Impact of anthropogenic transportation to Antarctica on alien seed viability

Abstract

Antarctic ecosystems are at risk from the introduction of invasive species. The first step in the process of invasion is the transportation of alien species to Antarctic in a viable state. However, the effect of longdistance human-mediated dispersal, over different timescales, on propagule viability is not well known. We assessed the viability of Poa trivialis seeds transported to Antarctica from the UK, South Africa and Australia by ship or by ship and aircraft. Following transportation to the Antarctic Treaty area, no reduction in seed viability was found, despite journey times lasting up to 284 days and seeds experiencing temperatures as low as -1.5°C. This work confirms that human-mediated transport may overcome the dispersal barrier for some propagules, and highlights the need for effective pre-departure biosecurity measures.

Continent-wide risk assessment for the establishment of nonindigenous species in Antarctica

“…Sampling was considered to capture the large majority of seeds, although this somewhat underestimated propagule pressure (21). The number of seeds that would drop off a visitor was considered proportional to the number of seeds found during sampling, and propagule viability was considered high (41,46).…”

Alien invertebrates transported accidentally to the Polish Antarctic Station in cargo and on fresh foods

“…This condition may also promote survival of a wide spectrum of associated organisms. The rest of the cargo (in average 30 tons per year), ex− cluding frozen items, were kept in the ships hold, where conditions may also allow the survive of many species (Hughes et al 2010b). This study has clearly demon− strated that a lot of cargo items can act as potential vectors for alien organisms.…”

“…Through cargo and expeditioners a wide range of alien organisms or their propagules can be transported unintentionally and introduced ultimately to the Antarctic from distinct habitats all over Earth (Whinman et al 2005;Hughes et al 2010b). Ships and planes can transport alien species between locations relatively rapidly.…”

“…This helps organisms retain viability during transit (Hughes et al 2010a). More than one hundred year−round or summer only stations, refuges and field camps are re−supplied annually or several times each year (Chwedorzewska 2009;Hughes et al 2010b, Hughes and Convey 2010. Arctowski Station main cargo is usually supplied once a year, but a couple of times during the summer sea− son they are re−supplied by ships with small amounts of fresh products from South America.…”

“…In recent decades the transport distribution barrier around Antarctica has been circumvented by a rapid increase in human ac− tivity in this region (Lee and Chown 2009a, b;Hughes et al 2010b). Globalization and increasing human movements are particularly apparent in the Antarctic.…”