China's baiji dolphin, or Yangtze River dolphin, is listed as critically endangered, but scientists say it may already be extinct. In 2006, scientists from the Baiji Foundation traveled up the Yangtze River for more than 2,000 miles equipped with optical instruments and underwater microphones, but were unable to detect any surviving dolphins. The foundation published a report on the expedition and declared the animal functionally extinct, meaning too few potential breeding pairs remained to ensure the species' survival.
The last documented sighting was in 2002, but in October 2016, a team of amateur conservationists claimed to have seen the creature near the city of Wuhu in China's Anhui province. "No other creature could jump out of the Yangtze like that," team leader Song Qi told the Chinese website Sixth Tone. "All the eyewitnesses — which include fishermen — felt certain that it was a baiji." However, the team wasn't able to photograph the dolphin and had no other conclusive proof of its existence. Plus, none of the people who witnessed the sighting were experts on the animal.
The decline in the baiji dolphin population is attributed to a variety of factors including overfishing, boat traffic, habitat loss, pollution and poaching. Deemed "the goddess of the river," the dolphin's skin was highly valuable and used to make gloves and handbags.