A team of scientists in China turned to an unusual source to track the population of the long river of finless dolphins: ancient poetry. Sample writings in the past 1,400 years show that the Yangtze River has no wings (Neophocaena Asiaorientalis) The range has dropped by at least 65%, with most of the declines occurring within the last 100 years. The findings were detailed in a study published on May 5 in the journal Cell Press Current Biology And link biodiversity to the nearly two thousand years of Chinese culture.
“Our work fills the gap between the ultra-long-term information we get from fossils and DNA and recent demographic surveys. This does show the strength of combining art and biodiversity conservation,” Zhigang Mei, a research co-author and aquatic biologist at the Chinese Academy of Sciences, said in a statement. Mei grew up beside the Yangtze River and respected dolphins, and elders in his community taught that they were like spirits that could understand the weather and fish levels. Injuring mammals is also considered unfortunate.
The Yangtze River extends nearly 4,000 miles from the Tangera Mountains on the Tibetan Plateau. It reaches Shanghai's East China Sea. It is the longest river in Asia and the longest river in the world. Many poets wrote about the bodies of water in waters, including Emperor Qianlong of the Qing Dynasty. Since both poets and merchants rely on rivers and their tributaries for travel, many have glimpsed the Yantez finless dolphin. Dolphins are the only known freshwater spore in the world that once lived in most rivers.
Close-up of the “smiling” long-finned Confucius of Baiji Dolphinarium of the Institute of Aquatic Biology, Chinese Academy of Sciences. Image source: Wang Chaoqun.
“The Yangtze River finless dolphins are large compared to fish, and they are very active on the water, especially before thunderstorms when they are actually chasing the fish and jumping around,” Mei said. “This amazing sight is hard to ignore by the poet.”
In this study, the team systematically excavated through preserved poetry, dating back to 618 AD, and found hundreds of references to dolphins. According to Mei, the facts of freshwater mammals like the Yangtze River finless dolphins reflect so frequently the deep connection between people and ancient Chinese nature.
“One of the biggest challenges in this study is the large number of Chinese poetry there and every poet's style is so different,” Mei said. “We have to figure out the accuracy of the poet. Some people may really focus on realism, describing their observations. Others may be more imaginative, exaggerating the scale or behavior of what they see. So once we find these poems, we have to study the life and writing style of each poet to ensure that we become reliable information.”
The team compared the dolphin references in the poem with the historical records of the poet's life events. This helps them point out the chronological order and geographical location of dolphin witnesses. The results show that the Qing Dynasty (1636-1912 AD) had more than half of the dolphin poems, and 477 poems mentioned the finless peacock in Yangtze. The Ming Dynasty (1368-1644) ranked second with 177 poems, followed by the 38th and Yuan Dynasty (1271-1368 CE) of the Song Dynasty (960-1279 CE), and the Tang Dynasty (618-907 CE) had only five poems.
Illustrations of the Ming Dynasty woodcut printing of “sancai tuhui” (in English, outline of the Three Great Powers) compiled by Wang Qi (1573–1620), a collection of 49 poems about birds and animals. The poem meticulously documented the Yanz finless dolphin through morphological details, surface posture and maternal nursing behavior. Image source: “Sancai Tuhui” written by Wang Qi (1573–1620).
Next, over time, the team used the information from the poem to reconstruct the distribution of holes in the river. The clearest reduction in habitat range occurred in the past century, between the Qing Dynasty and the modern era. Since the Tang Dynasty, the dolphin range throughout the river has dropped by 33%. Positive dolphin ranges in tributaries and lakes also dropped by 91%.
Over the past 100 years, the sharp decline coincides with previous studies. This study attributes this trend to human changes to the Yangtze River, especially hydraulic engineering projects. The river is home to the world's largest hydroelectric facility (three canyons), which is a number of other projects that generate electricity but can potentially damage the flow of the river. Furthermore, dam buildings in the 1950s blocked their movement from the mainstream of the river, which may be why they disappeared from the lakes and tributaries of the Yangtze River. Over the past few decades, two other species of the Young family have endemic to Baiji Dolphin (Fat riskr) and Chinese pad fish (Psephurus Gladius) – The area has become functionally extinct, which may be due to habitat changes.
[ Related: Eavesdropping on pink river dolphins could help save them. ]
“Protecting nature is not only the responsibility of modern science; it is also closely linked to our culture and history,” May said. “Like poetry, art can really inspire emotional connections and make people realize the harmony and respect that we should have between us and nature.”
In future research, the team plans to return to the poems they collected to understand how they can find the verses about the appearance of the river, how big the Porpoise was once, and how they manifested. They hope this work will eventually help today's finless wingless Porpoise heal and inspire more scientists to gain ecological insights using poetry, novels, paintings and other historical art forms.
“This work has allowed me to rethink the scientific value of historical documents and show us the ability to think interdisciplinary,” Mei said. “Chinese poetry, this ancient art form, can be a serious scientific tool. Using the past to understand the present, the story behind the art, 'decode': not only research, it's like talking to poets of the past.”
