Asian Small-Clawed Otter Husbandry Manual (1998)

Action Plan for Asian OttersPat Foster-Turley and Charles SantiapillaiIntroductionFive species of otter are known from Asia. They are Eurasian otter (Lutra lutra); smooth otter (Lutraperspicillata); hairy-nosed otter (Lutra sunwtrana); Asian small-clawed otter (Aonyx cinerea) andthe sea otter (Enhydra lutris).Throughout their distribution in Asia, otters are being threatened by a combination of habitat destruction,hunting, and environmental pollution, especially from the organochlorines. The demand for naturalresources in the Asian region is bound to increase sharply. The human population is predicted to reach3.4 billion by the year 2000 and is not expected to stabilize below 6 billion in the latter part of thetwenty-first century. This growth rate alone indicates a doubling in the demand on the natural resourcesevery 30 years or less. In reality, the situation is likely to be worse than this, since most Asianeconomies are booming, and the resource use per person can be expected to increase drastically overthe next 20 years. One of the consequences of the burgeoning human population across Asia is therapid conversion of forests to other land uses. The conversion of forests in general and the riparianvegetation in particular is a serious conservation problem in Asia. Otters are among the animals thatsuffer.Direct threats to the otters in Asia include killing them for their pelts, or for their organs, which arethought to have medicinal value in some regions. Otters are also sometimes killed because they arethought to compete with fishermen, or because of their depredations upon fish-farming operations. Theindirect threats such as pollution of the environment with industrial and agricultural wastes are even moreserious. Of particular concern are the organochlorines, especially PCBs (polychlorinated biphenyls),which are bio-magnified at the top of the food chain. As the level of PCBs in the wetlands increases,there is usually a general decline in aquatic mammals, such as otters. It is therefore quite alarming tonote that large quantities of PCBs are still in use in Asian countries. Unless these are collected anddestroyed, they will remain a potent threat to the survival of the otters and other wildlife in the wetlands.Evidence suggests that the accumulation of PCBs has been largely responsible for the widespreaddecline of populations of the Eurasian otter in Western Europe (Mason and Macdonald 1986a). Asimilar problem could be developing in Asia. In many countries in Asia where otters were oncecommon, they have disappeared due to a combination of the direct and indirect threats. In Hong Kong,Japan, and Singapore, otters are believed to be extirpated, and otters of all species are rare in much ofthe rest of Asia.Despite the overall pessimistic condition facing otters in Asia, there are some causes for guardedoptimism as well. In Peninsular Malaysia, for instance, otters are still widespread in many areas, evenbeyond the boundaries of protected areas. In other countries, healthy populations of otters remain inAsian Small-Clawed Otter Husbandry Manual/Action Plan64