Background information and definitions
Amphibians are traded for a number of reasons including consumption, the pet trade, for zoo animals and scientific purposes. For example, it was estimated that 15 million live, wild-caught amphibians entered the USA legally in 1998–2002, millions of which were for the pet trade (Schlaepfer et al. 2005). Removal of large numbers of amphibians from the wild can have significant effects on populations.
The movement of animals also increases the risk of spreading infectious diseases. For example, there is increasing evidence that trade is partly responsible for the recent spread of chytridiomycosis Batrachochytrium dendrobatidis and amphibian ranaviruses (e.g. Daszak et al. 2003; Gratwicke et al. 2009; Schloegel et al. 2009).
Evidence for interventions designed to reduce the threat from diseases is discussed in ‘Threat: Invasive alien and other problematic species – Reduce parasitism and disease’.
Daszak P., Cunningham A.A. & Hyatt A.D. (2003) Infectious disease and amphibian population declines. Diversity and Distributions, 9, 141–150.
Gratwicke B., Evans M., Jenkins P., Kusrini M., Moore R., Sevin J. & Wildt D. (2009) Is the international frog legs trade a potential vector for deadly amphibian pathogens? Frontiers in Ecology and the Environment, 8, 438–442.
Schlaepfer MA, Hoover C, Dodd KD Jr (2005) Challenges in evaluating the impact of the trade in amphibians and reptiles on wild populations. Bioscience, 55, 256–264.
Schloegel L., Picco A., Kilpatrick A., Davies A., Hyatt A. & Daszak P. (2009) Magnitude of the US trade in amphibians and presence of Batrachochytrium dendrobatidis and ranavirus infection in imported North American bullfrogs (Rana catesbeiana). Biological Conservation, 142, 1420–1426.
Supporting evidence from individual studies
A review in 2011 (Altherr, Goyenechea & Schubert 2011) found that reducing trade in green pond frog Euphlyctis Hexadactylus and the Indian bullfrog Hoplobatrachus tigerinus through legislation allowed populations to recover from over-exploitation. Both species were categorized by the International Union for the Conservation of Nature (IUCN) as stable in the 2010 IUCN Red List. Populations of both species had crashed in India and Bangladesh following unsustainable use in the frog leg trade. Over three years of monitoring in India, it was estimated that 9,000 tonnes of frogs were removed from the wild for frogs’ legs. In 1985, green pond frogs and Indian bullfrogs were listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). India banned export of frogs’ legs in 1987 and Bangladesh followed in 1989.Study and other actions tested