UK’s Overseas Territories at ongoing risk from wide range of invasive species — ScienceDaily

A new study has predicted for the first time which invasive species could pose a future threat to Britain’s ecologically unique overseas territories.

The 14 territories — many of which are small, remote islands like St. Helena and Pitcairn — are home to species found nowhere else in the world. This makes them extremely vulnerable to biological invasions – in the oceans or on land – that could lead to the extinction of these endemic species or irrevocably alter their unique ecosystems.

Researchers from the UK Center for Ecology & Hydrology (UKCEH) and Durham University, working with communities in overseas territories, have assessed thousands of potentially invasive non-native species to predict which are most likely to enter and impact those environments over the next 10 Years.

The resulting research, published in the journal Conservation Letters, provides guidance to regulators, conservation ecologists and the public to prevent these invasive alien species from becoming established and causing ecological and economic damage.

UKCEH ecologist Professor Helen Roy, who led the work, says: “These areas are exceptionally biodiverse. St. Helena, for example, has over 400 invertebrates that cannot be found anywhere else in the world – it is simply unique. We hope this study draws attention to these overseas territories and the inspiring people there who work so hard to protect their incredible wildlife and habitat.”

To create the list, experts from each British Overseas Territory worked with the broader project team of experts from around the world to predict which invasive non-native species are likely to arrive, establish and impact on biodiversity, ecosystems, human health and the economy will have the next 10 years. The report also looks at how the species are most likely to arrive, identifying shipping containers as a key route for many species.

Gibraltar and St. Helena are collectively threatened by biological invasion by most species. St. Helena is most threatened by a large number of plant species, while the Falkland Islands and Tristan da Cunha are threatened by the most sea-encroaching non-native species.

One of the invasive non-native species that could pose a threat to many of Britain’s overseas territories is the green mussel (Perna viridis). It can ‘hitchhike’ on ships and boats around the world and form dense colonies in places where it outcompetes other species, for example by reducing levels of phytoplankton – a key component of aquatic ecosystems.

Other invasive non-native species that pose a major threat to many British Overseas Territories include the small fire ant (Wasmannia auropunctata), brown rat (Rattus norvegicus) and mesquite tree (Prosopis juliflora).

dr Wayne Dawson of Durham University said: “The knowledge and experience of local experts was key to identifying the non-native species that pose the greatest threat to each territory and it was a great privilege, with a variety of contributors to collaborate on the project.”

Ecologists and other experts in the British Overseas Territories are aware of the challenges posed by invasive alien species and in many cases have robust biosecurity measures in place, but Professor Roy hopes the report will draw attention to their important work.

Professor Roy added: “Preventing the introduction of invasive alien species is crucial as managing species that have become established and widespread is often extremely expensive and in some cases no options are available. We hope this list will help drive action, including support for biosecurity activities, to protect wildlife in these precious locations.”

The 14 Overseas Territories of the United Kingdom are: Anguilla, Bermuda, British Antarctic Territory, British Virgin Islands, Cayman Islands, Montserrat, Turks and Caicos Islands, Ascension, Saint Helena and Tristan da Cunha, Falkland Islands, South Georgia and the South Sandwich Islands , British Indian Ocean Territory, Pitcairn and Gibraltar. A total of 147 experts from 52 organizations were involved in the study, which was funded by the UK Government and led by the Alien Species Secretariat and the UK Center for Ecology and Hydrology. The research took place over 14 months and included site visits, video calls and workshops with participants. A total of 74 terrestrial invertebrates, 46 vertebrates, 71 plants and 40 marine species were included in the high-risk lists. Funding: We thank the UK Government, the Foreign, Commonwealth and Development Office Conflict, Security and Stabilization Fund and the GB Non-Native Species Secretariat (GB NNSS) for the opportunity to conduct this research.