Threats and opportunities for the survival of the Yangtze finless porpoise

Abstract: The Yangtze finless porpoise (Neophocaena phocaenoides asiaorientalis), is a small freshwater cetacean which has recently fallen dramatically in number. It is an endemic species for the Yangtze River and unless drastic action is taken, it risks the same fate as the now functionally extinct Yangtze river dolphin (Lipotes vexillifer). Threats to the porpoise are diverse but they have in common that they are caused by man. Development of the river has been made to supply a growing human population with food, hydropower, and to reduce the risk of flooding. These changes have resulted in a degraded habitat for the porpoise. A major problem is that the species natural behaviour and morphological adaptions to a life in a river exposes it to serious risks. Porpoises navigate by echolocalization and have poorly developed eyes due to the turbid water in the river. Today this navigation is made difficult by the heavy vessels trafficing the Yangtze River. It is common that porpoises collide with vessels which lead to injuries and even death. Another behaviour that causes problems is that the porpoise hunt near the river bottom. This is the area where fishermen lay down most of their fishing gear. This increases the risk that they will get entangled which ultimately leads to their death. Measures have been taken to try to save the species. Conservation work is conducted in captivity, ex situ and in situ. Ex situ work takes place largely in the restored oxbow lake Tian’e-Zhou where porpoises breed naturally in an environment with reduced fishing and vessel traffic. The in-situ work is performed in established reserves in the main river. In captivity, the porpoises reproduce successfully and behavioural research can be conducted on them. However, it is important to work towards a restoration of a decent living environment in the Yangtze River since in-situ conservation should be the goal of all conservation work. The Yangtze River is such an important resource for the local people, and the species living in and around it that a big effort should be applied to preserve it. It seems that the re-creation of oxbow lakes has favored the species and establishment of more of these semi-natural reserves would therefore be of further benefit. Even so, this alone will not suffice to ensure the porpoise future. In order to give the species a fair chance of survival, efforts from many directions is required. Industry, government, local people and not least consumers across the world must pull together to restore the Yangtze River, thus giving the Yangtze finless porpoise a chance to survive.