Otter populations and their distribution in China – A review

Zhang Xaohong1, Paul Yoxon2, Grace M Yoxon3

1 Wetlands International-China, Room 501, Grand Forest Hotel, No. 3A, Bei Sanhuan, Zhonglu Road, Beijing, P.R. China 100029. Email: zxh@wetwonder.org

2 International Otter Survival Fund, 7 Black Park, Broadford, Isle of Skye IV49 9AQ, Scotland. Email: Paul@otter.org

3 International Otter Survival Fund, 7 Black Park, Broadford, Isle of Skye IV49 9AQ, Scotland. Email: Grace@otter.org

Abstract
There are three species of otter in China: Eurasian otter (Lutra lutra), Smooth-coated otter (Lutra perspicillata) and Asian small-clawed otter (Aonyx cinerea). This paper presents a literature review of the status of otters in China both a historic and current context.

Introduction
Otters are a top predator in wetland ecosystems as they use both the land and aquatic habitats and they therefore serve as an indicator species as to the health of the environment.

There are five species of otters in Asia, and three can be found in China: Eurasian otter (Lutra lutra), Smooth-coated otter (Lutra perspicillata) and Asian small-clawed otter (Aonyx cinerea). The Eurasian otter, as its name suggests, is widely distributed in Asia and Europe (Qing et al. 1996). Five sub-species are identified (L. l. lutra, L. l. chinensis, L. l. hainana, L. l. kutab and L.l nair). The Asian small-clawed otter is mainly found in the south and southwest of China. The smooth-coated otter is only distributed in Guangdong and Yunnan (Ma, et al., 1999).

The Conservation Status as identified by the IUCN Red List of Threatened Species of the species is as follows: Eurasian otter – Near Threatened, Smooth-coated otter and Asian short-clawed otter – Vulnerable (Schipper, J et al. 2008)

Otters used to be widespread in China except for in a few provinces in arid zones but now they are hardly ever observed in the wild and spraints or footprints can be occasionally observed in only a few provinces near streams, reservoirs or protected areas.

Otter distribution in China
Based on the China National Wetlands Survey completed in 2003, otters could only be detected in 12 provinces and 3 autonomous regions, and they are rare in 9 of the 15 provinces and regions. It is possible that the Eurasian otter is present in the west of Hainan and Mai Po Inner Deep Bay, Hong Kong, where it is strictly protected (Suen 2003, Shek 2006). During the National Wetland Survey, the smooth-coated otter was solely found in Dongguan City, Guangdong Province. In South China the smooth-coated otter was recorded only on the western bank of the Pearl River Estuary (including nearby Taishan), and in coastal Guangdong (Xu et al. 1987, Liu 1992, Zhang 1997, Wozencraft 2008); There are no recent records of this species from China (Smith et al., 2009). The Asian small-clawed otter was found in the narrow niche of Sichuan, Hainan, northern Guangxi and northern Guangdong. Generally the population of otters in China has declined drastically or is extinct.

The literature reviews indicated that otter populations are greatly reduced and they are seldom observed in their natural habitats. A brief summary is given here of published papers or reports relating to otters in China (See Fig 1).

Figure 1. Map showing locations of otter records

Otters occurred in the Bailongjiang and Baishuijiang rivers (upper streams of the Yangtze River),southern Gansu Province. Hunting was stopped by the provincial government in 1958 as the otter population had been so dramatically reduced (Song, et al., 1960). During the mid-1940s, 200-300 skins were collected each year but a total of 54 skins were collected between 1972-1981 (Xiao, 1985). In terms of survey data from Jiangsu, Hunan and Hubei provinces, otters accounted for 6.76% of the yields in the 1950s. (Sheng, et. al., 1987). In 1990 wildlife lists were released that showed the otter listed as an endangered species in Taiwan. Field surveys proved that the otter was rarely observed in 1984, 1987, 1990 and 1992 in Xingkai (Khanka) Lake, bordering with Russia (Li, et al., 1993). Based on the survey in 1997-1998 it was estimated that some 20 otters remained in Neilinding Island, Guangdong (Wang, 1999). Less than 10 otters were observed in the stream near the reservoir of Zhejiang Province (Lu, et al., 2001). Field surveys between 1999-2000 in Shanxi Province and interviews with hunters, medical herbs collectors, and rangers showed that otters were present in Lishan Nature Reserve but numbers are very low (Jia, et al., 2002). Xingjiang Daily (2004) released the news that otters had become extinct in Xinjiang Uygur region. Otters were observed in Qiyunshan provincial nature reserve, Jiangxi, but are rare. In a survey of the reserve 45 mammal species were recorded but otters made up only 2.2% of these records (Yang et al.,2009).

The Vertebrates Survey (2001-2003) found that some rare species including otters had disappeared near Lhalu wetland, Tibet compared with 1970s-80s (Pu, et al., 2010). The latest and most complete field inventory on the otter and its food chain was researched in Changbaishan Mountain. This is one of the national nature reserves in the northeast of China, where the Changbaishan Scientific Research Institute has carried out a long term monitoring of otters from 1980 to 2010 (Piao, et al., 2011). The results showed that the otter population began to decrease in 1990. By 2010, the population had been reduced by 99% compared with 1975. The historical data indicated that 1,360,000 otters used to inhabit the nature reserve in 1975, 33 otters remained in 1985, 5-15 in 1990-2000 and 0-4 was estimated in 2001-2009. This information is based on surveys.

Habitat fragmentation, especially the degradation of wetlands, has had a significant impact on otter populations but over-hunting, especially for the illegal fur trade, threatened their survival in many parts of China. Other threats include shortage of food sources, hydrological engineering and water pollution (Ma.et al., 1999; Sheng, et al., 1987; Xu, 1984; Lu, 2001; Pu 2010; Piao 2011; Zhang, 2008; Li, 2000; Lau 2010).

Otters were excessively harvested by trapping in the 1950s-70s as their fur demanded a high price in the market. Over 10,000 furs were collected in the 1950s, 864 pieces in 1966, but only 382 in 1981 (Ge,1983, Xu, 1984). In 1957, It was reported that over 4,900 pelts were purchased in Guangxi but the annual yield had dropped to 36 pelts by 1979 (Wu 1993, Lau, 2010)

Based on the report by the International Otter Survival Fund (IOSF) however, the fur trade is still prevailing in some remote areas, even though in China it is illegal to hunt otters as they are listed as Category II of National Protected Animals by law since 1995. Some transboundary illegal trade or smuggling among the borders of China, Nepal, Burma and India still exists as in Tibet where otter furs are used to trim part of their dress – the chupa. Otter body parts such as liver, bones and tail have been used in traditional Chinese medicine, but there is little information on current use and also there are insufficient products available.
Conclusions
There remain some knowledge gaps in the status of otter populations and natural habitats throughout China as there has been no comprehensive, scientific survey of this species over the five decades. Extensive fieldwork would provide valuable up to date information to identify the species and prioritise sites for conservation actions. Ecological information relevant to conservation, such as habitat use and intervention patterns, could also be investigated during such research.

Therefore it is very urgent to conduct a national survey of otter populations in potential provinces. Better research and strict enforcement within protected areas will be supported if the remaining mammalian fauna is to be preserved and revived. A concerted and sustained public education effort will be required to reduce the drivers of the wildlife trade. Transboundary cooperation in wildlife conservation will be strengthened among neighbouring countries to control and fight against illegal hunting and fur trade.

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