For a detailed account of the environmental impacts of Euglandina rosea please read: Euglandina rosea (Rosy Wolfsnail) Management Information. The information in this document is summarised below.
The future for some of French Polynesia’s partulids may not be as bleak as once thought; according to recent studies relatively high genetic diversity is represented among living taxa and it may still be possible to preserve a representative sub-sampling of Raiatea and Tahiti’s tree snail diversity (Lee et al. 2009; Ó Foighil 2009).
Physical Control: The ultimate objective of captive breeding programs is the reintroduction of viable populations of endangered species into their natural habitats (Coote et al. 2004). Small exclosures have been built in Hawai‘I and on Moorea (French Polynesia) to protect native tree snails from attack by Euglandina rosea.
Legislation: It is almost impossible to prevent the within-island spread of Euglandina in French Polynesia (Coote et al. 1999). Between-island spread of Euglandina should be prevented by legislation. The Marqueses Islands, the Southern Cooks and the Australs provide refuges for some of the remaining partulid species (Lee et al. 2007a) and should be kept Euglandina-free. E. rosea is now legally considered to be a noxious species in French Polynesia; the introduction of live specimens and their transport from one island to another is forbidden (Meyer 1998).
Other: Since 1986 partulid snails have been the subject of an international breeding programme; the International Partula Conservation Programme manages a breeding programme for 25 species in 15 zoos worldwide. Introducing Society Island partulids to the Austral Islands that are free of the predator might ensure their long-term survival in the wild (Ó Foighil 2009). Coote & Loeve (2003) concluded that E. rosea was extinct in the wild on Huahine, strongly suggesting that the successful re-introduction of partulids into the wild on Huahine might be possible.
Conservation actions in the wild may be limited to identifying and protecting populations of partulid snails that offer some possibility of persistence in the presence of Euglandina (Ó Foighil 2009). Based on laboratory behavioral studies of the effect of temperature on E. rosea movement, Gerlach (1994, in Ó Foighil 2009) hypothesised that an altitudinal refuge above 600 to 700 m would exist for Society Island partulids.
Research and Knowledge: Further research into the biology of E. rosea, and particularly its population dynamics, needs to be carried out. There are no known natural predators, so a species-specific toxin in snail bait, as tested in Hawaii (M. G. Hadfield pers. comm., in Coote et al, 1999), could be a promising approach. A good relationship between the Pacific Island Land Snail Group (PILSG) and the French Polynesian government authorities has developed, and joint initiatives for conservation and research are being planned (Coote et al. 1999).
Education and Knowledge: Despite the lack of evidence supporting Euglandina as a successful biological control agent and despite the abundant evidence of their negative predatory impact on native snail fauna, carnivorous snail introductions continue (Cowrie 1992). Clearly public education about the French Polynesia’s precious natural fauna and the dangers posed to such fauna by carnivorous biological control agents could help to reduce the likelihood of Euglandina being purposefully translocated to new islands. Local willingness and experience are already in place to conserve French Polynesia’s partulid snails (Coote & Loeve 2003).
Location Specific Management Information
Bora Bora (Pora-Pora) Is. (Society Islands)
The only native snail on Bora Bora of the Partula genus probably became extinct soon after 1986, the year that Euglandina rosea was introduced. The most recent survey was in 1991.
Huahine Is. (Society Islands)
All three native snail species of the Partula genus on Huahine were extinct in the wild by 1997, but 2 species survive in captivity. The most recent survey was in 2000.
Moorea Is. (Society Islands)
It was believed that all seven native snail species of the Partula genus on Moorea were extinct by 1987. However, a small population of one species was located in 2001 by Jean-Yves Meyer of the French Polynesian Research Department. Five species survive in captivity. Attempts are being made through the International Union for the Conservation of Nature (IUCN) for the captive breeding of those stocks that remain in the laboratory (Murray et al 1988)
Raiatea Is. (Society Islands)
The unexpected discovery of these two surviving montane populations raises the possibility of preserving some fraction of Raiatea’s endemic tree snail diversity in the wild (Lee et al. 2008).
Partulidae are clearly a highly threatened family of invertebrates and in need of the most intense conservation focus.
1. Carlton, J.T. & G.M. Ruiz. 2003. Invasive species: vectors and management strategies. Island Press.
2. Civeyrel, L. and Simberloff, D. 1996. A tale of two snails: is the cure worse than the disease? Biodiversity and Conservation 5: 1231-1252.
Summary: A discussion of the introduction of predatory snails (notably Euglandina rosea), in putative attempts to control A. fulica. The devastating consequences on native land snail diversity, especially in the islands of the Pacific.
3. Clifford, K.T., L. Gross, K. Johnson, K.J. Martin, N. Shaheen & M.A. Harrington. 2003. Slime-Trail Tracking in the Predatory Snail, Euglandina rosea, Behavioral Neuroscience 117(5): 1086-1095.
4. Coote, T., D. Clarke, C.S. Hickman, J. Murray & P. Pearce-Kelly. 2004. Experimental Release of Endemic Partula Species, Extinct in the Wild, into a Protected Area of Natural Habitat on Moorea, Pacific Science 58(3): 429-434.
6. Gargominy, O. 2008. Beyond the alien invasion: a recently discovered radiation of Nesopupinae (Gastropods: Pulmonata: Vertiginidae) from the summits of Tahiti (Society Islands, French Polynesia), Journal of Conchology 39(5).
7. Hadfield, M. G., Miller, S. E. and Carwile, A. H. 1993. The decimation of endemic Hawai‘ian tree snails by alien predators. American Zoologist 33: 610-622.
Summary: Discusses the impacts of alien rats and Euglandina rosea on native Hawaiian tree snails.
8. IUCN/SSC Invasive Species Specialist Group (ISSG)., 2010. A Compilation of Information Sources for Conservation Managers.
Summary: This compilation of information sources can be sorted on keywords for example: Baits & Lures, Non Target Species, Eradication, Monitoring, Risk Assessment, Weeds, Herbicides etc. This compilation is at present in Excel format, this will be web-enabled as a searchable database shortly. This version of the database has been developed by the IUCN SSC ISSG as part of an Overseas Territories Environmental Programme funded project XOT603 in partnership with the Cayman Islands Government - Department of Environment. The compilation is a work under progress, the ISSG will manage, maintain and enhance the database with current and newly published information, reports, journal articles etc.
9. Mead, A. R. 1961. The giant African snail: a problem in economic malacology. Chicago, University of Chicago Press.
Summary: Major treatise on the worldwide spread of A. fulica, its impacts, and management.
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