Baiji river dolphin illustration

The Yangtze River Dolphin, also known as the Baiji Dolphin (Lipotes vexillifer), was a white freshwater dolphin born in the Yangtze and Qiantang Rivers of China in the 1990s.

Baiji is best known for his squinting eyes and long, jagged, beak-like mouth. Lovers tell tales that it is the “goddess of the Yangtze”, a symbol of peace and prosperity and a protector of the people of the sea. But unfortunately, the creature disappeared more than two decades ago.

Read more: River dolphins are truly unique and endangered

Recent Yangtze River Dolphin sightings

After suffering a dramatic population collapse in the late 1950s when it began to be hunted for its meat and hide, the baiji became known as one of the world’s rarest mammal species.

It has not been seen in the Qiantang River today since the 1950s. And while scientists spotted at least 400 individuals between 1979 and 1981 in the Yangtze River, a survey in the late 1990s found only 13 animals.

The last record of a confirmed, authenticated sighting in the wild is from 2001 when fishermen found the corpse of a pregnant Baiji woman in the city of Zhengjiang. (Since then, several unconfirmed sightings by fishermen and others have surfaced.)

The only Yangtze river dolphin in captivity in the world – a male called Qi Qi — lived at the Institute of Hydrobiology in Wuhan, China for 22 years after being rescued from a fishing injury, and died in July 2002.

Baiji white dolphin: Functionally extinct

In 2006 when conservationists began a six-week survey of the entire Yangtze main channel where baiji had previously been found, they failed to find any evidence that the species survived.

So experts had to declare Baiji’s white dolphin “functionally extinct” — meaning that even if some individuals exist out there, the population is no longer viable.

Read more: How do we know when a species is extinct?

Baiji’s ‘crushing’ search

When the conservation team left the Chinese docks in 2006, they had two ships, each complete with a team of visual observers and acoustic equipment to listen for the dolphins’ whistles.

“As the survey went on, we saw finless porpoises, which are much harder to see, but we didn’t see or hear baiji,” says Barbara Taylor, a senior scientist at the Southwest Fisheries Science Center, who was part of the study team. “You know, the clock was really ticking and it got more and more depressing as time went on. It’s quite a soul-crushing experience.”

Since then, several other finless porpoise studies have been published, but there have been no confirmed sightings of baiji. “We’ve been waiting to really put, quite literally, the final nails in the coffin for a couple of years now,” says Taylor.

On the policy side, there is usually a long time between when researchers assume that a species is completely extinct and when politicians declare that species extinct.

The Romeo Problem

Most people are familiar with Shakespeare’s story of Romeo and Juliet. Taylor says the tragic end is a fitting illustration of the challenge of declaring a species extinct.

In Shakespeare’s tale, Juliet takes poison to fool people into thinking she is dead. Unfortunately, she misleads Romeo and he acts on this (false) knowledge and kills himself. Juliet then takes her own life, this time for real, after waking up to find her lover dead.

“If you declare them extinct, and they’re not actually extinct, and you remove all the protections that were in place, then you’re actually causing the extinction,” Taylor says of baiji or similar creatures facing extinction.

This creates a dilemma for conservation scientists who want to describe exactly what is happening to biodiversity.

“It’s really hard to say, especially with marine mammals that are hard to see, if there’s even one pair of them left in the world,” Taylor adds.

Did humans cause this extinction of white dolphins?

The question of whether this is the first time humans have directly caused the extinction of cetaceans is the headline of paper describing the scant findings in 2006urvey published in Biology Letters.

“We are forced to conclude that baiji is now probably extinct,” the authors wrote. “Unlike most extinctions of large animals in the historical era, the baiji was not the victim of active persecution, but of accidental mortality as a result of large-scale human impacts on the environment.”

Read more: Earth is on the brink of the sixth mass extinction

Why is Baiji the dolphin extinct?

Boat collisions and dam construction are partly to blame, but persistent unsustainable bycatch by fishing companies is likely to be the worst, according to the study.

Spinning hooks and similar fishing gear caused half of all known baiji deaths in the two decades after 1970. research suggestsand 40 percent of deaths in the 1990s were caused by electrofishing, a practice that literally stuns fish with electricity to catch them.

“When we went out and did the study in Yangtze, it was like doing a study in the middle of the freeway in Los Angeles,” Taylor says. “It’s just not a natural environment. It is heavily influenced by humans, so it has a whole list of threats [for dolphins].”

Baiji began to separate in its evolution from other river dolphins about 20 million years ago.

It developed some unique features, such as a stomach divided into three parts, which is not found in other dolphins. Thus with its disappearance we have lost all antiquity evolutionary branch it represents.

Failed conservation work

One strategy that may have helped save baiji is “ex-situ conservation.” This refers to removing a species from its natural habitat and attempting to breed its population elsewhere.

The researchers tried this with baiji, taking some dolphins into the Yangtze River’s oak ponds—bends of the river set aside as designated cetacean sanctuaries. But initial attempts don’t go as planned.

In the 1990s, for example, a dolphin left in a bottom lake died after becoming entangled in fishing gear that was not retrieved, according to the Natural History Museum in Great Britain.

Continued work on the project failed due to “inexcusable delays in action” and because international funds were virtually unavailable, according to Samuel Turvey’s book Eyewitness to Extinction: How We Failed to Save the Yangtze River Dolphin.

“When we went out to find the last badgers and get them into these old lakes, they were already gone,” says Taylor, who was recently in San Felipe, Mexico, conducting research on few vaquitas left — a critically endangered species of porpoise in the Gulf of California.

For the baiji, things might have been different if ex-situ conservation had started earlier, while large numbers remained in the wild.

“Of course, knowing what we know now, you have to start doing these things when there are hundreds of animals,” Taylor says. “I think there was a really good chance they saved Baiji.”

Read more: Which animals will become extinct? The 32 closest are often overlooked

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