This year I took part in a winter survey of Poyang Lake’s finless porpoises, organised by The Nature Conservancy's Yangtze and Fresh Water Project. The study lasted for a week at the end of January, and was carried out by the Wuhan-based Institute of Hydrobiology of the Chinese Academy of Sciences. On Poyang Lake, I witnessed the shocking effects of large-scale sand dredging, which is threatening the survival of the finless porpoise.
It now seems possible that the finless porpoise, known in Chinese as the “river pig”, may go the same way as the baiji (the Yangtze River dolphin). In December 2006, a survey of the middle and lower reaches of the Yangtze River found no trace of the baiji, and the number of finless porpoises living in the Yangtze River is now also plummeting. Meanwhile, the Yangtze River basin’s ecosystem is suffering from the effects of shipping, sand dredging and over-fishing.
Urgent action is needed to save the finless porpoise, underlines Wang Ding, deputy director of the Institute of Hydrobiology. “There are between 700 and 900 finless porpoises in the Yangtze River itself, with about another 500 in Poyang and Dongting Lakes,” said Wang. “An optimistic estimate would put numbers at no more than 1,400 – less than half of the 1997 population. But although the porpoise population is currently dropping at a rate of 7.3% per year, it still has a hope of survival – if enough action is taken.”
Sand dredging has become a mainstay of local economic development in the last few years, and is an important source of fiscal revenue in the region that borders Poyang Lake. But at the same time, high-density dredging projects have been the principal cause of the death of the local wildlife population.
On January 26, the porpoise survey team braved the cold and boarded a giant dredging ship – known as the Dredging King by locals – that was anchored on Poyang Lake. A foreman told us that the Dredging King could dredge up hundreds of thousands of tonnes of sand every day. In summer and autumn’s high-water season, they can sell sand with a value of over 100,000 yuan (US$12,900) in one night.
Dr Wang Kexiong, head of the survey team, told me that on a normal day there are countless thousand-tonne dredgers and transport ships on the lake. The dredgers are arranged in a line in the centre of the lake. With the tall cranes and other machinery on the ships towering over each other, the scene resembles a bustling urban construction site.
Workers on the Dredging King say that they often see porpoises leaping out of the water near the ship. But they know nothing of the porpoise’s status as a designated national endangered species, or about how dredging has affected porpoise populations.
Poyang Lake’s finless porpoises make up a quarter of the country's total population of the animal, which are mostly otherwise confined to small streams. One internationally-renowned scientist studying whales and dolphins has called their demise “a massive ecological disaster.”
In the lake’s muddy waters, the porpoises cannot see as far as they once could, and have to rely on their highly-developed sonar systems to avoid obstacles and look for food. “One large ship passes through the mouth of Poyang Lake every 30 seconds,” said Wang Kexiong. “With such a high density of shipping, the porpoises cannot swim freely from one bank to another. They don't even have a chance to come up for air or hunt for food.” Moreover, with the massive amount of noise from ships transporting sand interfering with their sonar systems, it is even harder for the porpoises to locate fish to eat.
Zhou Junqi, director of fisheries for the area around the lake’s mouth, in Jiangxi province, said that the sand dredging first began in Poyang Lake after large-scale flooding in 1998. In the first few years, there was no obvious effect on the fishing industry or the environment. The dredging brought in a lot of money very quickly, and allowing it to continue was much easier than trying to think of other ways of attracting investment to the area.
The last few years have seen an increasing number of ships weighing over 1,000 tonnes, said Zhou. Aquatic plants and animals that used to swim in the lake have disappeared. The migration routes of semi-migratory fish have been disrupted by ships dredging and transporting sand. The breeding grounds for fish that once laid their eggs in sand and among rocks and plants have been destroyed. As a result, fish and shrimp populations have been falling every year, cutting off the food supply to porpoises, which now have trouble growing to their full size.
Sand dredging brings in tens of millions of yuan to the Poyang Lake region every year, a considerable sum for counties that are lagging behind in economic development. But academics are now asking: who is going to pick up the bill for the damage done to the local environment and resources?
