By JIANG FUMEI
By JIANG FUMEI
WITH a round head, slightly convex forehead, and upturned corners of the mouth, the Yangtze finless porpoise, which is rarely seen now, has colloquially become known as a “smiling angel.” In 2013, it was included in the red list of critically endangered species by the International Union for Conservation of Nature (IUCN), and also listed as an endangered species in the appendix I of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora – also known as the Washington Convention). As the only surviving mammal in the waters of the Yangtze River, it was listed as an animal under first-grade protection at the state level in 2017.
The Yangtze finless porpoise.
On April 11, 2018, Professor Yang Guang and his team from the School of Life Sciences of Nanjing Normal University published a research report in Nature Communications. The finding of this study is that the Yangtze finless porpoise and its close relative, the marine porpoise, have enough significant and stable genetic differences to label them independent species – which increased the number of cetacean species in the world from 89 to 90. Furthermore, this has also raised the importance of protecting the Yangtze finless porpoise.
Lovely Water Elves
The Yangtze finless porpoise is a small cetacean animal, which looks similar to a dolphin. For the most part, its head is blunt but has a slight frontal bulge near its forehead. The porpoise has a short, wide rostrum, accompanied by small teeth and small eyes. There are no dorsal fins on its spine, and its fins are large and triangular. Their back has a 3-4 cm wide ridge in place of a dorsal fin and most of its body is covered in horny scales. Its body is gray or grayish-white and its abdomen is lighter in color compared to the rest of its body. The finless porpoise has a body length of about 1.2 meters, with the longest reaching 1.9 meters, and a body weight normally no more than 200 kilograms.
These animals are mainly distributed in the middle and lower reaches of the Yangtze River, especially in Dongting Lake, Poyang Lake, and the mainstream of the Yangtze River. They often appear in the section of the Yangtze River between Nanjing and Shanghai, where they feed on fish and shrimps. With a deep river, abundant fisheries, and aquatic animals, these finless porpoises love to hunt and hangout here.
Finless porpoises enjoy splashing around in the water. Their body allows them to roll, jump, nod, spray water, and make sharp turns. If they are frightened, they will swim quickly and then jump above the surface of the water several times in a row. With only their tail propelling them, they can lift their entire body out of the water, reaching a height of 0.5 meters.
These animals sometimes swim alone, but more often than not, they swim in pairs, especially when males and females chase each other. Sometimes, female finless porpoises also swim with its baby, providing safety in the open water. The finless porpoise also likes to swim alongside the ships and boats in the Yangtze River. The waves made by the powerboats disturb the usually calm water, causing the porpoises to chase the waves. People on the boats are so excited to spot the finless porpoise swimming.
The breeding season begins in autumn, roughly from September to October. However, its delivery period is roughly in the same month next year, which means it takes a whole year to breed a small finless porpoise. According to reports, the life span for these animals can be as long as 20 years. However, finless porpoises need to wait at least a day from the start of the signs of birth until the actual delivery. The delivery process lasts for nearly three hours. A 1992 study showed that the annual fertility rate of the finless porpoise is about 20 percent, and their sexual development starts at the age of four. Finless porpoises generally give birth to a single cub.
Female finless porpoises often take care of their calves by guiding them while they learn how to swim, as well as carrying them on back to surface every a few minutes to take in fresh air. Sometimes male finless porpoises also participate in rearing the calves, allowing the young to swim between the father and mother. The family will swim up and down in the water at the same time. Female finless porpoises tend to be very motherly. If the cub is unfortunately caught by poachers, the mother also tends to be caught because she will not abandon her cub.
Protecting the Endangered
Finless porpoises are sensitive to the changes in air flow above the surface of the water. When heavy winds and rains are approaching, they will become more active. They chase after each other close to the water surface, causing ripples and small waves. Local fishermen will then know that strong winds or torrential rains are coming if there are large numbers of finless porpoises, which is a very rare sight. This indicates an urgent warning – a huge storm is on its way! According to records, the most finless porpoises ever seen together was 87.
The significant decline in the number of finless porpoises began in the 1980s. The emphasis on the protection of finless porpoise began in 2006. This year, scientists attempted to conduct a comprehensive study of another mammal,the Chinese Baiji dolphin, or Lipotes vexillifer, but no Baiji dolphins were found. The following year, it was declared “functionally extinct.”
The finless porpoise also faces the same danger as the Baiji dolphin, with its population drastically reduced over the last decade or so. The noise and propellers of high-density, busy shipping vessels on the Yangtze River have become the biggest threat to their survival. Heavy fishing and the massive use of illegal fishing gear, water pollution, and the construction of water conservancy facilities, also threaten their survival.
In 2012, scientists discovered that there were only about 1,000 Yangtze finless porpoises left, and the population had decreased at an average annual rate of 13.7 percent. A prediction made by the Institute of Hydrobiology, the Chinese Academy of Sciences suggests that the species could vanish from the wild within a decade if no timely and effective protective measures are taken.
Today, there are eight Yangtze finless dolphin nature reserves in China, and a large number of volunteers have joined in the observation and conservation activities of the Yangtze finless porpoise. Since 2013, a seasonal fishing ban has been implemented along the Yangtze River.
From 2017, experts proposed suggestions for a comprehensive fishing ban in the Yangtze River basin. Other efforts include shutting down many large polluting enterprises, while the remaining enterprises have adopted more stringent environmental protection measures. In addition, stricter and more detailed environmental impact assessment and control system has been applied to new water conservation projects and shipping activities. With the implementation of those measures, the living environment of the Yangtze finless porpoise has been significantly improved, while ecological restoration work has also started. At the same time, Chinese scientists have mastered the artificial breeding technology of the Yangtze finless porpoise. Now, some Yangtze finless porpoises have been relocated to nature reserves and so far, everything goes well. Although the ecological protection of water areas is challenging, China hopes that the Yangtze finless porpoise will one day return to its once populous numbers.
JIANG FUMEI is a Beijing-based freelancer.