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Antarctic Environments Portal

Status of known non-native species introductions and impacts

Hughes Thumb EN

Information Summary

Version: 1

Published: 21/08/2015 GMT

Reviewed: 21/08/2015 GMT

Authors

Kevin A. Hughes* and Yves Frenot**

* British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB30ET, United Kingdom
** French Polar Institute Paul Emile Victor, Plouzané, France

kehu@bas.ac.uk

DOI: 10.18124/D4G59G


Synopsis

Antarctic biodiversity and ecosystems are under threat from introduced non-native species.  Major invasion impacts in the sub-Antarctic region provide some indication of potential changes to ecosystem structure and function that could occur within the Antarctic Treaty area in the future.  As yet, Antarctica has few known non-native species compared to other areas, with the Antarctic Peninsula and off shore islands the most invaded regions so far.  However, invasion impacts are likely to increase, facilitated by climate change and increased human activity in the region.  Some established non-native species have already begun to increase their distribution within Antarctica with potentially negative impacts upon native organisms and habitats.  Further scientific research could usefully investigate the rate and extent of microbial and marine introductions, rates of transfer of native and non-native species between Antarctica eco-regions, and devise optimal eradication methodologies and risk assessment protocols.


Summary

Invasive non-native species have caused substantial negative impacts on biodiversity and ecosystem structure and function in many areas of the Earth including the sub-Antarctic region (considered as an associated and dependent ecosystem by the Treaty) where over 200 non-native species have been introduced (1).  Substantial biodiversity and ecosystem structural changes on some sub-Antarctic islands show what may happen in Antarctica as climate changes and levels of human activity continue to increase (1,2).  Antarctica currently has few known terrestrial non-native species, with those reported mostly limited to flowering plants and invertebrates (Figure 1 and 2; 1,3,4).  Nevertheless, recent monitoring activities have increased our understanding of species number and distribution (5,6).

 

Hughes Figure 1

Figure 1. Map of the Antarctic Peninsula region showing the distribution of known non-native vascular plant (■) and invertebrate (●) species (see Resources for more details).

 

Hughes Figure 2

Figure 2. [A] Nassauvia magellanica eradicated from Deception Island in January 2010 (Photo: K. A. Hughes). [B] Trichocera maculipennis found in Artigas Station (King George Island, South Shetland Islands) sewage system in 2006/07 and now found in surrounding terrestrial habitats (Photo: O. Volonterio). [C] Non-native potted plant in the window of an Antarctic research station (King George Island) (Photograph: K. A. Hughes]. [D] Poa annua on Deception Island which was subsequently removed (Photo: M. Molina-Montenegro). [E] Poa pratensis on Cierva Point, Antarctic Peninsula, where it was first introduced during transplantation experiments in 1954/55 and removed in 2015 (Photo: L. R. Pertierra). [F] Non-Antarctic soil inadvertently introduced to Rothera Research Station, Antarctic Peninsula, on vehicle wheels (Photo: K. A. Hughes). [G] Hull fouling of ships is a pathway for introduction of non-native marine species to Antarctica (Photo: K. A. Hughes). (H) The flightless chironomid midge Eretmoptera murphyi, introduced to Signy Island, South Orkney Island from South Georgia (Photo: P. Bucktrout). [I] Elephant seal (Mirounga leonina) resting in the drainage channel below the sewage treatment plant outfall at Rothera Research Station. Although the sewage is treated, microbial loads can still be high depending on the efficiency and performance of the sewage treatment plant. The effect of sewage ingestion by Antarctic marine mammals and avifauna is largely unknown. [Photograph: K.A. Hughes]

Most non-native species have been introduced unintentionally through importation of cargo, fresh foods, clothing and personal effects (1,3,7,8).  Some non-native species have been found on Antarctic stations and in hydroponic facilities (1).  For example, insects persist in some station sewage systems, despite eradication attempts, and may disperse to establish in the local environment (4,9).

