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Biological invasions in the Antarctic: Extent, impacts and implications

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Alien microbes, fungi, plants and animals occur on most of the sub-Antarctic islands and some parts of the Antarctic continent. These have arrived over approximately the last two centuries, coincident with human activity in the region. Introduction routes have varied, but are largely associated with movement of people and cargo in connection with industrial, national scientific program and tourist operations. The large majority of aliens are European in origin. They have both direct and indirect impacts on the functioning of species-poor Antarctic ecosystems, in particular including substantial loss of local biodiversity and changes to ecosystem processes. With rapid climate change occurring in some parts of Antarctica, elevated numbers of introductions and enhanced success of colonization by aliens are likely, with consequent increases in impacts on ecosystems. Mitigation measures that will substantially reduce the risk of introductions to Antarctica and the sub-Antarctic must focus on reducing propagule loads on humans, and their food, cargo, and transport vessels.
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1
Photo J.L. Chapuis
Biological invasions in the Antarctic:
extent, impacts and implications
Y. FRENOT, S.L. CHOWN, J. WHINAM, P.M. SELKIRK,
P. CONVEY, M. SKOTNICKI AND D.M. BERGSTROM
Biological Reviews 80, 45-72 (2005)
PF
60°S
Subantarctic
vs
Antarctic
1. Ecological links
2. Same operators
3. Earlier response
to environmental
changes
Guinet et coll.
Isolation
(geology, oceanography, discovery) Climatic constraints
from limit to extreme conditions
Low terrestrial biodiversity
High marine biodiversity
High endemism
Disharmony of terrestrial food webs
Example of terrestrial invertebrate communities:
dominance of decomposers,
limited numbers of obligate herbivores
near absence of predators
Relatively defenceless against changing environment
Late discovery
human influence has increased rapidly
from North to South
<1950s: commercial exploitation
(sealing, whaling, few farming activities)
mainly in the Subantarctic
>1950s (IGY + Antarctic Treaty): Scientific activities
(permanent stations)
start of human impact on the continent itself
>1980s Development of a tourist industry
mainly on the Antarctic Peninsula
Proposed definitions
Alien: introduced to an ecosystem as a result of human activity
(including species that arrive by natural means to a specific
ecosystem but are alien to that biogeographical zone)
Transient alien: survived in small populations for a short time period
but either died out naturally or was removed by human intervention
Persistent alien: survived, established and reproduced for many
years in a restricted locality, but has not expanded range from that
location
Invasive alien: spread into native communities and displaced native
species
based on Greene (1964), Walton & Smith (1973) and Richardson et al. (2000)
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Plants
HEARD
MARION
CROZET
KERGUELEN
60°S
ANTARCTIC
PENINSULA
40°S
SOUTH GEORGIA
MACQUARIE
VICTORIA LAND
33 59
13
3
69
1
0-2
How many?
2
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Most common families:
Poaceae 39 species
Asteraceae 20 species
Brassicaceae 8 species
Juncaceae 7 species
Most common alien species:
Poa annua, Poa pratensis, Cerastium fontanum, Rumex acetosella,
Stellaria media, Sagina procumbens
Life history traits:
75 % of aliens are perennial
65 % of the transient species are annual or biennial
Plants
What species?
Poa pratensis
1850 1900 1950 2000
0
20
40
60
80
100
Nombre d’espèces végétales introduites
Kerguelen
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Plants
Alfred Faure
Port-aux-Français
When?
Source: Frenot et al. 2001, Biol. Conserv. 101, 33-50.
1850 1900 1950 2000
0
20
40
60
80
100
Nombre d’espèces végétales introduites
La Possession - Crozet
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Plants
!
(
!
(
!
(
!
(
#
#
#V
!
(
!
(
!
(
!
(
#V
Sagina procumbens
Where?
1989 records
1996 records
2002 records
Huts
Permanent station
Ile de la Possession
Crozet archipelago
Source:Lebouvier et al., in prep.
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Plants
How?
Cupressus nootkatensis
Deliberate
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Plants
How? Poa annua
Accidental
Whinam et al. 2005, Biol. Conserv. 121, 207-219
Clothing and equipment of 64
expeditioners: 981 propagules and
five moss shoots
90 species from 15 families (mainly
Asteraceae and Poaceae).
