IUCN/SSC Otter Specialist Group Bulletin

© IUCN/SCC Otter Specialist Group

Volume 28 B: Proceedings XIth International Otter Colloquium, 30 August -4 September 2011, Pavia, Italy

Abstracts

Ecotoxicology of the Eurasian Otter (Lutra lutra) along Loire River (France) and Predictable Trends due to Global Change
Pages 5 - 14
Charles Lemarchand, Rene Rosoux and Philippe Berny
In this study, about fifty otters from the basin of the Loire River (France) were analyzed in the context of a toxicological study funded by the Plan Loire Grandeur Nature. Individuals were recovered non-invasively, using a network of collection of otters killed by traffic collisions with vehicles. The chemical elements analyzed were the organochlorine and organophosphorus pesticides, carbamates, pyrethroids, herbicides, anticoagulants, PCBs and metals. Detectable levels of organochlorine pesticides and PCBs characterized all otters analyzed, with mean values reaching 2-15 mg kg-1, respectively. Concentrations of other analyzed pesticides remained very low. For metals, contamination of otters was systematic for lead and mercury, the latter being relatively abundant in tissues of several individuals. A significant trend to increasing concentrations of pesticides and PCBs by going towards the downstream parts of basins was shown. The inter-individual variations in concentrations were marked. Global values of contamination were below the toxicological threshold defined for the conservation of the species, and the current dynamics of populations within the basin of the Loire seems to confirm this. However, the potential effects of mixtures of compounds remain poorly studied.
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How To Calculate Range And Population Size For The Otter? The Irish Approach As A Case Study
Pages 15 - 22
Ferdia Marnell, Lughaidh Ó Néill and Dierdre Lynn
All EU Member States are obliged to submit reports to the EU Commission every 6 years, detailing the conservation status of species and habitats listed on the Habitats Directive. The otter (Lutra lutra) is one such species. Despite a number of national surveys that showed that the otter was widespread across the country, in Ireland’s 2007 conservation status assessment the otter was considered to be in unfavourable condition. While the Range, Habitat and Future Prospects categories were all considered favourable, Population was deemed to be unfavourable.
This paper examines the data behind the 2007 assessment by Ireland, which included three national otter surveys and a series of radio-tracking studies. Range was mapped and calculated based on the results of national distribution surveys together with records submitted from the public. Population size was estimated by calculating the extent of available habitats (rivers, lakes and coasts), dividing that by the typical home range size and then multiplying the result by the proportion of positive sites in the most recent national survey.
While the Range of the otter in Ireland did not decrease between the 1980/81 and the 2004/05 surveys, Population trend was calculated as -23.7%.  As a consequence, the most recent national Red Data List for Ireland lists the species as Near Threatened (Marnell et al., 2009).
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Otters Caught in Traps: A Minor Problem or the Tip of an Iceberg?
Pages 23 - 25
Mia Bisther
In Sweden, only four otters have been reported killed in mink traps during the last three decades. But one third of 1 024 traps found during otter surveys 1989-2010 were illegally constructed. The most frequent incorrectness was a too large entrance hole of the trap. This considerable increases the risk for otters to get caught in traps. There is a need for changed regulations as well as better information about trap selectivity.
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Natural Recolonization of the Eurasian Otter (Lutra lutra) in Massif Central (France)
Pages 26 - 29
Christian Bouchardy, Charles Lemarchand, Yves Boulade, Noël Gouilloux, René Rosoux and Philippe Berny
The natural expansion of otter populations from thier stronghold in the Massif Central was followed over four decades, with regular monitoring. In this area, many of the watersheds between drainage basins are themselves wetlands, and otters were able to overcome many natural barriers such as dams, by crossing these watersheds. This, along with conservation of riparian corridors, has facilitated otter recovery. The connections between wetlands and watersheds is as important as the linear routes along watercourses
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Trends in Otter-Related Newspaper Articles in Japan over 135 Years
Pages 31 - 35
Kayoko Yamamoto and Motokazu Ando
To understand the chronological change in people’s interests and attitudes toward the Japanese otter, which became extinct during the 1990s, the number and contents of otter-related newspaper articles over 135 years were investigated. This investigation shows that, in the consciousness of people, the otter shifted gradually from being the animal of a neighborhood in the 19th century, economic value in the early 20th, conservation need in the late 20th, and symbolic value after 2000. Presently, the number of otter articles is progressively decreasing owing to a lack of news.
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Rescue, Tagging and Release of a Neotropical Otter (Lontra longicaudis) in Western Brazilian Amazon
Pages 36 - 46
Miriam Marmontel, Cristina Isis Buck Silva, Robinson Botero-Arias and Hadad A. Miguel
We report the rescue of a young Neotropical otter in western Brazilian Amazon and the process of quarantine, rehabilitation and preparation for release, including infectious disease tests. Prior to release a VHF transmitter was implanted in the intraperitoneal cavity of the animal. The otter was released in a sustainable development reserve in the vicinity of capture site, and had its movements followed for a short period. This is the first case of tagging and release of a Neotropical otter in the Amazon.
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Ramsar Protected Wetlands of International Importance as Habitats for Otters
Pages 47 - 63
Robert P. Brooks, Thomas L. Serfass, Maggie Triska and Lisa-Maria Rebelo