Little is known about levels of non-native species introductions to Antarctic marine environments but species could be imported in ballast water or on ship hulls (1,10).  The introduction of non-native microorganisms is also little understood but may affect wildlife health (11) and allow the introduction of novel genetic material into native microbial communities, with unforeseen consequences for microbial community structure and function (12).

Most known Antarctic non-native species have been found within the Antarctic Peninsula region but some have been found in other Antarctic regions (Figure 1; 1,4).  This distribution correlates strongly with areas predicted to be at greatest risk of non-native species introductions due to high levels of national operator and tourist visitation and favourable climatic conditions (8).  For example, Deception Island (South Shetland Islands) is one of the most frequently visited locations in Antarctica, but is also the most invaded, with nine non-native invertebrate species (4,8,9,13). 

Climate change and an expanding human footprint put the whole of Antarctica at increased risk of invasion (8).  Climate change may make environmental conditions more favourable for new introductions and increase the likelihood that established non-native populations will increase their distribution and capacity to compete with native species (3,5).  Human travel between Antarctic regions may transfer existing non-native species to other Antarctica areas (5).  For example, research has shown that a flightless midge (Eretmoptera murphyi), accidentally introduced to the South Orkney Islands, could survive and complete its life cycle under climatic conditions found c. 750 km further south on the Antarctic Peninsula (14).  Human activities may potentially also transfer native Antarctic species to areas within Antarctica where they are not found naturally, which could disrupt established ecosystems (15).

Not all non-native species are of equal threat to Antarctic ecosystems.  Poa annua (annual bluegrass) is invasive on most sub-Antarctic islands and has recently been described as invasive in Antarctica (1,5,16).  The variety of reproductive strategies available to this species may explain, in part, its colonisation success.  The Antarctic distribution of the grass has increased recently,having been reported from six locations on the Peninsula and South Shetland Islands, with the successful removal of small populations at four sites (5,16).  Genetic studies of Poa annua from King George Island revealed that it was introduced on multiple occasions, from both European and South American sources (17).  Poa annua can have negative effects on native plant species and at one Antarctic location it has spread from its initial introduction site into the local ecosystem (5,18).

Invasive species can greatly affect ecosystem structure and function.  For example, the predatory beetle Merizodus soledadinus, accidently introduced to the sub-Antarctic Kerguelen Islands, has attacked and consumed native invertebrate populations and thereby reduced nutrient cycling in the invaded ecosystem (2).  In Antarctica, larvae of the midge Eretmoptera murphi may be able to cycle soil nutrients up to nine times faster than native invertebrate populations and, if dispersed, could alter terrestrial habitats across the Peninsula (14). 

In Antarctica, non-native species have been found mainly in the vicinity of research stations and visitor landing sites, suggesting that their presence, establishment and increase in abundance are facilitated by human activities (8,16).  For example, soil disturbance can increase the abundance and germination of non-native Poa annua, but not native plants (16).  The biology of some invasive species enables them to survive under a wide range of environmental conditions, a characteristic which may facilitate a rapid increase in their Antarctic distribution (1,8,14).  Hypogastrura viatica is the most widely dispersed non-native springtail (Collembola) in Antarctica having been found at five Peninsula locations, including popular visitor sites (4,13).  With a preference for disturbed ground, the species has already been shown to out-compete native species in the sub-Antarctic.  First reported on Deception Island in 1949, it is now found there in densities of over 5,500 individuals per litre of soil.  As yet, Hypogastrura viatica is not found on neighbouring King George Island, but high levels of human activity within the region may put this large area of ice-free ground at substantial risk of invasion (4,8,13).