163 germinations (24 species, 17 not
present in Subantarctic).
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Plants
Facilitation?
Aulacorthum solani
3
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Invertebrates
How many?
HEARD
MARION
CROZET
KERGUELEN
60°S
ANTARCTIC
PENINSULA
40°S
SOUTH GEORGIA
MACQUARIE
VICTORIA LAND
0-3
28
3
30
14
18
12
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Invertebrates
What species? Most common aliens:
Diptera
Hemiptera
Coleoptera
Most widely distributed alien species:
Psychoda parthenogenetica (Diptera Psychodidae)
Rhopalosiphum padi (Hemiptera Aphididae)
Life history traits:
Many of the aliens reproduce parthenogenetically
Myzus ascalonicus
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Invertebrates
When? Few examples documented
Falkland
Kerguelen
60°S
1912
Port - Couvreux
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Presence
Absence
N
Port-aux-Français
025 km
Port-Couvreux
Golfe du
Morbihan
Oopterus soledadinus
Kerguelen Islands
2005
King Penguin colony
tourism & scientific site
Where?
Source:Lebouvier et al., in prep.
Anatalanta aptera
Risk assessment:
Example of exotic Collembola
P. Greenslade - Pedobiologia 46, 338–344 (2002)
1. Distribution, preferred climate
2. Life history
3. Habitat
4. Ecological synchrony or tolerance
5. Dispersal mechanisms
Highest risk: the sewage springtail
Hypogastrura viatica
Quarantine controls: various types of inspection, washing procedures,
sampling and extraction procedures, fumigation…
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Vertebrates
How many?
HEARD
MARION
CROZET
KERGUELEN
60°S
ANTARCTIC
PENINSULA
40°S
SOUTH GEORGIA
MACQUARIE
VICTORIA LAND
0
6
0
12
3
1
3
4
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Vertebrates
What species? No native fish, amphibian or reptile, no mammalian
carnivore or herbivore
Deliberately introduced alien species
Fish (trout)
Mammals (reindeer, sheep, cat, rabbit)
Accidentally introduced alien species
Birds
Mammals (rats, mice)
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Microbial groups and diseases
Very little is known
Lake Vostok drilling
Gavaghan, H. (2002) Life in the deep freeze. Nature 415, 828-830.
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Microbial groups and diseases
Fungi isolated from huts at historic sites on Ross island
The Kitchen At Cape Evans
(http://homepage.mac.com/smudog/PhotoAlbum13.html)
Fungi introduced to Kerguelen and Marion Islands,now infect
the Kerguelen cabbage Pringlea antiscorbutica
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Microbial groups and diseases
Skotnicki et al., Polar Biology 26, 1-7 (2003)
Stilbocarpa Bacilliform Mosaic Virus
(Macquarie Island)
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Microbial groups and deseases
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Microbial groups and deseases
avian paramyxoviruses (APMV)
antibodies to Newcastle Disease (NDV)
Salmonella sp.
Lyme Disease spirochete, Borrelia burgdorferi
5
Current knowledge of alien species
in Subantarctic and Antarctic ecosystems
Marine introductions
Only one record : Hyas araneus
Tavares, M. & De Melo, G.A.S. 2004. Antarctic
Science 16, 129–131.
Photo http://www.seawater.no/fauna/Leddyr/sandpyntekrabbe.htm
Whinam et al. 2005, Biol. Conserv. 121, 207-219
Inspection of a barge used by AAD at Heard and Macquarie Islands:
Algae (Ulva sp.)
