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The increasing rate of incidents involving vessels in the Southern Ocean (including vessels sinking) has highlighted the potential for substantial fuel spills into the Antarctic environment. An increasing number of tourist and fishing vessels, often without ice strengthened hulls, are penetrating farther into, and staying longer in, Antarctic waters, with a focus for destinations of wildlife concentrations. Based on a survey of national operators in the Antarctic, there is little preparation for an oil spill event that involves Antarctic wildlife. This is a recipe for a catastrophic spill event, with the potential for high numbers of oiled wildlife in a remote part of the world where there are major logistical constraints on the provision of equipment and skilled response personnel. Here we chronicle shipping incidents that have led to oil spills in the Southern Ocean, the current legislation and contingency plans currently in place by national Antarctic operators, and examine their preparedness and expertise for an oiled wildlife event response. It is clear that national, fishing and tourism operators are manifestly unprepared for an oiled wildlife event in the Southern Ocean. We identify five critical constraints to any response and provide recommendations that address these constraints. [ABSTRACT FROM PUBLISHER]

Before 1998, concern was raised over the potential for human activities in Antarctica to introduce infectious disease organisms to native wildlife. A workshop was held that year to address this issue. In the last decade, there has been a dramatic increase in human traffic to the Antarctic and the number of commercial tourists visiting the Antarctic has steadily risen. Personnel of national science programmes, though relatively few in numbers, have the most intimate contact with wildlife and thus the greater potential to introduce organisms through their research activities. Many visitors are now able to arrive in the Antarctic from temperate regions within hours by aircraft, and from northern polar regions within 24 to 36 hours. Tourists, by their high numbers, also have the potential to transfer infectious disease agents among commonly visited sites. As of 2009, no outbreaks of infectious diseases in the Antarctic reported in the literature have been directly attributed to human activity, but the ameliorating climate may break down the barriers that have kept Antarctic wildlife relatively free of infectious diseases. Several agents of infectious diseases reported in Antarctic seabirds and seals are assessed for their likelihood to occur more frequently in terms of the characteristics of the agent, the behaviour of Antarctic wildlife, and the effects of an ameliorating climate (regional warming) in conjunction with continued increasing human activities. [ABSTRACT FROM PUBLISHER]

Investigations in recent years of the ecological structure and processes of the Southern Ocean have almost exclusively taken a bottom-up, forcing-by-physical-processes approach relating various species' population trends to climate change. Just 20 years ago, however, researchers focused on a broader set of hypotheses, in part formed around a paradigm positing interspecific interactions as central to structuring the ecosystem (forcing by biotic processes, top-down), and particularly on a "krill surplus" caused by the removal from the system of more than a million baleen whales. Since then, this latter idea has disappeared from favour with little debate. Moreover, it recently has been shown that concurrent with whaling there was a massive depletion of finfish in the Southern Ocean, a finding also ignored in deference to climate related explanations of ecosystem change. We present two examples from the literature, one involving gelatinous organisms and the other involving penguins, in which climate has been used to explain species' population trends but which could better be explained by including species interactions in the modelling. We conclude by questioning the almost complete shift in paradigms that has occurred and discuss whether it is leading Southern Ocean marine ecological science in an instructive direction. [ABSTRACT FROM AUTHOR]

Conservation of the high seas marine environment poses a significant challenge to policy-makers and managers. Marine conservation efforts are often hindered by the lack of data and the difficulties in addressing multiple, and typically conflicting uses. The majority of extant Marine Protected Areas (MPAs) are in coastal or tropical regions within national jurisdiction. Conservation of high seas MPAs has emerged on the international agenda as a critical issue requiring the application of novel approaches, international cooperation and political will. Knowledge and understanding of the marine environment and data on marine biodiversity are all typically limited for the high seas, and the use of surrogates to assist in the identification of areas of high conservation value is one possible mechanism to address and potentially overcome these limitations. Drawing upon a database spanning more than 20 years and containing approximately 140 000 records of seabird sightings at sea, this study assesses the potential use of seabirds as surrogates for marine biodiversity in the Indian sector of the Southern Ocean. At-sea ranges, species diversity and the distributions of endangered species may be appropriate selectors or filters to identify areas with high conservation values. Integrating policy with science provides an appropriate mechanism to identify and prioritise MPAs in the Southern Ocean. [ABSTRACT FROM AUTHOR]

