colorful appearance and heighten their appeal. Because the pink dolphin also feeds on these animals in the marshlands and flooded planes of the Amazon basin it is thought the same pigment accumulates in its skin as it gets older. I realize that now I am talking about the Pink Dolphin of the Amazon, however the have the same characteristics and coloring of the Chinese White Dolphin, just a different geographical location.

Size and Weight:

Males grow 8.4 feet and weigh 345 pounds. Females grow 6.6 feet and weigh 217 pounds.

Lifespan:

Has not been determined . Based upon their size, some scientists believe they live as long as 35 years.

What's killing the dolphins?

Reclamation	Construction of the new airport at Chep Lap Kok and the North Lantau Expressway have destroyed pristine natural coast and shallow marine habitat. More dolphin habitat will disappear when container terminals are built on reclaimed land at Yam O and Lung Kwu Tan, both areas frequented by the dolphins. Contaminated mud from reclamation is dumped in the seabed just north of the new airport platform.

Sewage	Some 150,000 cubic meters of raw sewage (screened, not treated), is dumped into the western harbor area every day. This is scheduled to 700,000 cubic meters a day by the year 2010. Sewage includes household toxic wastes such as cleaning fluids, bacteria, and viruses that can affect the dolphins directly, and industrial effluent.

Organochlorines	DDT (a pesticide still used in China) and PCBs (used in the electronics industry) from unidentified sources have been found in tissue samples from the dolphins in very high concentrations.

Over-fishing	Hong Kong's increasingly sophisticated and virtually unregulated fishing fleet is depleting the dolphins' food supply. Hong Kong's fish catch peaked in 1989. Several dead dolphins have show signs of having been caught and/or tangled in fishing nets.

Boat traffic	While dolphins are usually adept at sensing and staying out of the way of boats, some show signs of collisions. The Urmston Road shipping channel, with up to 70 vessels an hour, passes right through areas where dolphins are frequently spotted. (National Marine Mammal Laboratory)

Two pink dolphins