• Barnacles
Live crustaceans
•Starfish
Live mussels
Live crabs See also Lewis et al. 2003 Marine Pollution Bulletin 46, 213–223
Origins of invasion
Most aliens are of European origin,
large ecological range
Few exceptions:
Carabid beetles native to the Falkland Islands
Trechisibus antarcticus ÆSouth Georgia
Oopterus soledadinus ÆKerguelen, South Georgia
Trechisibus antarcticus
Photo P. Convey
Trisetum spicatum
Bipolar plant species, present in the Falkland Islands
Trisetum spicatum ÆKerguelen
Correlates of invasion
Biological traits: e.g. parthenogenesis, long-lived species
Size of the islands
Distance to the nearest continent
Absence of many functional groups
Level of human occupancy or human visitor frequency
Energy availability
Human pattern of use
• Climate Level of introduction
of alien biota
Over-riding influences
Changing pattern of use
Tourism
Mainly around the Scotia Arc and Antarctic Peninsula, to a lesser
extent in the Ross sea sector
Sequence of sites visited is often from warmer, higher biodiversity
areas to cooler, lower biodiversity areas
Source www.iaato.org
Changing pattern of use
Tourism
Four trends in tourism patterns of significance to aliens:
1) Disproportionately attracted to sites of high/medium diversity
2) Intensity of visitor use is increasing
(number of people landing, number of rubber boat…)
3) Most popular sites of popularity change over time
4) The range of tourist activities is expanding
(landing and wildlife watching, walks, kayaking trips,…)
Changing pattern of use
Scientific research activities
2001/02 season
Æ4390 personnel in Antarctica + Subantarctic islands, across 67
stations or field camps (COMNAP, 2003)
Æ
13600 tourists (IAATO, 2002), landings at 118 sites on the Antarctic
Peninsula and South Shetland Islands (Moser & Betts, 2002)
~ 1361 Scotia Arc and Antarctic Peninsula
~ 1200 McMurdo Station, Ross sea sector
60 ships used by national programs to transport personnel and cargo
6
Ex: house fly via British airlink
Falkland Islands ÆRothera Point
ÆKillingbeck Isl. (mid-January 2003)
Changing pattern of use
Accessibility by air
Faster, more efficient exchange of
personnel and equipment
but allows rapid transfer of
propagules (short-life stages arrive
alive)
Climate change: trends
Temperature change for Austral Winter, 1950-2005
(NASA-GISS)
Annual air temperature > 1 °C
over the last 30-50 years
Changes in precipitation
Changes in water availability in
terrestrial habitats
Glacial retreat: new areas for colonisation
Climate change: implications for alien biota
Calliphora vicina
Accumulated degree days / year at Kerguelen Islands
400
500
600
700
800
900
52 6055 65 70 75 80 85 90 95 2000
400
500
600
700
800
900
52 6055 65 70 75 80 85 90 95 2000
First record at KerguelenFirst record at Kerguelen
611
Minimum accumulated degree days necessary to complete
the life cycle of Calliphora vicina, vitellogenesis included
Establishment and colonisation of new alien species
0102030 Km
Port aux Français
Calotte
Cook
N
Iles Kerguelen
49° S
69° E
Vallée
Ampère
0102030 Km
Port aux Français
Calotte
Cook
N
Iles Kerguelen
49° S
69° E
Vallée
Ampère
Climate change: implications for alien biota
Calliphora vicina
Establishment and colonisation of new alien species
Maritime Antarctic and continental coastline
Temperature, precipitation, UV-B
Extent of existing populations of persistent aliens
Impacts likely continue to be minor, but poorly understood;
further alien colonization (including microbial groups)
expected
Victoria Land Dry Valleys (continental Antarctic)
Short term cooling reported but disputed
UV-B receipt during ozone depletion
No alien species known to be established; likely increase in
arrivals and establishment of alien micro-organisms
•Dome C•Dome C
Concordia station
75°06’S - 123°21’E
February 2006
7
CONCLUSIONS
1. At present macro-alien biota confined to sub-Antarctic and
to a much lesser extent maritime Antarctic
2. Impacts of alien taxa on indigenous ecosystems range from
negligible / transient to significant
3. The majority of aliens are representatives of widespread families
and/or are European in origin
CONCLUSIONS
4. Major correlates of invasion are human visitor
numbers/frequency and temperature.
5. Risks of introductions to region, although lower than elsewhere,
remain significant.
6. Current climatic trends will further enhance alien invasion.
CONCLUSIONS
7. Unless stringent measures are taken to reduce propagule loads
new invasions will occur, with impact
key areas: humans, their food, cargo, transport vessels
8. A clear and urgent need for long-term monitoring programmes
a) identify and assess future invasions,
b) monitor the status of species already established
c) assess the effectiveness of any mitigation measures adopted
CONCLUSIONS
Consider / recommend
on a range of further mitigation measures:
cessation of imports / on-station cultivation of foreign biological
material
stringent measures to ensure rodent-free status of ships and aircraft
logistical planning to minimise the risk of intra-regional and local
transfer of propagules to pristine locations
control of visitor numbers and access to more sensitive or pristine
sites
cleaning/sterilization of high risk transport locations for aliens, e.g.
cargo surfaces, foodstuffs and clothing
Establishment of a Code of Conduct for field work:
Transfer of alien species to Antarctica and Subantarctic islands
and between location transfer of species (RiSCC)
Evolution and Biodiversity in the Antarctic: the
Response of Life to Change (EBA)
describe the past,
understand the present,
predict the future ...
