The Tourist Trap : Galapagos victim of its own success

Aug. 12, 2009 - PRLog -- Andrew Cunningham, a senior scientist at ZSL Institute of Zoology and a co-author of the study says: “Our research has shown that everything is in place for a similar disaster to occur in Galapagos as occurred in Hawaii.  Unless immediate and forceful mitigating actions are taken, it is only a matter of time before Galapagos wildlife meet the same fate as the Hawaiian honeycreepers.”

The southern house mosquito, Culex quinquefasciatus, was previously thought to have been introduced to the Galapagos in a one-off event in the mid-1980s.

However, scientists from the University of Leeds, the Zoological Society of London (ZSL), the University of Guayaquil, the Galapagos National Park and the Charles Darwin Foundation, have shown that the mosquito is regularly hitching a ride from the mainland and breeding with existing populations.

The sinister stowaways are also island hopping on tourist boats, meaning that incursions of mosquito-borne diseases are likely to spread throughout the archipelago.

Arnaud Bataille, a Leeds-ZSL PhD student who carried out the work said, “Our research consisted of looking for insects in aircraft holds and genetic analysis of the mosquito populations. The former allows us to quantify the arrival rates of mosquitoes on aeroplanes, and the latter allow us to estimate how many survive and spread around the islands once in Galapagos. On average the number of mosquitoes per aeroplane is low, but many aircraft arrive each day from the mainland in order to service the tourist industry, and the mosquitoes seem able to survive and breed once they leave the plane.”

The southern house mosquito is an important carrier of diseases such as avian malaria, avian pox and West Nile fever. Its introduction to Hawaii in the late 19th Century had a devastating effect on the islands' endemic birds. Only 19 out of 42 species and subspecies of honeycreeper now remain, and many of the extinctions are considered to have been caused by diseases spread by the mosquito.
 
Tourism is a major source of income for the Galapagos, providing funding for the National Park and Marine Reserve which protect the islands’ wildlife.  

This new research highlights how the cost of tourism could outweigh its benefits if the constant threat of introduced disease pathogens remains unchecked.
   
“Few tourists realise the irony that their trip to Galapagos may actually increase the risk of an ecological disaster,” says Leeds University’s Simon Goodman, one of the authors of the study.

“That we haven’t already seen serious disease impacts in Galapagos is probably just a matter of luck. The Ecuadorian government recently introduced a requirement for all aircraft flying to Galapagos to have insecticide treatment, but the effectiveness hasn’t yet been evaluated, and similar measures still need to be introduced for ships. With tourism growing so rapidly, the future of Galapagos hangs on the ability of the Ecuadorian government to maintain stringent biosecurity protection for the islands.”

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Editorial Notes

1. The research paper, Evidence for regular ongoing introductions of mosquito disease vectors into the Galapagos Islands (DOI:10.1098/rspb.2009.0998) is published online in Proceedings of the Royal Society B: Biological Sciences.  Advanced copies of the paper are available on request from the ZSL press office.

2. The research was carried out in the Genetics, Epidemiology and Pathology Laboratory of the Galapagos National Park, Ecuador; the University of Leeds, UK; and the Natural Environment Research Council’s Molecular Genetics Facility at the University of Sheffield, UK.

3. The work was funded by the UK government’s Darwin Initiative scheme, grants 162-12-17 and EIDPO15, by the ‘AGAPE’ Marie Curie Training Centre grant awarded to the University of Leeds Faculty of Biological Sciences, and the Natural Environment Research Council. The research forms part of Arnaud Bataille’s PhD thesis to determine the impact of mosquitoes and their role in the emergence of diseases that could threaten Galapagos biodiversity.

4. The Genetics, Epidemiology and Pathology Laboratory of the Galapagos National Park was established in 2004 with funding from the UK government’s Darwin Initiative to the Galapagos National Park, the University of Guayaquil (Ecuador), the Zoological Society of London and the University of Leeds.  The laboratory was set up to identify and control disease threats to Galapagos wildlife.

5. The Faculty of Biological Sciences at the University of Leeds is one of the largest in the UK, with over 150 academic staff and over 400 postdoctoral fellows and postgraduate students.  The Faculty is ranked 4th in the UK (Nature Journal, 457 (2009) doi:10.1038/457013a) based on results of the 2008 Research Assessment Exercise (RAE).  The RAE feedback noted that “virtually all outputs were assessed as being recognized internationally, with many (60%) being internationally excellent or world-leading” in quality.    The Faculty’s research grant portfolio totals some £60M and funders include charities, research councils, the European Union and industry.  www.fbs.leeds.ac.uk

6. Founded in 1826, the Zoological Society of London (ZSL) is an international scientific, conservation and educational charity: our key role is the conservation of animals and their habitats.  The Society runs ZSL London Zoo and ZSL Whipsnade Zoo, carries out scientific research in the Institute of Zoology and is actively involved in field conservation in other countries worldwide. For further information please visit www.zsl.org

7. The two other mosquito species in Galapagos are Aedes taeniorhynchus (the black salt-marsh mosquito) and Aedes aegypti. Aedes taeniorhynchus, is the only mosquito that colonised naturally Galapagos and has adapted to its specific environment. It has a wide host range, as it adapted to feed on Galapagos reptiles (tortoise, iguana) in addition to mammals and birds. For these reasons, it may play a major role in wildlife disease transmission in Galapagos. For further information on this mosquito, please read the research paper, Natural colonization and adaptation of a mosquito species in Galapagos and its implications for disease threats to endemic wildlife (DOI: 10.1073/ PNAS.0901308106).  

Aedes aegypti arrived in the mid-1990s but this species is not such a great concern for wildlife because it specialises in feeding on humans. However, it is a concern for human health, particularly because it transmits Dengue fever, a debilitating viral illness.

8. The Galapagos Islands and their flora and fauna are famous for the role they played in inspiring Charles Darwin’s thinking on the theory of evolution by natural selection. Discovered in 1535 by the 4th Bishop of Panama after his ship drifted off course, the archipelago consists of 13 main islands, 6 smaller islands, and 107 islets.  Administered by Ecuador, the islands straddle the equator in the Pacific, 1000km from the continent. Around 90% of the land area of the archipelago is national park, and a zone extending 40km offshore from the islands is a marine reserve, forming one of the largest marine protected areas in the world.

Galapagos is most famous for its endemic reptiles (11 sub-species of giant tortoise; 3 species of land iguana and the world’s only species of sea going lizard, the marine iguana; 7 species of lava lizard; 5 endemic and 1 native species of gecko), terrestrial birds (22 endemic species), and large sea bird colonies (including the only penguins and albatrosses found on the equator, and the worlds only flightless cormorant species).

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Founded in 1826, the Zoological Society of London (ZSL) is an international scientific, conservation and educational charity: our key role is the conservation of animals and their habitats. For further information please visit http://www.zsl.org