LIFE TRACHEMYS - Demonstration strategy and techniques for the eradication of invasive freshwater turtles

LIFE09 NAT/ES/000529

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Contact details:

Project Manager: José Ignacio LACOMBA
Tel: +34 96 1973604
Fax: +34 96 1973877
Email: lacomba_ign@gva.es

Project description:


The pet turtle trade has led to a large number of specimens being maintained in captivity. Often these are released thoughtlessly into the wild, where they can start breeding and competing with native species. Exotic turtles can also be vectors of several pathogen agents that can be transmitted to other turtles. These issues can exacerbate efforts to conserve endangered native turtle species, such as the European pond turtle (Emys orbicularis).


The main aim of this LIFE+ Biodiversity project was to address the negative environmental impacts on wetland environments from alien exotic turtle species, particularly the red-eared slider (Trachemys scripta). A strategy was planned to preserve endangered endemic fish and autochthonous freshwater turtles in Valencia and Portugal by eradicating wild populations of exotic invasive freshwater turtles. Regulations were anticipated to tackle the trade and use of exotic invasive turtles as pets and prevent their release into the wild. A public awareness campaign was also to be established to support the regulations. This would highlight the problems and damage caused by exotic invasive species in order to deter people from buying or releasing exotic turtles. A key aim focused on assessing opportunities for replicating the project results elsewhere.

Expected results included:

  • Development of standardised protocol methods and techniques for the eradication of exotic invasive freshwater turtle populations in wetlands;
  • Implementation of the protocol in pilot areas (natural wetlands in Spain and Portugal);
  • Demonstration of the viability and feasibility of new techniques for detecting nesting areas of exotic invasive freshwater turtle populations in wetlands;
  • Collection of individual exotic turtles (mainly T. scripta) from 17 wetlands of Valencia and Portugal;
  • Eradication of eggs of exotic turtles (mainly T. scripta) from 11 wetlands of Valencia and Portugal;
  • Eradication of wild populations of exotic invasive freshwater turtles from 17 natural wetlands in Spain and Portugal;
  • Production of a handbook about the eradication of exotic invasive freshwater turtle populations in wetlands;
  • Reinforcement of 10 populations of indigenous endangered freshwater turtles in Valencia and Portugal;
  • Holding an international seminar about the control of invasive exotic fauna in wetlands.


The LIFE TRACHEMYS project successes included halting the loss of freshwater biodiversity caused by invasive turtles species, mainly T. scripta. The threat was not removed altogether though and Afterlife proposals acknowledge the need for continued eradication action into the long term. Nevertheless, a significant amount of progress was achieved and evidence from the project’s seven locations showed that at:

  • Peñíscola marshes - a reduction in the number of captures of exotic turtles was observed, while catches of native species (especially Mauremys) increased;
  • Almenara marshlands - continued efforts to remove T. scripta specimens and to destroy nests of this species is reflected in the low number of neonates present and, therefore, in a reduction in the capture of exotic turtles;
  • Marjal dels Moros – numbers of catches of exotic species stablised or fell. A mixed nesting area of Emys, Mauremys and T. scripta was detected which is under surveillance and control. The populations of native turtles are in good condition with signs of recovery (increase of nests and juveniles);
  • Marsh of Rafalell i Vistabella – monitoring work successfully verified the reproduction of Emys that had been reintroduced;
  • P. N. L'Albufera - biodiversity have increased in the Natural Park thanks to reintroduction works by action C8 (Tancat de la Pipa and Tancat de Milia);
  • Albufera Gaianes - the population of exotic turtles has been reduced and the reintroduction of Mauremys has started;
  • Portugal – four sites are expected to benefit in the medium term from eradication work targeting exotic turtles. Problems still exist with T. scripta reproduction, but the number of nests, juveniles and adults is low.
  • The sustainability of important EU habitats and species in wetlands has also been safeguarded thanks to the provision of the project’s eradication strategy concerning wild populations of exotic invasive freshwater turtles. This has set in place a robust set of conservation measures supporting existing populations of endangered endemic fish and autochthonous freshwater turtles.

    Public awareness campaigns form part of the strategy and the project’s information actions helped to improve stakeholders’ appreciation about the problems and damage that can be caused when invasive alien species are released into the wild. Other positive socio-economic impacts relate to the project’s ability to mobilise large numbers of NGOs and volunteers. This has been especially important since it created a wide network of external collaborators who have become involved in practical nature conservation.

    Such a critical mass of voluntary support is considered to be a success factor for projects of this type. Providing the volunteers with well-tested trapping tools (at the right time and in the right environmental conditions) is noted as an additional success ingredient. Checks should also be made to determine the effects of trapping techniques in different areas.