8
Photo K.Pierre / IPEV
Support
French Polar Institute (Programme 136)
CNRS (Zone-atelier de recherches sur l’environnement antarctique et subantarctique)
Spatial, Physiological and Conservation Ecology Group, Dept Zoology, University of
Stellenbosch
NRF Centre for Invasion Biology, Tasmanian Nature Conservation Branch, Macquarie University
British Antarctic Survey (BIRESA Project)
Australian National University (Canberra)
Australian Antarctic Programme (Project 1015 and 1187),
Australian Antarctic Division
Thank you
Code of Conduct to minimise the chance of introduction of alien taxa to
Antarctic and subantarctic environments and to reduce the risk of
accidental transfer of taxa between major ice-free localities
Risk assessment
•Has any equipment/ equipment cases/ field clothing/ boots,
planned for use in the subantarctic/Antarctica been used in
other natural environments, particularly alpine or polar
environments?
•What are the means needed to clean this equipment/
equipment cases/ clothing/boots?
•Will the field party be visiting more than one major locality?
If yes, how will the field party ensure that equipment/ equipment cases/
clothing/boots do not carry diaspores between sites?
Code of Conduct to minimise the chance of introduction of alien taxa to
Antarctic and subantarctic environments and to reduce the risk of
accidental transfer of taxa between major ice-free localities
Field work
Field planning
If field work requires moving between major ice-free localities, aim to
conduct field work in low diversity localities before high diversity localities.
Equipment
When designing field equipment, reduce the capacity of the equipment to
carry additional material and make the equipment easy to clean and sterilise.
If equipment can not be cleaned effectively, do not use this equipment
between major localities but take multiple sets of equipment (eg planktonic
nets).
Be aware of where equipment cases are stored and that these cases do not
accumulate dust or invertebrate infestations.
When cleaning items be particularly vigilant in removing soil, seeds and
bryophyte propagules (including leaves).
Outdoor clothing and boots and packs
•If clothing can not be cleaned with bleach or similar compound, take
new clothing/boots and packs. Be aware that items with Velcro can
collect seeds. Chose items with minimal or no velcro.
•Clean field items between sites. Be particularly vigilant in removing soil,
seeds and bryophyte propagules (including leaves).
Code of Conduct to minimise the chance of introduction of alien taxa to
Antarctic and subantarctic environments and to reduce the risk of
accidental transfer of taxa between major ice-free localities
Key questions:
1. State of knowledge:
How complete is the understanding of non-native species in Antarctica?
What are the gaps in knowledge?
What are the research priorities?
2. Non-native species threats:
What are the key characteristics of successful invasive species?
Which species, diseases or groups pose the greatest threat in Antarctica? (including
current identified diseases)
Which environments or ecosystems are most at risk?
What are the transport processes / pathways?
How do we distinguish between natural and human-assisted invasions? And how do we
respond?
Genetics threats? (Which may result from exchanges of individuals between sites in
Antarctica).
UNDERSTANDING THE THREAT
introduce the current state of knowledge regarding biological invasions in
Antarctica, and in a global context
provide background for key questions 1 and 2
... Despite only covering <1% of the continent (Brooks et al., 2019;Burton-Johnson et al., 2016), permanently ice-free land provides crucial habitat for most of Antarctica's terrestrial biodiversity, including its iconic seabirds . Ice-free areas occur as coastal oases, cliffs, or nunataks, and often form small patches or islands of rock and soil (habitat islands; Frenot et al., 2005) in a matrix of ice or snow. Under moderate to severe climate forcing scenarios (RCP4.5; ...
... Antarctica's ice-free areas are often isolated islands in a sea of ice and snow (Frenot et al., 2005;Lee et al., 2017). As ice-free areas expand in size and new patches emerge, the distance between patches will decrease, thus increasing connectivity (Lee et al., 2017). ...
