Ancient Chinese poems provided insights into the decline of the critically endangered Yangtze River's finless porpoise. A team of scientists analyzed over 700 poems dating back to 618 CE to trace how the habitat range of the porpoise changed over the past 1,400 years, revealing a 65 percent reduction, particularly in the last century.
According to Scientific American, the research team turned to ancient poems because official records rarely mentioned the Yangtze finless porpoises. The team manually verified each mention to ensure it referred to the porpoise and not other animals. Among the researchers was ecologist Yaoyao Zhang of the Institute of Hydrobiology at the Chinese Academy of Sciences. "Having access to past data allows us to detect when declines began and correlate those changes with potential threats like habitat destruction, climate change, overhunting, disease or the introduction of invasive species," Zhang said, according to Scientific American.
The study found that references to the porpoise increased over time, from just five mentions during the Tang Dynasty (618–907 CE) to 477 in the Qing Dynasty (1636–1912 CE), with over half of the total porpoise poetry found in that period.
By analyzing the geographical and temporal data from the poems, the researchers tracked the decline in the porpoise's habitat. Phys.org reported that the distribution area of the porpoise among the tributaries and lakes that feed into the Yangtze River declined by about 90 percent, leading to its disappearance from these areas. "The researchers found that the sharpest habitat-range decrease of the Yangtze finless porpoise occurred over the past century," according to Phys.org.
This decline aligned with increased human activity along the Yangtze River, including the construction of dams and habitat destruction. The Yangtze River is home to the largest hydroelectric facility in the world, the Three Gorges Dam, among numerous other projects that generate electricity but can disrupt the river's flow, reported Popular Science. "The decrease in dolphin numbers is especially due to the construction of dams, which have restricted their movement in the river and its tributaries," according to Phys.org.
The Yangtze finless porpoise is critically endangered, with about 1,250 individuals estimated to be living in the wild due to habitat loss. According to Scientific American, the species is native to China and faces severe threats from human activity.
The study highlighted the importance of combining historical literature with modern conservation efforts. "This amazing sight was hard for poets to ignore," said Zhigang Mei, a study co-author and hydrobiologist at the Chinese Academy of Sciences. Mei grew up along the Yangtze River, where the finless porpoise is an important part of the local culture. "We are connecting 2,000 years of Chinese culture with biodiversity," Mei said.
The researchers hoped their work would inspire others to use ancient sources to study natural changes and contribute to the recovery of the Yangtze finless porpoise population. "Our work fills the gap between the long-term information we obtain from fossils, DNA, and population studies. And it demonstrates the power of combining art and biodiversity conservation," Mei said.
"The authors plan to reexamine the poems to learn about the size of porpoise groups and their behavior before their numbers dwindled," reported Popular Science.
"Protecting nature isn't just the responsibility of modern science; it's also deeply connected to our culture and history," Mei said, according to Phys.org. The researchers utilized the poems not only to map the historical range of the porpoise but also to understand human perceptions of the animal throughout history. The Yangtze finless porpoise is known for its intelligence and charismatic appearance, looking as though it is always smiling—a trait that seems to mock its tragic fate.
Historically, the porpoises held a special place in local culture. Elders in Mei's community taught that the Yangtze finless porpoises were like spirits, predicting the weather and fish levels, and that harming them brought bad luck. Mei emphasized the importance of interdisciplinary approaches in conservation. "This work made me rethink the scientific value of historical literature and showed us the power of thinking across disciplines," he concluded.
"The researchers hoped that by drawing attention to the deep historical connection between people and the Yangtze finless porpoise, more attention would be drawn to its conservation. 'Art, like poetry, can really spark an emotional connection, making people realize the harmony and respect we should have between people and nature,' Mei said.
The article was written with the assistance of a news analysis system.