The biogeography of the South Indian Ocean Province (SIP) biotas has long been controversial. Much of the discussion has been based on interpretation of species distributions, based on morphological or anatomical delimitations. However, molecular phylogenetic approaches elsewhere have recently shown that interpretations based solely on morphological data may be misleading. Nonetheless, few studies have employed molecular phylogenetic approaches to understand the biogeography of the SIP biotas. We do so here for the Ectemnorhinus group of genera, a monophyletic unit of weevils endemic to the region. We use mitochondrial cytochrome oxidase I DNA sequence data to reconstruct relationships among 13 species and 22 populations in the genera Palirhoeus, Bothrometopus and Ectemnorhinus. On the basis of this analysis we find little support for separating the genus Palirhoeus from Bothrometopus, and little support for the morphologically-based species groups currently recognized within Bothrometopus. Using a molecular clock we show that dispersal among islands probably took place against the prevailing wind direction. These data also support a previous hypothesis of radiation of the epilithic genera Bothrometopus and Palirhoeus during the Pliocene/early Pleistocene, but reject the hypothesis that the genus Ectemnorhinus radiated following the last glacial maximum. We show that Bothrometopus parvulus (C.O. Waterhouse) on the Prince Edward Islands comprises two species that are not sister taxa. We name the second species Bothrometopus huntleyi n. sp. and provide a description thereof.

Gut contents studies have shown that Notothenia coriiceps, a prevalent shallow water fish species along the western Antarctic Peninsula, has a highly variable diet. This variability, coupled with small home ranges, suggest that microhabitat may play a role in determining the chief prey items of N. coriiceps. We trapped fish from three sites comprised of two different algal microhabitats around Palmer Station, Antarctica and investigated their diets via gut contents and stable isotope analyses. Gut contents analysis revealed that amphipods were the primary prey item at all three sites, but the distribution of amphipod species eaten varied between sites. Other important prey classes were snails, limpets, algae and fish. Overall, the gut content data suggested that algal microhabitat was less important than geographic location in determining diet. On the other hand, stable isotope analysis indicated that fish from the Palmaria decipiens site were more enriched in both carbon and nitrogen than fish from Desmarestia menziesii sites. Hence, it would appear that in the longer term, algal microhabitat may influence fish diets and trophic relationships.

Changes in adult weight, lipid and fatty acid composition per lipid class were studied over a complete seasonal cycle in Drepanopus pectinatus Brady. This copepod displayed a strong seasonality in adult individual weight and total lipid content. Stages C3 to adult from a summer cohort were compared in terms of lipid and fatty acid structure. Changes in lipid content were related to wax esters and polar lipids (PL) while triacylglycerols (TAG) and cholesterol remained minor constituents except at the end of winter. Changes in fatty acid composition of different lipid classes showed that food limitation in winter was high enough to affect 22:6n-3 (DHA) content in PL, and provoke accumulation of maximal percentages of bacterial marker as branched acids. Composition of TAG followed closely the changes in trophic interactions as diatom and flagellate markers dominated in spring and summer while bacterial and detritus particle markers dominated in late winter. The composition of wax esters followed the same seasonal succession but with a lower level of turn over time and shifted characteristics (bacterial markers) from winter to spring individuals when compared to TAG. Ontogenetic changes showed high triacylglycerols content in younger C3 stages and increasing wax esters with increasing developmental stages. Fatty acid composition of PL showed low percentages of EPA and DHA in stage C3, and recovery of high levels of DHA for stage C4 or 20:5n-3 (EPA) at stage C5. The same trend was observed for 18:4n-3. The reverse pattern was noted for the n-6 polyunsaturated acids (PUFA) suggesting a greater requirement in younger stages. Fatty acid partitioning between neutral and PL suggested essential fatty acids selective incorporation from neutral classes into membrane lipids.

Palmaria decipiens (Reinsch) R.W. Ricker (1987) represents one of the dominant rhodophyte species in Antarctic coastal ecosystems. Due to its high abundance in the intertidal and upper subtidal it plays a key role in ecosystem structure and function, providing habitat, food and shelter for a multitude of associated organisms. The physiology, reproductive strategy and life cycle of P. decipiens is considered as being well adapted to the Antarctic environment, which is characterized by permanent low water temperatures and a strong seasonality in light climate. With its obvious ecological significance and adaptive strategies P. decipiens was frequently studied as a typical representative of an endemic Antarctic macroalga. Here we provide an overview of the recent literature, summarizing the knowledge gained about the alga during the last 25 years. This review focuses on the species life cycle and physiological responses, such as temperature requirements, photosynthetic characteristics, pigment content and protective mechanisms with regard to enhanced ultraviolet radiation (UV-B radiation, 280–315 nm and UV-A radiation, 315–400 nm). The ecology of P. decipiens is reviewed focussing on grazing activity and abundance patterns. Since most studies on P. decipiens have been conducted at King George Island off the western Antarctic Peninsula this overview serves as a summary of baseline data from an ecosystem particularly prone to environmental change.