... Thus, even if a non-native species dispersed, or was transported, to the white continent they often lack the capacity to survive its harsh environment (Barnes et al., 2006;Bergstrom et al., 2006;Hughes et al., 2006). However, as climate conditions become milder, this barrier will weaken and species previously unable to establish may now be able to take hold (Barnes et al., 2006;Bergstrom, 2022;Duffy et al., 2017;Frenot et al., 2005;Holland et al., 2021). This reality is reflected in both current observations of non-native species spread and in projections for the future. ...
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Antarctic biodiversity faces an unknown future with a changing climate. Most terrestrial biota is restricted to limited patches of ice‐free land in a sea of ice, where they are adapted to the continent’s extreme cold and wind and exploit microhabitats of suitable conditions. As temperatures rise, ice‐free areas are predicted to expand, more rapidly in some areas than others. There is high uncertainty as to how species’ distributions, physiology, abundance and survivorship will be affected as their habitats transform. Here we use current knowledge to propose hypotheses that ice‐free area expansion i) will increase habitat availability, though the quality of habitat will vary; ii) will increase structural connectivity, although not necessarily increase opportunities for species establishment; iii) combined with milder climates will increase likelihood of non‐native species establishment, but may also lengthen activity windows for all species; and iv) will benefit some species and not others, possibly resulting in increased homogeneity of biodiversity. We anticipate considerable spatial, temporal, and taxonomic variation in species responses, and a heightened need for interdisciplinary research to understand the factors associated with ecosystem resilience under future scenarios. Such research will help identify at‐risk species or vulnerable localities and is crucial for informing environmental management and policymaking into the future.
... This is especially so for sub-Antarctic ecosystems which are characteristically simple and lack representatives of many functional groups (Vernon et al. 1998;Chown and Convey 2016;. Consequently, in sub-Antarctic ecosystems not only do invasive mammalian predators have particularly devastating consequences (Courchamp et al. 2003;Frenot et al. 2005;Angel et al. 2009), but so can invasive invertebrate predators, pollinators, herbivores, and macro-detritivores (Jones et al. 2003;Smith 2007;Chown et al. 2008;Greenslade et al. 2007Greenslade et al. , 2008Convey et al. 2010;Lebouvier et al. 2020), although more research into the extent of such impacts is required (Houghton et al. 2019a). ...
... Yet K. andersoni has overcome this barrier, dispersing kilometres from its east coast introduction site to colonise the west coast of the island. Humans are important vectors of non-native plant and invertebrate propagules to Antarctica and sub-Antarctic islands (Frenot et al 2005;Chown et al. 2012;Houghton et al. 2016;Duffy and Lee 2019). Human activities also drive intra-regional transfer of propagules within Antarctic sites and sub-Antarctic islands (Lee and Chown 2011;Hughes et al. 2019;Bartlett et al. 2020;Lebouvier et al. 2020). ...
... Bokhorst et al. 2008;Janion et al. 2010;Nielsen and Wall 2013;Andriuzzi et al. 2018). Furthermore, warming climate is predicted to drive expansion of existing non-native species and see the arrival and expansion of new non-native species; plants (Pertierra et al. 2017;Molina-Montenegro et al. 2019; March-Salas and Pertierra 2020) and invertebrates (Lebouvier et al. 2011;Bartlett et al. 2020;Pertierra et al. 2020), or both (Frenot et al. 2005;Duffy et al. 2017;Lee et al. 2017;Duffy and Lee 2019). ...
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Spanning the Southern Ocean high latitudes, Sub-Antarctic islands are protected areas with high conservation values. Despite the remoteness of these islands, non-native species threaten native species and ecosystem function. The most ubiquitous and speciose group of non-native species in the region are invertebrates. Due to their cryptic habits and ambiguous establishment history, the impacts of non-native invertebrates on native species and ecosystems in the region remains largely unknown. Understanding how non-native invertebrate species are transported, disperse, establish and colonise new habitats is key to understanding their existing and future impacts. This research is fundamental to improving biosecurity practise and informing future management of Southern Ocean islands. We undertook invertebrate surveys on Macquarie Island to determine the current status of four non-native macro-invertebrates—Kontikia andersoni and Arthurdendyus vegrandis (Platyhelminthes: Geoplanidae), Styloniscus otakensis (Isopoda: Styloniscidae) and Puhuruhuru patersoni (Amphipoda: Talitridae). Arthurdendyus vergrandis was not intercepted in our surveys, while we found S. otakensis and P. patersoni had not expanded their range. In contrast, K. andersoni has more than doubled its previously mapped area and expanded at a rate of ~ 500 m-yr since 2004. We discuss the possible underlying mechanisms for the dramatic range expansion of K. andersoni and consider the implications for the future management of Macquarie Island.