Differentiating between new introductions transported through human activities (non-native species) and those introduced by wind, ocean current or wildlife (natural colonists) can be difficult (9). For example, available evidence was insufficient to ascertain categorically if the South American aster Nassauvia magellanica on Deception Island or the seeds of the rush Juncus bufonius, found within Antarctic Specially Protected Area 128 Western Shore of Admiralty Bay, were introduced by human or natural processes (9,19).  Correct differentiation is important for subsequent management as non-native species should be eradicated, according to the Protocol (9).  Within the Antarctic Treaty area, several non-native plants present as single individuals or in low numbers have been removed (4,5,9) and larger scale eradications have been initiated.  Attempts have also been made to eradicate vertebrates, invertebrates and plants on the sub-Antarctic islands, for example, reindeer and rats  on South Georgia, cats and the invertebrate Porcellio scaber on Marion Island and the grasses Anthoxanthum odoratum and Rumex crispus from Macquarie Island (1,9).

Further scientific research could usefully investigate:

  • the biology and functional characteristics of existing non-native species to determine methods for their eradication or control
  • the rate, extent and impacts of microbial and marine introductions
  • the level and impacts of transfer of native organisms between different eco-regions of Antarctica (15)

Risk assessment protocols showing which non-native species are most likely to become invasive should they be introduced have been produced for some biological groups for the sub-Antarctic, and could also be usefully developed for Antarctica (13,20).


Key Events

1962

ATCM II –WP3  Draft of Agreed Measures including first mention of prohibition on importation of non-native species

1964

Recommendation III-8  Agreed Measures for the Conservation of Antarctic Fauna and Flora which includes prohibition on bringing into Treaty area and non-indigenous animals or plants except under permit.

1991

Protocol on Environmental Protection to the Antarctic Treaty . Annex II Conservation of Antarctic Fauna and Flora  Article 4 re-iterates the prohibition on non-native species

1996

ATCM XX-IP66  First report of a non-native plant from East Antarctica

1998

ATCM XXII - IP 53  IUCN paper on  non-native species which covered pathogens, pets, household plants as well as accidental introductions around stations.

1999

ATCM XXIII - WP 32  Report on outcomes from the Workshop on Diseases of Antarctic Wildlife.

2000

Convey et al. publish “The terrestrial biota of Charcot Island, eastern Bellingshausen Sea: Antarctica an example of extreme isolation”.  Antarctic Science 12, 406-413 (2000) doi:0.1017/S095410200000047X. recognising the risk of intraregional transfers within Antarctica.

2001

Reports from an ICG provided a review and risk assessment (ATCM XXIV- WP 10)  and practical measures to reduce the risks of introducing wildlife diseases (ATCM XXIV - WP 11).

2003

Lewis et al. (10) investigated ships used in support of Antarctic science and tourism and demonstrate that non-native marine species could be transported to the Antarctic on the hulls of such vessels.

2005

ATCM XXVIII - WP 28 Suggested six measures to address the unintentional introduction and spread of non-native biota and disease to the Antarctic Treaty area  - Developing a ‘working goal’ for a quarantine strategy; Assessing the importance of pathways for introductions; Identifying risk assessment/analysis tools and methodologies; Developing specific risk-relevant pre-departure procedures; Identifying specific and practical quarantine management measures to prevent or control the spread of organisms between sites in Antarctica; Identifying priority research and monitoring requirements.

ATCM XXVIII - IP 97  Provided information on decontamination procedures for tourists.

The SCAR lecture to the ATCM highlights non-native species as a major risk to biodiversity in the Antarctic.

International Workshop on non-native species in Antarctica at University of Canterbury, New Zealand.

Frenot et al. (1) publish a review on: "Biological invasions in the Antarctic: extent, impacts and implications".

Whinam, Chilcott and Bergstrom  publish “Subantarctic hitchhikers: Expeditioners as vectors for the introduction of alien organisms”. Biological Conservation 121, 207-219 (2005) doi: 10.1016/j.biocon.2004.04.020 reporting on the potential for scientists on national Antarctic programmes to act as vectors for the introduction of Non-native Species to Antarctica.

2006

ATCM XXIX - WP 5 Rev. 1 Provided Practical Guidelines for Ballast Water Exchange to limit marine introductions, and leads to resolution 3 (2006).  

