Environmental change and human impacts on terrestrial ecosystems of the sub-Antarctic islands between their discovery and the mid-twentieth century

Abstract

Sub-Antarctic islands share many similarities in their history of human interaction and impacts before the mid-twentieth century. Large impacts on land were associated with the marine exploitation industries of sealing and whaling. Their onshore activities involved consider able construction and pollution in many accessible landing bays, inevitably destroying large areas of coastal terrestrial habitat. Consider able transfer of nutrients to terrestrial environments will have been associated with scavengers utilising large carrion supplies. Attempted establishment of agricultural industries, particularly the introduction of grazing mammals, took place on several islands and, although rarely proving economically viable, often resulted in the long-term creation of feral populations. These were accompanied by introductions of other alien vertebrates, plants and invertebrates to most sub-Antarctic islands, although precise records of introduction events, or subsequent biological studies in this period, largely do not exist. Thus, exploitation industries in this region inevitably led to considerable alterations and impacts to terrestrial ecosystems almost from the outset of human contact with the islands. In the absence of baseline ecological and biodiversity studies, the true magnitude of many of these impacts is difficult to assess, although their legacy continues to the present day. Indeed, the almost complete removal of fur seals may have allowed coastal vegetation to become more extensive and lush than hitherto, paradoxically now regarded as "typical" and threatened by recovery of seal populations.

The significance of the sub-Antarctic Kerguelen Islands for the assessment of the vulnerability of native communities to climate change, alien insect invasions and plant viruses

“…First, the remoteness of the islands limits the influx of populations from the continents. Second, introduction events of alien species have been well documented (for review see Convey and Lebouvier 2009;Frenot et al 2005). Third, the biota on these islands has been subject to long-term monitoring programmes (Chown et al 1998Cooper et al 2009;Convey and Lebouvier 2009;Frenot et al 2001).…”

“…Second, introduction events of alien species have been well documented (for review see Convey and Lebouvier 2009;Frenot et al 2005). Third, the biota on these islands has been subject to long-term monitoring programmes (Chown et al 1998Cooper et al 2009;Convey and Lebouvier 2009;Frenot et al 2001). Sub-Antarctic Islands could therefore potentially facilitate valuable investigations with respect to the patterns of genetic diversity, colonisation pathways and possible postbottleneck genetic diversification.…”

Global Collembola on Deception Island

“…The caldera is open to the sea, because of the horseshoe shape of the island, and so provides sheltered anchorage for vessels. Consequently, the island has been among the most visited regional localities by explorers, sealers, whalers, tourists, and scientists over the last 200 years (Convey and Lebouvier 2009). Norwegian whalers occupied the island during the early part of the Twentieth Century, constructing a shore-based whaling station.…”

Distribution of Barley yellow dwarf virus-PAV in the Sub-Antarctic Kerguelen Islands and Characterization of Two New Luteovirus Species

“…Long distance spread of BYDV through maritime trade between Australia and the USA has previously been proposed on the basis of analysis of herbaria-preserved grasses samples [30]. Although the second most isolated archipelago on earth, the Kerguelen Islands were visited by whalers in the past and regular, if limited, boat traffic has existed for the second part of the 20 th century, if only to provide supplies and food to the limited but permanent human settlement mostly associated with scientific research [31]. In this context, introduction of BYDV on plants or by viruliferous aphids travelling on plant products seems to be the most likely scenario.…”