... Over the past 2 decades, however, the intensity of human activity has continued to increase, driven by not just explorers but also scientific researchers, station support personnel, fishers, whalers, and, more recently, tourists. These increased human activities have a substantial effect on all life forms in Antarctica, transporting nonindigenous species to the continent and exporting endemic and autochthones species to other continents, including human, animal and plant pathogenic fungi (6,7). However, pathogenic fungi are rarely explored in the Antarctic setting (8), and their effect on visitors to Antarctica and on the human populations in other continents is underinvestigated. ...
... Another possibility could be human intervention in the region. Alien microbes, fungi, plants, and animals have arrived over approximately the previous 2 centuries, coinciding with human activity in Antarctica (6). The differentiation of the 7 phylogenetic species in the complex could not be performed with the genetic marker used in this study. ...
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We detected Histoplasma capsulatum in soil and penguin excreta in the Antarctic Peninsula by sequencing after performing species-specific PCR, confirming previous observations that this pathogen occurs more broadly than suspected. This finding highlights the need for surveillance of emerging agents of systemic mycoses and their transmission among regions, animals, and humans in Antarctica.
... Climate change is increasingly impacting the Antarctic Peninsula and improving the success of invasive vegetation species colonizing new areas [41]. Additionally, the increasing temperatures associated with climate change are causing accelerated widespread melting of terrestrial ice, allowing for newly formed ice-free areas for vegetation to colonize [2][3][4]. ...
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There are only two species of native vascular plants found on the Antarctic Peninsula and the surrounding islands, Deschampsia Antarctica, and Colobanthus quitensis. Poa annua, a successful invasive species, poses a threat to D. antarctica and C. quitensis. This region may experience extreme changes in biodiversity due to climate change over the next 100 years. This study explores the relationship between vascular vegetation and changing temperature on the Antarctic Peninsula and uses a systems modelling approach to account for three climate change scenarios over a 100-year period. The results of this study indicate that (1) D. antarctica, C. quitensis, and P. annua will likely be impacted by temperature increases, and greater temperature increases will facilitate more rapid species expansion, (2) in all scenarios D. antarctica species occurrences increase to higher values compared to C. quitensis and P. annua, suggesting that D. antarctica populations may be more successful at expanding into newly forming ice-free areas, (3) C. quitensis may be more vulnerable to the spread of P. annua than D. antarctica if less extreme warming occurs, and (4) C. quitensis relative growth rate is capable of reaching higher values than D. antarctica and P. annua, but only under extreme warming conditions.
... Of these, 6 were decapods that were recorded to have established communities; the Red King Crab (Paralithodes camtschaticus), Chinese Mitten Crab (Eriocheir sinensis), European Brown Shrimp (Crangon crangon), Snow Crab (Chionoecetes opilio), and the Atlantic Rock Crab (Cancer irroratus) (Chan et al, 2018). In contrast, while there have been a considerable number of studies carried out on the likelihood of invasions in the region, there has been no concrete record of invasive decapod species in the Antarctic ocean specifically, to date (Frenot et al, 2005;McCarthy et al, 2019;McCarthy et al, 2022;Bastos and Junqueira, 2010). The lack of any official records may boil down to semantics as the terms "alien" and "invasive" has been used interchangeably in many studies. ...