    Demonstration work carried out during the project to test the potential replication of these methodologies highlighted good practices that could be transferred elsewhere. They included capturing and monitoring, radio-tracking of T. scripta specimens or rifle hunting. A novel floating bait trap proved to be the best method of capture. It is more cost-effective and extremely selective so reduces risks to non-target species. ‘Rapid response’ principles were also shown to deliver good value for money in terms of economic and environmental cost savings.

    Lessons were learned about innovative techniques (like using Geo radar or dog training to detect nests) that did not perform as well as planned.

    It was not possible to implement specific regulations designed to avoid the trade and use of exotic invasive turtles as pets and its final release into the wild.

    Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).


Environmental issues addressed:


Biodiversity issues - Invasive species
Habitats - Freshwater
Species - Reptiles


endangered species‚  wetland

Target EU Legislation

  • Nature protection and Biodiversity
  • Directive 79/409 - Conservation of wild birds (02.04.1979)
  • Directive 92/43 - Conservation of natural habitats and of wild fauna and flora- Habitats Directiv ...
  • Decision 93/626 - Conclusion of the Convention on Biological Diversity (25.10.1993)
  • COM(95) 189 - "Communication on the judicious use and conservation of wetlands" (12.12.1995)
  • COM(98)42 -"Communication on a European Community Biodiversity Strategy" (05.02.1998)
  • COM(2001)162 -"Biodiversity Action Plan for the conservation of natural resources (vol. I & II)" ...
  • Development of new legislation

Target Habitat types

  • 02 - Specific (i.e.for technical reasons or specific issue)

Natura 2000 sites

SCI ES0000023 L'Albufera
SCI ES0000148 Marjal dels Moros.
SPA PTZPE0017 Ria Formosa
SCI ES5213024 Tabarca
SCI ES5223007 Marjal d'Almenara
SCI PTCON0013 Ria Formosa/Castro Marim
SCI ES5222002 Marjal de Peníscola
SCI ES5222005 Marjal de Nules
SCI ES5233030 Marjal de la Safor



Coordinator Conselleria de Infrastructuras, Territorio y Medio Ambiente - Generalitat Valenciana
Type of organisation Regional authority
Description The co-ordinating beneficiary, Generalitat Valenciana (Conselleria de Medi Ambient), is the responsible for environmental protection in the Autonomous Community of Valencia.
Partners CIBIO-ICETA (Centro de Investigação em Biodiversidade e Recursos Genéticos-Instituto de Ciências e Tecnologias Agrárias e Agro-alimentares-Universidade do Porto, Portugal Parque Biológico de Gaia, Portugal ALDEIA-RIAS-Centro de Recuperación e Investigación de Animales Salvajes-Ria Formosa, Portugal


Project reference LIFE09 NAT/ES/000529
Duration 01-JAN-2011 to 30-DEC -2013
Total budget 1,200,754.00 €
EU contribution 591,390.00 €
Project location Comunidad Valenciana(España) Norte(Portugal) Algarve(Portugal)


Read more:

Leaflet "Problemàtica de les tortugues exòtiques [Catalan ...
Leaflet "Environmental impact of exotic turtles" (1.06 MB)
Leaflet "Problemática de los galápagos exóticos" (1.24 MB)
Leaflet "Recuperació de la fauna autòctona en perill : Tor ...
Leaflet "Recuperación de fauna autóctona en peligro : Galá ...
Leaflet "Recovering our endangered native fauna : European ...
Leaflet "Problematica e controlo de cagados exoticos insor ...
Photos Chapa
Poster "Autocolhante : Mauremy leprosa" (2.18 MB)
Poster "Autocolhante : Trachemys scripta" (2.68 MB)
Poster "Pegatina : Emys orbicularis" (2.62 MB)
Poster "Pegatina : Mauremys lerposa" (2.16 MB)
Poster "Pegatina : Trachemys scripta" (2.67 MB)
Poster "Autocolhante : Emys orbicularis" (2.66 MB)
Project web site Project's website
Project web site - 2 Facebook page of the project
Publication: After-LIFE Conservation Plan Informe Post-LIFE
Publication: After-LIFE Conservation Plan After-LIFE Conservation Plan
Publication: Book "Mauro e Emilia : os nossos cagados estao em perig ...
Publication: Layman report Layman report (Portuguese version)
Publication: Layman report Layman report
Publication: Layman report Informe layman


Project description   Environmental issues   Beneficiaries   Administrative data   Read more   Print   PDF version