ATCM XXIX - IP 44  Details on how to manage quarantine.

ATCM XXX - IP 49   Aimed to quantify the transfers and validate the pathways for introductions

ATCM XXIX - WP 13 and ATCM XXIX - IP 46 Reports of a workshop in New Zealand on non native species and provided several recommendations:

  • non-native species should be given the highest priority; a “zero tolerance approach”
  • the CEP should take the lead and seek advice from SCAR, CCAMLR, COMNAP, IAATO, IUCN and any other appropriate organizations;
  • dedicated research was required on biological and genetic diversity, species distributions and bio-geographic zones, the potential implications of a warming climate and identification of high risk areas and ecosystems; with particular research attention to be given to microbial communities and marine ecosystems;
  • non-native species issues concerns should be built into existing procedures and practices; notably EIA procedures and the protected areas system; and
  • comprehensive and standardized guidance and/or procedures should be developed, for all operators in the Antarctic, based on a “Prevention, Surveillance, Response” approach.

2007

ATCM XXX - IP37 Reporting on hull fouling as a source of marine invasions in the Antarctic, noting that recent studies have shown hull fouling to be an important vector for non-native species introductions.

2008

ATCM XXXI - WP 16   CEP endorsed proposal to use the existing Australian Antarctic Alien Species Database for recording non-native species

ATCM XXXI - IP 17  Proposed measures to keep the Larsemann Hills free of introductions

ATCM XXXI - IP 98 COMNAP report on existing procedures to control the introduction of non-native species through logistics

The CEP adopts a five-year work plan which identifies the issue of non-native species as its highest priority issue.

2009

ATCM XXXII-IP4    SCAR included non-native species introductions in its environmental code of conduct for terrestrial scientific field research in Antarctica ATCM XXXII - IP 12  and ATCM XXXII - WP 33. Proposed provisions for inclusion in management plans for protected and managed areas

ATCM XXXII - SP 11  Secretariat topic summary of previous discussions

ATCM XXXII - WP 5 . Work Program for CEP Action on Non-native Species was agreed

An Inter-sessional Contact Group was established.

2010

ATCM XXXIII - WP 4   and ATCM XXXIII - WP 6 .  An evidence-based approach to reducing the risks of introductions 

ATCM XXXIII - WP 15  Suggestions on how to deal with the discovery of new non-native introductions

ATCM XXXIII - WP 14  The risks of intra-regional transfer of species in terrestrial Antarctica

ATCM XXXIII - IP 42 Provided details of known non-native colonists

ATCM XXXIII - IP 44. Suggested framework to determine the colonisation status of newly discovered species

2011

The CEP adopted the Non-native Species Manual (Manual) providing guidance on preventive measures to limit accidental introductions and listing a wide range of resources already published for further information.

ATCM XXXIV – WP12 COMNAP checklist for supply chain managers to ensure cargo is clean before shipping

ATCM XXXIV – WP 53  Suggestions on how to reduce risks of introductions from contaminated food ATCM XXXIV – WP25. Proposals on how to minimise risks from hydroponic facilities

ATCM XXXIV – IP50. Summary of the status of all know non-native species

2012

ATCM XXXV – WP5 . Summary of the outcomes of the IPY Aliens in Antarctica Project provided by SCAR including risk assessment

ATCMXXXV WP 42 Contained ‘Guidelines to reduce the risk of non-native species introductions to Deception Island (Antarctic Specially Managed Area No. 4)’

Terauds et al. (15) publish an analysis of the best available biodiversity data, which for the first time allows for the delineation of 15 biologically distinct ice free regions in Antarctica

2013

ATCM XXXVI- WP19  Biosecurity measures for preventing the introduction of non-native soil organisms

ATCM XXXVI – WP35 Highlighted the negative impacts of non-native microbial introductions on scientific and environmental values

2014

ATCM XXXVII - IP23  Provided up to date details of known non-native colonist

2015

ATCM XXXVIII – IP 46 Update on distribution of known non-native species