When the "bai ji", or white Yangtze River dolphin, was declared functionally extinct in 2007, the last surviving mammal in the Yangtze River became the finless porpoise (jiang tun), fondly known as the river pig because of its rotund appearance.

Now the river pig, once revered as a river god and predictor of weather and guide to good fishing, is on the verge of extinction.

The urgency of the problem has been highlighted by the discovery of 10 dead mammals, commonly called river dolphins, since March 3 in Dongting Lake, according to the Fishery Affairs Management Station (FAMS) of the Animal Husbandry and Aquatic Products Bureau of Hunan's Yueyang City.

Another six have been reported dead since the beginning of this year in east China's Poyang Lake in Jiangxi Province, according to the provincial fishery bureau.

The discovery and disturbing photos of dead mammals, including an unborn fetus, caused public indignation and demands for the government to act. Last weekend the provincial government said it would relocate the dolphins to a safe part of the lake, China's second largest.

No one knows when that will begin and time is running out for the dolphins.

Today only around a thousand live in the Yangtze River basin, including around 80 in Dongting Lake and some in Poyang Lake, China's largest freshwater lake, in Jiangxi Province. Chinese scientists say they will be extinct in around 15 years, decreasing by 5-6 percent a year.

Initial postmortem findings indicated that the animals had not eaten in a long time, and at least two were starving, signaling habitat damage and lack of food. One female was pregnant and one animal had been severely injured by a boat's propeller.

The common causes of endangerment are human activity: fishing with dynamite and electric current, draining of habitat, dredging, river traffic, and pollution that includes toxic industrial discharge.

The river pig has long been considered a signal of coming storms because it makes small repeated leaps in the air, known as "saluting the wind" by fishermen. They know it's time to tie up their boats. The appearance of the finless porpoise, also signals good fishing sites.

Since 2006 scientists have been unable to find any trace of the "bai ji," the white Yangtze River dolphin, a species with fins. In 2007 the 25-million-year-old species was declared functionally extinct.

Human activity has so degraded the environment that the dolphins of any kind cannot survive long in Chinese rivers and lakes. Freshwater dolphins are rare anywhere in the world.

The river dolphin, also around 25 million years old, looks similar to a sea dolphin, but it's darker gray in color and lacks a dorsal fin. Adult males can be almost 2 meters long and weigh as much as 220 kg - but these dolphins were hungry and sickly.

The mammal is highly intelligent and is said to have an EQ as high as that of a chimpanzee. Like other dolphins and porpoises it appears to have a "smiling" expression and is friendly by nature. But they don't have anything to smile about anymore.

Biologist Wang Kexiong, with the Institute of Hydrobiology under the Chinese Academy of Sciences, blamed the deaths in general on increasingly busy shipping, uncurbed fishing, water pollution and other human activities. He has been monitoring the Yangtze River dolphin for years and took part in the postmortem exams of two of the dead dolphins from Dongting Lake.

The exams showed there was no residue of food in their digestive systems, suggesting they had struggled to find food long before they actually died. One was carrying a nine-month-old fetus, two months short of term. A photo posted online showed the fetus partly exposed after falling out of the mother's body, both lying in rubbish on a lake bank. People who saw the photo said they were heartbroken.

"It's devastating to witness such a smart animal with an angel's smile dying in such a painful way," commented one Internet user on Sina weibo.

Biologist Wang also discovered a fish inside the mouth of another dead dolphin. One suggestion is that the starving animal finally caught a fish but was too weak to eat it. Another suggestion is that the dolphin was the victim of banned fishing with electric current in which whole areas of the lake are electrified so fish are electrocuted. In that case both the fish and dolphin were electrocuted.

Electrocution

Though this method is banned, as is use of dynamite, some fishermen still electrify the water, netting the big fish and leave smaller electrocuted fish behind. This damages the fish stock because young fish cannot survive, in contrast to traditional fishing methods in which small fish slip through the net mesh.

Industrial pollution and pesticide runoff is also killing fish and the plants they feed on, thus, the dolphins at the top of the food chain don't have enough fish to feed on.

Ships pose another danger since engine noise from shipping traffic can overwhelm dolphins' sonar system, causing them to lose their bearings and collide with ships or run aground.

One of the two dead dolphins examined had suffered a deep propeller cut in its head.

Unlicensed sand dredging is rampant, damaging riverbeds and narrowing the dolphin's living environment.

He Daming was a fisherman for more than 30 years and is now one of the volunteers trying to protect the dolphins.

River dolphins need to breathe fresh air through their lungs when the air pressure falls ahead of a major storm. So when the dolphins make frequent appearances and jump out of the water, it's a warning sign that a storm is on the way and fishermen head home.

"They were called the God of the River by our ancestors," the ex-fisherman said.

He and 10 other volunteers patrol the lake by boat three or four times a day. They look for signs of dolphins, rescue injured or grounded animals and try to persuade people to halt harmful fishing and sand dredging.

But they have no enforcement powers and most people won't halt earning an illegal livelihood for the sake of dolphins. So volunteers can only report violations to wildlife officials.

In 2000, Yueyang City, where Dongting Lake is located, applied to the Hunan provincial government to declare the lake a protected habitat for dolphins. Approval would have meant continuous funding and crackdowns on illegal fishing and dredging.

Nothing has happened for the past 12 years, mostly for bureaucratic reasons. Meantime, the dolphins have been dying.

Early this year, the government erected a stone marker saying dolphins are a protected lake species.

"But it's only a stone tablet, that's all," said a frustrated volunteer, saying volunteers' efforts were limited because funding was limited.

So far there is no effective official campaign to save the dolphins.