Return to World Chelonian Trust Main Page for more Turtle and Tortoise Information

Declared Turtle Trade From the United States


Issues - Results of the Turtle Trade  - Feral Population Threats


There are a vast number of issues that the trade in turtles initiates. As has been mentioned elsewhere in this work one of the issues is fear of feral populations  becoming established of species massively produced and exported  from the United States.   The impact of feral populations on native species has not been adequately researched.  One difficulty of this type of research is separating correlation from causation.  If there is loss of a native population at the same time as a foreign population becomes established the immediate suspicion is that the native population has been negatively impacted by the presence of the non native species.  Many other possibilities exist for such a situation,  increased pollution adversely affecting native species more than the non native ones or a change in the habitat is just two of the possibilities. 


Having said the above it is likely that  American species can survive in various areas of the world, if they survive and establish sustaining breeding populations this may impact native species by competition for nesting areas,  basking spots,  food resources,  non native disease transmittance or stress issues.


It is a foregone conclusion that feral populations of massively produced American species will become established,  there are presently many colonies of Trachemys scripta throughout the Untied States outside of their native range, in addition there are Trachemys in feral populations in South East and Far East Asia, Europe, the Caribbean, New Zealand, Israel, Bahrain, Mariana Islands, Guam and South Africa. They are a classified as a Class 1 Threat by Australia. See the resources below for more information on this topic.  (external hyperlinks will open in a new window) These  resources only relate to Trachemys.


Further reading -- Thanks to the IUCN Invasive Species Specialist Group (ISSG) for the following resources from their database 


1. Acuna-Mesen and Rafael Arturo, 1992. Potential exploitation of captive Slider Turtles (Trachemys scripta) in Costa Rica: A preliminary study. Brenesia. 0(38).157-158.
Summary: Report from Costa Rica.

2. Agosta et al., 1999. Autoecology and synecological relationships in populations of Trachemys scripta elegans introduced in Lombardy. Preliminary data. Rivista di Idrobiologia. 38(1-3). Gennaio-Dicembre, 1999. 421-430.
Summary: Reports of Trachemys scripta elegans in Italy.

3. Aliens 19 & 20, Double issue. 2004. Invasive Species Specialist Group of the IUCN Species Survival Commission. ISSG, Auckland, New Zealand.
Summary: Interesting and timely information on invasive species and associated issues. Focuses on conservation issues and includes news of upcoming conferences, publications, and reports.

4. Chen and Lue, 1998. Ecological notes on feral populations of Trachemys scripta elegans in northern Taiwan. Chelonian Conservation & Biology. 3(1). Aug., 1998. 87-90.
Summary: Report from Taiwan.

5 Fimrite, P. 2004. Turtles battle for Marin turf. San Francisco Chronicle. 17 May 2004.

6 Gianaroli, et al., 1999. Problems of conservation of the European pond turtle in Modena. The case of the Villa Sorra park. Atti della Societa Dei Naturalisti e Matematici di Modena. 130 1999. 115-124.
Summary: Reports of Trachemys scripta elegans in Italy. Abstract

7 Moses Kairo and Bibi Ali, 2003. Invasive Species Threats in the Caribbean Region. Report to the Nature Conservancy. CAB International, Trinidad & Tobago.
Summary: Information on threats posed by invasive species in the insular Caribbean.

8 Najbar and Bartlomiej, 2001.The red-eared terrapin Trachemys scripta elegans (Wied, 1839) in the Lubuskie province (western Poland). Przeglad Zoologiczny . 45(1-2). 2001. 103-109.
Summary: Spread of Trachemys scripta elegans in Poland. Abstract .

9 NRM&E, Red-eared slider turtle.
Summary: Factsheet- Queensland Australia.

10 Piovano, et al., 1999. Trachemys scripta elegans monitoring in Torino urban park. Rivista di Idrobiologia. 38(1-3). Gennaio-Dicembre, 1999. 499-508.
Summary: Red-eared slider population monitoring. Abstract

11 ROK Wetlands Part 1
Summary: Report from Republic of Korea.

12. ROK Wetlands Part 2
Summary: Report from Republic of Korea.


Return to Start:  Declared Turtle Trade From the United States

World Chelonian Trust

PO Box 1445

Vacaville, CA