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Assessment Of Invasive Pathogens In Relation To The Distribution Of Introduced Mosquitoes: Potential Threats To Biodiversity And Community Health, Tonga
Mosquitoes
Little is known about the distribution and abundance of mosquitoes throughout the Tongan archipelago, despite their close link as vectors of disease in both human and animal populations. Recent surveys in New Zealand suggest that arboviruses (arthropod borne viruses), which can be carried by mosquitoes, may be widespread and implicated in the demise of several captive and wild populations of Endangered bird species such as the New Zealand dotterel, yellowheads and yellow eyed-penguins. This has serious implications for native bird faunas elsewhere in the world, such as in Tonga, where mosquito vectors and viruses may have been recently introduced. Mosquitoes are also a vector for Dengue fever, a viral infection characterized by a rash and an aching head and joints. Dengue outbreaks have a devastating effect on the health status and economies of small Pacific island countries. Despite the existence of a “Dengue Task Force” in Tonga, no systematic surveys of mosquito distribution and abundance have ever occurred in Tonga, with only sporadic collections made prior to the 1970’s.
Project Description
EcoCARE Pacific Trust plans to identify potential mosquito related impacts on biodiversity and communities in Tonga. EcoCARE’s first objective is to quantify the distribution and abundance of invasive mosquitoes and to identify their breeding habitats. This will be done by surveying six Tongan islands; the number may increase depending on the level of support from local government agencies. This project has been funded by Conservation International’s Critical Ecosystems Partnership Fund (CEPF), with funds originally from the Australian Government’s Regional Natural Heritage Programme (RNHP) and New Zealand’s International Aid and Development Agency (NZAID).
Biodiversity Values
Located in the South Pacific Ocean, Tonga lies about 2/3 of the way between Hawaii and New Zealand. There are three groups of islands (Tongatapu, Ha’apai and Vava’u) that are made up of 170 islands giving Tonga a collective landmass of 718 km². The majority of the islands are of volcanic and raised coral origin and support a unique diversity of flora and fauna. Currently only 45 of Tonga’s 170 islands are inhabited, however, the population (approx. 100,000) is steadily growing. The principal threats to biodiversity are habitat destruction, poaching and introduced species. A less commonly cited threat to biodiversity is introduced pathogens such as arboviruses. Anthropogenic impacts have altered all inhabited ecosystems both directly (e.g. through land use changes) and indirectly (e.g. via introduced species). Nevertheless, Tonga still supports a number of unique species that are found no-where else on earth. The bird life on the islands is diverse and includes the Vulnerable bristle-thighed curlew (Numenius tahitiensis) (IUCN Red List, 2006) and the Near Threatened endemic Tongan whistler (Pachycephala jacquinoti) (IUCN Red List, 2004).
Community Outcomes
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Rubbish site - breeding sites for mosquitos (Russell Taylor) |
This project is part of a broader suite of community projects conducted in Tonga that are supported by the University of Canterbury and both the Tongan and New Zealand governments. It is anticipated that this project will provide the Tongan government, local Tongan nobles and the wider community with insights into the spread of mosquito-borne diseases and practical methods to protect themselves and the regions endemic fauna. This will be achieved through educational workshops and collaborative relationships between researchers and Tongan communities. It is intended that the work will lead to the adoption of sustainable management strategies by the local community.
Reports
Please click on this link 'A preliminary assessment of the distribution of mosquito's in the Kingdom of Tonga: potential threats to biodiversity through invasive pathogens ' to view a copy of this report.
PII contact
Dr Souad Boudjelas (s.boudjelas@auckland.ac.nz)
Please click on coloured text for links to relevant information.
Last updated 21 May 2008 |