We investigated 17 abandoned Adélie penguin (Pygoscelis adeliae) colonies in the Windmill Islands, East Antarctica, in summer 2002/03. Forty radiocarbon dates on penguin bones and eggshells from 13 of these sites indicate a near continuous occupation by breeding penguins in this region for over 9000 years. These dates refine the recent geological record in this region and indicate that deglaciation of the northern islands occurred much earlier than previously suggested. Dietary remains from these sites include at least 23 taxa of cephalopods and teleost fish. Quantification of these remains indicates significant fluctuations in the relative abundance of two of the more common major prey taxa. The Antarctic silverfish (Pleuragramma antarcticum Boulenger) was the most common teleost prey during all time periods represented by the ages of the sites, but preservational factors may explain a gradual decrease in the remains of this species in increasingly older sites. The most common cephalopod in the sediments was the squid, Psychroteuthis glacialis Thiele, which occurred in low numbers in most sites except one (Site 75). An unusually high number of squid beaks preserved in Site 75, dating to approximately 5700-6100 cal. yr BP, does not correlate with a decrease in fish prey at that time. The high number of abandoned penguin colonies (> 200) in the Windmill Islands may be due to population cycles in the past in association with low nest-site fidelity and movement by breeding penguins to new sites within this region. [ABSTRACT FROM AUTHOR]

The selection of sites that comprise the existing network of Antarctic protected areas has been largely ad hoc, driven by national interests rather than concerted efforts to ensure systematic and representative coverage of the Antarctic environment. Consequently there are gaps in coverage of all major ecosystems, in particular areas kept inviolate from human activity, inland lakes, and marine protected areas. Annex V of the 1991 Protocol on Environmental Protection to the Antarctic Treaty provides a list of values to be protected within a network of Antarctic Specially Protected Areas (ASPAs), but provides no quantitative methods for site identification and prioritisation. The Antarctic Important Bird Area (IBA) Inventory is a joint initiative of BirdLife International and the Scientific Committee on Antarctic Research Group of Experts on Birds (formerly the Bird Biology Subcommittee). The Antarctic IBA Inventory has identified 119 candidate IBAs, 97 of which are not currently protected as ASPAs. The IBA Inventory can improve the Antarctic Protected Area System (PAS) in that it provides a method by which to identify and prioritise sites for their potential inclusion in the Antarctic PAS. [ABSTRACT FROM AUTHOR]

The relationship between colony area and population density of Adelie penguins Pygoscelis adeliae was examined to determine whether colony area, measured from aerial or satellite imagery, could be used to estimate population density, and hence detect changes in populations over time. Using maps drawn from vertical aerial photographs of Adeliepenguin colonies in the Mawson region, pair density ranged between 0.1 and 3.1 pairs m-2, with a mean of 0.63 t 0.3 pairs m-2. Colony area explained 96.4% of the variance in colony populations (range 90.4-99.6%) for 979 colonies at Mawson. Mean densities were not significantly different among the 19 islands in the region, but significant differences in mean pair density were observed among colonies in Mawson, Whitney Point (Casey, East Antarctica) and CapeCrozier (Ross Sea) populations. The relationship between colony areaand population may be locality- and/or species-specific, and a robust data set is required to validate the relationship. [ABSTRACT FROM AUTHOR]

Elucidating the factors underlying the origin and maintenance of genetic variation among populations is crucial for our understanding of their ecology and evolution, and also to help identify conservation priorities. While intrinsic movement has been hypothesized as the major determinant of population genetic structuring in abundant vagile species, growing evidence indicates that vagility does not always predict genetic differentiation. However, identifying the determinants of genetic structuring can be challenging, and these are largely unknown for most vagile species. Although, in principle, levels of gene flow can be inferred from neutral allele frequency divergence among populations, underlying assumptions may be unrealistic. Moreover, molecular studies have suggested that contemporary gene flow has often not overridden historical influences on population genetic structure, which indicates potential inadequacies of any interpretations that fail to consider the influence of history in shaping that structure. This exhaustive review of the theoretical and empirical literature investigates the determinants of population genetic differentiation using seabirds as a model system for vagile taxa. Seabirds provide a tractable group within which to identify the determinants of genetic differentiation, given their widespread distribution in marine habitats and an abundance of ecological and genetic studies conducted on this group. Herein we evaluate mitochondrial DNA (mtDNA) variation in 73 seabird species. Lack of mutation-drift equilibrium observed in 19% of species coincided with lower estimates of genetic differentiation, suggesting that dynamic demographic histories can often lead to erroneous interpretations of contemporary gene flow, even in vagile species. Presence of land across the species sampling range, or sampling of breeding colonies representing ice-free Pleistocene refuge zones, appear to be associated with genetic differentiation in Tropical and Southern Temperate species, respectively, indicating that long-term barriers and persistence of populations are important for their genetic structuring. Conversely, biotic factors commonly considered to influence population genetic structure, such as spatial segregation during foraging, were inconsistently associated with population genetic differentiation. In light of these results, we recommend that genetic studies should consider potential historical events when identifying determinants of genetic differentiation among populations to avoid overestimating the role of contemporary factors, even for highly vagile taxa., (© 2020 Cambridge Philosophical Society.)