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Over recent decades, polar waters have experienced an unprecedented amount of anthropogenic activity due to climate change melting sea-ice and creating new pathways through previously inaccessible waters. As anthropogenic activity increased in these regions, shipping has become more frequent and thus the movement of organisms through ballast water and hull fouling has also increased. As such, polar waters have become particularly susceptible to bio-invasions. Notably, decapod bio-invasions in both the Arctic and the Antarctic have been rising due to increased transoceanic movement through polar waters as well as the overall warming of polar waters. This is particularly interesting as decapods face a range of biogeographical and physiological barriers (such as below freezing temperatures and high magnesium [Mg 2+ ] concentrations) that limits successful introductions, establishment, and geographic spread. Available literature suggests that as climate change drives disproportionate warming of polar waters, geographic and physiological barriers are being broken down both directly and indirectly via anthropogenic activity thus driving an increase in observed decapod invasions. This review assessed decapod bio-invasions in both the Arctic and the Antarctic with regard to key vectors of invasion, and physiological determinants to create an overview of decapod invasions in polar waters as whole as well as to create a preliminary list of invasive decapod species in polar waters.
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European starlings (Sturnus vulgaris) were introduced ca. 40 years ago to South America, where they naturalized to central and northern Argentina, now reaching some neighboring countries. While Patagonia (southern Argentina and Chile) has remained free of European starlings (ES) in the past, they are now present along its northern boundary. Our objectives were to 1) investigate the factors explaining this recent invasion, and 2) predict how starlings might expand across southernmost America based on niche modeling using landform, land cover, and climatic variables representing conditions that may limit ES. Based on records from community science, informants, and our own observations, we conclude that two parallel processes generated new population nodes in northern Patagonia: 1) a southwards expansion from their core areas near the Atlantic coast (generating an incipient population node in NE Patagonia), and 2) birds released or escaped from captivity (generating an isolated population node in north-central Patagonia). Community science data was most useful from 2018 onwards, while data from informants was key to understand previous events (e.g., first ES confiscated from illegal trade in 2008; first free ranging ES seen in 2014). The most parsimonious model confirmed our prediction that human transformed lands in several portions within the target area are suitable for ES establishment, both in Chile and Argentina. Null suitability was modeled for the lands in southernmost Patagonia (all cover types). Desert lands (Patagonian steppe, Monte Desert, High Andes) that skirt the Andean temperate forests on the north, and most of the Andean forests, turned out to be unsuitable (especially with increasing latitude). Conversely, most of coastal Argentine Patagonia and the human-transformed lands of south-central Chile emerged as moderately suitable habitat for ES. Because the riverine areas under current ES colonization in northern Patagonia are fovorable for ES (i.e., agricultural and urban lands with abundant nesting sites), without control actions, this species might soon spread over ca. 5,000 km2 around the Colorado and Negro rivers, affecting their agricultural industry. These rivers, which run west-east through desert lands unsuitable for ES, now represent corridors into south-Andean ecosystems, as they are surrounded by treed land (willows and poplars introduced from Europe) not originally available, connecting formerly separate ecoregions. In case ES manage to reach the eastern slopes of the Andes, they might cross to Chile through low elevation passes (<1000 masl) available south of ca. 38°S. The valleys of south-central Chile are both suitable habitat for ES and valuable productive lands that may be threatened by the invasion. We present management suggestions, and advocate for the development of a bi-national strategy to retard, prevent and alleviate the far-reaching impacts ES may exert on America’s southernmost ecosystems and resources.
Chapter
Terrestrial environments of Antarctica include some of the most extreme on Earth, challenging the very existence of life itself. This article outlines briefly the geological and biological history of the continent, leading on to the conditions currently experienced, before describing its terrestrial biogeography and biota. Major determinants of terrestrial biodiversity and ecosystem function are discussed and consideration given to natural and human-induced processes of ecosystem development and change.
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We report the first formal record of the Indian meal moth Plodia interpunctella from a location within the Antarctic Treaty area, with the capture of a live adult male within the Brazilian Comandante Ferraz research station on King George Island, South Shetland Islands. This species is a well-known pest of stored products and is widely recorded in synanthropic situations such as food stores globally. No other adults or immature stages have been observed on the station. While there is no suggestion that P. interpunctella could survive or establish in the natural environment beyond the station, this observation highlights the ever-present threat of unintended anthropogenically assisted transfer of non-Antarctic species into human facilities on the continent, with some such species proving extremely difficult to eradicate if they successfully establish within these facilities.