Wetlands of International Importance, as listed by the Ramsar Convention, can provide valuable opportunities to conserve otter species worldwide. Adopted in 1971, the Convention originally focused on protecting habitats for waterfowl. Since then the convention has broadened its scope to cover all aspects of wetland conservation and wise use, recognizing wetlands as ecosystems that are extremely important for biodiversity and for the well-being of human communities. By the end of 2011, there were 1,971 wetland sites designated globally covering over 191 million ha. As an intergovernmental treaty the Ramsar Convention provides the framework for national action and international cooperation for the conservation and wise use of wetlands. Under Ramsar, wetlands are broadly defined, encompassing the wide range of habitats on which all 13 species of otters depend. Lakes, rivers, swamps, marshes, mangroves, and estuaries are included as listed sites. Many sites consist of a mixture of wetland types, and some include significant human activities, such as fishing, agriculture, and ecotourism. Of obvious interest is IUCN’s commitment to conserving biodiversity, through efforts such as maintaining the Red List of Threatened Species, where selected otter species are listed. Here, we show with maps the number of Ramsar sites located within the range distributions of each otter species. Yet, more can be done to promote awareness of otters’ reliance on wetland habitats with high ecological integrity. A stronger alliance between IUCN’s Otter Specialist Group and the Ramsar Convention should be forged to enhance existing efforts to conserve this flagship species and its habitats.
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Local Knowledge and Conflicts With Otters in Western Brazilian Amazon: A Preliminary Report
Pages 64 - 68
Vania Fonseca and Miriam Marmontel
Traditional knowledge constitutes an alternative source of information on animal biology and ecology. This is especially important when research projects are undertaken in collaboration with local populations living in the area of interest. In this study we aimed to characterize and summarize ethnobiological information on two species: the Neotropical otter (Lontra longicaudis,) and the Giant otter (Pteronura brasiliensis), and assess their possible interactions with fishing activities in the Amanã Sustainable Development Reserve, Western Brazilian Amazon. Five traditional communities were visited each month since December 2010 during an ongoing investigation of otter-fisheries conflicts. Anecdotal information obtained is presented concerning otter classification, behavior, and interaction of otters with fishing.
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Preliminary Findings from a New Study of the Congo Clawless Otter (Aonyx congicus) on the Dji Dji River, Ivindo National Park, Gabon (or “Where Have all the Otters Gone?”)
Pages 69 - 84
Lisa C. Davenport, Hélène Jacques and Marie-Louise Yedi
The Congo Clawless Otter (Aonyx congicus), is a little-known otter species that inhabits central African rivers and swamps. We report on the results of 3 field expeditions into the Dji Dji River, (Ivindo National Park, Gabon) of varying length (3 days to 6 weeks) to collect preliminary observations on this species, the sympatric spot-necked otter (Lutra maculicollis), and the fish community of the Dji Dji River. We also surveyed local people (primarily artisanal fishermen) in the Makokou area of Ivindo National Park about their knowledge of otter species and human/wildlife conflicts in the area. Sightings of otters in 2010 indicated both otter species to be common on the Dji Dji River. Fish sampling in 2011 indicated high abundance but low diversity of fishes in this blackwater river. Feeding observations of a solitary animal on the Dji Dji and a family of 3 on the Ivindo River indicate a high dependence on large earthworms (Annelidae) captured near the river’s edge. With a severe drought in 2011 affecting the Dji Dji River level, we found fewer otters compared to 2010 observations and no families with young. We speculate on the possibility of seasonal downstream movements, which could affect conservation of the species in the region.
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Recovery of the Eurasian Otter Lutra lutra in Korea and the Change in Public Attitude
Pages 85 - 90
Hyeonjin Kim, Motokazu Ando, Sungyong Han, Hiroshi Sasaki and Hiroshi Ogawa
Since the 1970s, South Korea has attained unparalleled and rapid economic growth. To analyze the impact of subsequent habitat deterioration on the Eurasian otter (Lutra lutra), the distribution of otter spraints along sea coasts and major rivers was surveyed in 1982, 1991–94, and 2010. On the basis of the density of spraints and questionnaire-based surveys given to local residents, scores ranging from 0 (no information and no spraints) to 3 (>1 spraint/500 m) were assigned to each study area. Along rivers, the average scores decreased from 1982 to 1991–94, but recovered in 2010. In coastal areas, the scores were rather constant from 1982 to 2010. During 1971–2010, the number of otter-related articles increased almost in proportion to the rise in the GDP. During this period, the content of otter-related articles shifted from its use as a fur animal to that of an animal symbolic of healthy environments.
Contents | Full Text + Links | PDF (338 KB)

The French Action Plan For The Eurasian Otter
Pages 91 - 100
Rachel Kuhn and Hélène Jacques
A National Action Plan for the Eurasian otter was prepared in 2009 by the French Mammal Society (SFEPM) and is implemented from 2010 until 2015. This project is part of the action plan policy of the French Ministry of Ecology. The first part of the plan is a status report on otter in France and the second part presents the conservation strategy for the next five years. The main issues of the plan are the strengthening of the stakeholder network and the development of cooperation to improve research and conservation, a better circulation of knowledge about otter biology and conservation issues, the implementation of actions to reduce otter mortality, protect and restore otter habitat and increase prey availability and the improvement of cohabitation between otter and aquaculture.
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