Milestone in race to save Yangtze finless porpoise
And the hope is that this new population will help the finless porpoise avoid the fate of the Baiji dolphin, which shared the waters of the Yangtze River until it became functionally extinct in 2006.
Under a plan developed by the Ministry of Agriculture (MOA), four finless porpoises were moved from Poyang Lake to holding pens on March 21st and will be released into their secure new habitat in the He-wang-miao /Ji-cheng-yuan oxbow on March 27th. Four others will be translocated to the Tian-e-zhou oxbow to boost the genetic diversity of its existing population.
The eight finless porpoises – part of an estimated population of just over 1000 – were captured earlier this month using the safe, scientifically approved ‘acoustic drive netted method’.
“Without urgent efforts such as this translocation, the Yangtze finless porpoise could be extinct in the next 5-10 years and the world would lose another of its unique and irreplaceable freshwater cetaceans,” said Lo Sze Ping, WWF China CEO. “WWF has been working with the government and partners for years to protect and enlarge finless porpoise habitats along the Yangtze, and we welcome the creation of this new population.”
A thriving new population is critical to the species’ survival because its numbers are still declining at around 13.7% per year due to the environmental impact of human activities along the Yangtze, including shipping, sand mining, pollution, illegal fishing and water projects. Dead porpoises are regularly found along the main stream of the Yangtze as well as in Dongting and Poyang lakes.
And the omens are good since an earlier translocation has proven successful.
In the 1990s, under the leadership of the MOA, the Institute of Hydrobiology of the Chinese Academy of Science (CAS) and other institutes established a reserve in the Tian-e-zhou oxbow and successfully translocated finless porpoises from the main Yangtze river.
Over the next 20 years, while finless porpoise numbers plummeted in the main river, the population in the Tian-e-zhou oxbow slowly increased. Indeed, the oxbow is now approaching its carrying capacity, which is another reason why the new porpoise expansion site is so vital and timely.
“The environment of the Yangtze River is not going to be problem-free overnight, so to ensure the finless porpoise survives, we need to look for the best places for this ancient animal to live, where there are fewer harmful human activities for them to cope with,” said Professor Ding Wang, head of the Research Group on Conservation Biology of Aquatic Animals of the Institute of Hydrobiology of CAS.
The He-wang-miao/Ji-cheng-yuan oxbow was chosen after rigorous scientific study and debate. Formed in 1968 after the Yangtze river was diverted, the oxbow is a large body of water that used to shelter not only finless porpoises but also Baiji dolphins, Chinese sturgeons and Chinese paddlefish. Seasonally connected to the Yangtze, the oxbow is still home to 34 fish species and boasts good quality water and the right environmental conditions for the porpoises.
“China has shown that finless porpoises can thrive when relocated to more secure areas away from the main Yangtze river,” said Aimée Leslie, Global Cetacean and Marine Turtle Manager. “The new site has been chosen because it offers the best available conditions for the founder population to survive and thrive.”
The oxbow has been divided into three distinct areas – core, buffer and experiment. All fishing activities have been prohibited in the core area, which boasts the most suitable habit for the porpoise and is separated from the buffer zone by protective nets. The porpoises will be released into this core area, where they will have 16.6 km2 of safe water to enjoy.
While some fishing activities will be allowed in the buffer and experiment zones, WWF has been working with local authorities to draw up a plan to provide technical and financial support over the next 3-5 years to help local fishermen develop alternative livelihoods.
“The survival of this new population of Yangtze finless porpoises depends on the support and involvement of the local communities,” said Lei Gang, WWF Yangtze programme senior director. “By helping fishermen to develop new ways of providing for their families, WWF and the local authorities are ensuring that the translocation will benefit both porpoises and people.”
This week’s translocation is the first step in a long process. Later this year, four porpoises will be moved from the Tian-e-zhou oxbow to the He-wang-miao/Ji-cheng-yuan oxbow – with another four making the same trip towards the end of 2017.
If all goes well, the He-wang-miao/Ji-cheng-yuan oxbow could eventually be home to 100 Yangtze finless porpoises. Together with the Tian-e-zhou oxbow, the new site will form part of a network of finless porpoise reserves that will not only protect viable populations but also allow individuals to be exchanged between them to maintain the species’ overall genetic diversity.
And that will give this extraordinary species the best chance of survival – and of not joining the Baiji dolphin in disappearing from the waters of the Yangtze forever.