Aliens in Antarctica: Assessing transfer of plant propagules by human visitors to reduce invasion risk

Abstract

International audienceDespite considerable research on biological invasions, key areas remain poorly explored, especially ways to reduce unintentional propagule transfer. The Antarctic represents a microcosm of the situation, with the numbers of established non-native species growing. Information to help reduce potential impacts is therefore critical. We measured the propagule load of seeds, and fragments of bryophytes and lichens (the number of other plant or animal fragments was too low to draw any conclusions) carried in the clothing and gear of visitors to the Antarctic, during the 2007/08 austral summer. Samples were collected from different categories of visitors associated with national research programs and tourism and different categories of clothing and gear, new as well as used. We also collected information about the timing of travel and the regions visitors had travelled to prior to Antarctic travel. Seeds were found in 20% and 45% of tourist and science visitor samples, respectively. For bryophyte and lichen fragments the proportions were 11% and 20%, respectively. Footwear, trousers and bags belonging to field scientists were the highest risk items, especially of those personnel which had previously visited protected areas, parklands/botanic gardens or alpine areas. Tourists who visited rural/agricultural areas prior to travel, and/or travel with national programs or on smaller tourist vessels had the highest probability of transferring plant propagules. Travel either during the boreal or austral autumn months increased the probability of propagule presence. Our assessment is applicable to other areas given evidence of propagule transfer patterns in those areas that are broadly similar to those documented here. The current work provides a sound evidence base for both self-regulation (e.g. taking care of personal equipment) and organization-based regulation (e.g. issuing guidelines and holding regular inspections) to reduce propagule transfer of plants to the Antarctic

Past Arctic aliens have passed away, current ones may stay

“…The majority of records of aliens were from currently or formerly inhabited settlements suggesting their introduction was associated with higher levels of human traffic (Chown et al 2012;Huiskes et al 2014;Ware et al 2012); animal husbandry and commerce practices in settlements (Coulson et al 2013(Coulson et al , 2015; and/or generally more favourable local climates. Data permitting the formal testing of the relative roles of these plausible introduction mechanisms are not available.…”

“…), but adopting measures to ensure these activities do not present species invasion risks in the future seems prudent. Adopting a biosecurity framework modelled on existing Antarctic measures would provide more comprehensive protection (Hughes and Convey 2010;Huiskes et al 2014). Such a framework may prove difficult to implement at the panArctic scale, but regional frameworks should be achievable in light of the success experienced in the Antarctic.…”

“…While the awareness of risk of alien species transfer to the Antarctic has resulted in strict international biosecurity measurements (Hughes and Convey 2010;Huiskes et al 2014), no equivalent measurements exist in the Arctic. The independent Arctic countries have each set aside variable areas of land as nature reserves in which the range of permitted activities are limited.…”

Introduction to the special issue on the Life in Antarctica: Boundaries and Gradients in a Changing Environment (XIth SCAR Biology Symposium)

“…Increased activity of tourist operators in some places of the maritime Antarctic is also another matter of concern. Disturbance by trampling of the fragile moss and lichen communities has been monitored (Pertierra et al 2013), and protocols to avoid contamination and transfer of plant propagules by humans have been developed (Huiskes et al 2014).…”

Biological invasions in terrestrial Antarctica: what is the current status and can we respond?

“…However, no terrestrial species introduced to the Antarctic continent intentionally (mainly for scientific research reasons) have been formally identified as invasive (Smith 1996), but intentional introductions to most subAntarctic islands, before the adoption of legislation prohibiting or controlling this activity, have resulted in substantial impacts (see Convey and Lebouvier 2009). Under current legislative systems, unintentional introductions present the greatest threats to sub-Antarctic and Antarctic ecosystems (Frenot et al 2005), with non-native species potentially being introduced associated with visitors' clothing and personal effects Chown et al 2012b;Huiskes et al 2014), cargo Tsujimoto and Imura 2012), building material (Lee and Chown 2009) and fresh foods .…”