Making room for the porpoise
Shipping and sand dredging on the lake continue to create a cacophony that has had a disastrous effect on the porpoise population. Now we must prohibit indiscriminate dredging, regulate and manage the industry.
In recent years, the Institute of Hydrobiology has caught finless porpoises from more biodiverse sections of river, in Ezhou, Tongling and Zhenjiang, and transferred them to the Tian'ezhou Reserve to create a larger breeding group of porpoises – which is more balanced in terms of age and gender. They have also attempted to link up some previous tributaries and wetlands of the Yangtze River that had been cut off due to land reclamation or other projects. This will expand the area of the reserve and give the porpoises a chance to meet other members of their own species.
However, at the same time as steps are being taken to protect the porpoises, back on Poyang Lake where the population is mostly concentrated, the large numbers of ships and the noise they create are seriously affecting the lives of porpoises. Dr Li Songhai, who has studied the porpoises' sonar system, explained that this system of echo-location is very highly developed. If the porpoises pick up unusual disturbances in the water, it can lead to abnormal behaviour. This is often what causes whales to beach and die.
In March 2000, within two days of the US Navy conducting antisubmarine exercises using sonar buoys off the Bahamas, 14 whales were found beached, eight of which later died. Scientists that analysed the bodies of the whales believe that the US naval exercises had a direct influence on the beachings.
Experts believe that the porpoises will only be safe if ships do not exceed a speed of five kilometres per hour and maintain a distance between ships of at least one kilometre. Dr Li reserves particular loathing for the speedboats that dart about on the lake. “Not only are they very noisy, but also the porpoises have no time at all to get out of the way, meaning injuries can be caused at any moment,” he said.
The main trunk of the Yangtze River used to be the ideal habitat for porpoises, but with the expansion of human economic activity, they have been squeezed into Poyang Lake and Dongting Lake, where they are only just surviving. Scientists from the Institute of Hydrobiology are deeply troubled by the question of whether or not these rare, ancient “natives” of the Yangtze River can continue to survive.
The increase in GDP around Poyang Lake, brought about by sand dredging, comes at the cost of sacrificing the natural environment and its biodiversity. Most local officials, in their push for GDP, have neglected environmental protection and forgotten the baiji and the finless porpoise.
Conservation experts emphasise that once a species is extinct, it is gone forever. If we want stop the finless porpoise from going the same way as the baiji, the most important thing is to understand exactly why we want to save the creature. In particular, government officials need to genuinely understand the meaning of sustainable development. We need to instil in them the awareness of the need for environmental protection.
Benefits of tourism
If a tourism industry based around porpoise-watching tours can be developed, and the fishing industry can be stopped, then perhaps the habitat of this highly endangered animal can be rebuilt. A porpoise-watching industry could massively stimulate awareness of the need to protect oceans, lakes and rivers, believes Wang Kexiong. Tourism could be a form of economic development in itself, providing high incomes that could replace any losses.
As the porpoises are migratory, it is still possible that in different seasons they could appear in other areas – despite the terrible state of the Yangtze mostly confining them to Poyang Lake and the Tian'ezhou Reserve.
But Wang Kexiong says that scientists still only know a tiny amount about the porpoises, their breeding habits and behaviour. Therefore, it’s hard to say when such a porpoise-based tourist industry could start to be developed.
Faced with an ominous decline in porpoise numbers, Wang Ding and other experts call for the establishment of a network to observe, protect and save the “river pigs”, using existing reserve areas and fisheries management systems. They want long-term observation of key stretches of river in order to prepare for the creation of a semi-wild breeding group of porpoises. They also want all national and regional baiji reserves to be renamed Yangtze River dolphin and porpoise reserves.
In addition to this, they are urging that the finless porpoise should be immediately recognised as a grade one protected species, with the related legal measures quickly implemented. They are calling for Poyang and Dongting lakes become safe havens for porpoises, and as such to be more strictly monitored and protected. A Yangtze River Protection Act should also be drawn up, say the experts. This should limit and phase out fishing activities, regulate the development of the shipping industry and prohibit or tightly control sand dredging in the Yangtze River and lake regions.
Kejia Zhang is a senior reporter and editor with China Youth Daily