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Sub-Antarctic fjords are among the environments most affected by the recent climate change. In our dynamically changing world, it is essential to monitor changes in these vulnerable settings. Here, we present a baseline study of “living” (rose Bengal stained) benthic foraminifera from fjords of South Georgia, including fjords with and without tidewater glaciers. Their distribution is analyzed in the light of new fjord water and sediment property data, including grain size and sorting, total organic carbon, total sulfur, and δ13C of bulk organic matter. Four well-defined foraminiferal assemblages are recognized. Miliammina earlandi dominates in the most restricted, near-shore and glacier-proximal habitats, Cassidulinoides aff. parkerianus in mid-fjord areas, and Globocassidulina aff. rossensis and Reophax subfusiformis in the outer parts of fjords. Miliammina earlandi can tolerate strong glacial influence, including high sedimentation rates in fjord heads and sediment anoxia, as inferred from sediment color and total organic carbon/sulfur ratios. This versatile species thrives both in the food-poor inner reaches of fjords that receive mainly refractory petrogenic organic matter from glacial meltwater, and in shallow-water coves where it benefits from an abundant supply of fresh, terrestrial and marine organic matter. A smooth-walled variant of C. aff. parkerianus, apparently endemic to South Georgia, is the calcareous rotaliid best adapted to inner fjord conditions characterized by moderate glacial influence and sedimentation rates and showing no preference for particular sedimentary redox conditions. The outer parts of fjords with clear, slightly warmer bottom water, are inhabited by G. aff. rossensis. Reophax subfusiformis dominates in the deepest-water settings with water salinities ≥ 33.9 PSU and temperatures 0.2–1.4 °C, characteristic for Winter Water and Upper Circumpolar Deep Water. The inner- and mid-fjord foraminiferal assemblages seem specific to South Georgia, although with continued warming and deglaciation they may become more widespread in the Southern Ocean.
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Bryophyte colonists develop from sexual and asexual propagules deposited over a long period from both local and distant provenances. Some may rapidly establish new plants; others remain dormant indefinitely on or beneath the surface of the substratum. The viable component of these diaspores, the soil propagule bank, constitutes a reservoir of potential colonists. An environmental stimulus or suite of stimuli may activate the dormant viable propagules into developing as new plants. Before this, microbial modification of the soil surface is usually required to bind and stabilize soil particles and provide a nutrient base. Laboratory and field experiments on maritime Antarctic soils are used to illustrate aspects of the bryophyte propagule bank. The importance of ice fields as a sink for spores and vegetative propagules is stressed. Their release in meltwater onto terrestrial habitats near the ice margins is of particular importance in colonziation of newly exposed substrata. Possible efects of global warming, especially in polar regions, on these propagule banks, on the rate of colonization and on the species composition of the developing communities is considered. -from Author
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The sub-Antarctic islands have been subjected to man's influence for about 200yr, yet in that time many have been greatly affected by introduced species. The key factor influencing the success of a region for the establishment of introduced species is whether it affords a year-round supply of food. For herbivores this implies the existence of plants, and such animals are therefore indirectly as well as directly affected by temperature and other climatic features. The distributions, histories of introduction, ecology and environmental impacts are described for: rats Rattus norvegicus and R. rattus, house mouse Mus musculus, rabbit Oryctolagus cuniculus, reindeer Rangifer tarandus and car Felis catus. Implications for conservation are noted.-P.J.Jarvis
Chapter
A small Plutella xylostella L. (Lepidoptera: Plutellidae) population was discovered in 1986 on Marion Island where larval feeding causes considerable damage to the native crucifer Pringlea antiscorbutica R. Br. Between April 1986 and May 1988 the population was monitored, on an opportunistic basis, to establish its dynamics, local distribution and the interaction of P. xylostella with its host. The first signs of larval infestation were detected at the start of the austral summer (December), after which the larval population rapidly built up to maximum density during April/May. After the onset of winter (July) the population crashed, with no sign of infestation during the remainder of winter and spring. In the laboratory on Marion Island, generation turnover times were similar to those recorded in temperate areas. The few taxa of the native biota allow ample opportunity for successful colonization by introduced species. The selective advantages that enabled the introduction and successful establishment of P. xylostella on Marion Island include cold tolerance and such r-selected traits as migratory ability, high fecundity, and rapid growth and generation turnover. P. xylostella should be regarded as a well-adapted colonizer on Marion Island, and the opportunities for population genetic research, presented by this founder event, should be used to advantage.