The multilateral failure to apply the Convention on Biological Diversity (CBD) by the target year 2010 was headline news as are the accelerating climatic changes which dictate its urgency. Some ecosystems that are vulnerable to anthropogenic change have few species listed as endangered because too little is known about their biota. The highest vulnerability may correspond to where hotspots of species endemism, range limits and physiological sensitivity overlap with areas of most rapid physical change. The old, large and remote archipelago of South Georgia is one such location. Sea-surface temperatures around South Georgia are amongst the most rapidly warming reported. Furthermore oceanographic projections are highlighting the region as extremely vulnerable to ocean acidification. We outline the first polar Darwin Initiative project and the technical advances in generating an interactive and fully integrated georeferenced map of marine biodiversity, seabed topography and physical oceanography at South Georgia. Mapping marine mega and macro-faunal biodiversity onto multiple physical variables has rarely been attempted. This should provide a new tool in assessing the processes driving biological variability, the importance of marine areas in terms of ecosystem services, the threats and vulnerabilities of Polar Regions and should greatly aid implementation of the CBD.

As baleen whales recover from severe exploitation, they are probably subject to a wide variety of threats within the Antarctic marine ecosystem, including directed take. Here we review both the management and current status of Antarctic baleen whales and consider those threats likely to impact on them. Threats range from global problems - marine pollution and climate change - to localized issues including shipping, habitat disturbance, unregulated wildlife tourism and fishery activities. We identify the most pressing anthropogenic threats to baleen whales including scientific whaling and climate change. It is unclear whether current management approaches will be able to effectively encompass all these threats while also accounting both for the differing levels of scientific understanding and for the differing recovery rates of the whale species. For management we recommend the following: 1) incorporation of both ecosystem considerations and the suite of identified threats not limited to direct take, 2) identification of measurable indicators of changes in whales that allow more certainty in monitoring of populations and the environment, and 3) recognition of significant relationships between baleen whales and habitat features to provide information on distribution and use.

Ile de la Possession is one of the few islands in the southern Indian Ocean, making the island a valuable place to reconstruct past environmental and climatic changes. In this study a peat sediment core was analysed to reconstruct the changes that occurred before, during and after the eruption of the Morne Rouge (10 000–5500 14C yr bp) volcano. In addition to sedimentological analyses, diatom communities were used to reconstruct humidity and altitude, based on existing transfer functions. Radiocarbon dating of a tephra layer showed that the Morne Rouge volcano erupted between 6700–6600 cal. yr bp, giving a much more precise time scale for this event. The eruption was preceded by a tsunami flooding, indicated by the high numbers of marine diatoms found immediately before the tephra layer. After the eruption pioneer diatom species recolonized the coring site. Evidence is presented of the late climatic optimum around 3050 cal. yr bp, preceded by a cooling event until 6600 cal. yr bp. Nutrient input from elephant seals and wandering albatrosses obscured the climate signal for the last 600 cal yr bp.

Until recently, the spectacled petrel Procellaria conspicillata Gould was listed as Critically Endangered due to its small population size and ongoing incidental mortality on fishing gear. Surveys at its sole breeding locality, Inaccessible Island in the central South Atlantic Ocean, indicated that the population increased from 1999–2004, resulting in the species being down-listed to Vulnerable. We repeated the census of breeding spectacled petrels during the early incubation period in October–November 2009. Numbers of burrows increased by 55% from 2004–09, with increases in all count zones, and the greatest changes in peripheral populations. Burrow occupancy estimates remained high, averaging 81% during one-off checks. Our best estimate of the population in 2009 was 14 400 pairs, continuing the c. 7% per year increase inferred since the 1930s following the disappearance of introduced pigs. This confirms the rapid recovery of this species despite ongoing mortality on fishing gear. Our results suggest that at least some procellariiforms are able to sustain strong growth rates in the face of fishing mortality when colony based threats are removed.

Nineteen specimens of the rare dragonfish Vomeridens infuscipinnis were evaluated for meristic counts, morphometric measurements, vomerine teeth and the supratemporal canal, anatomical and histological observations of bone, cartilage and lipid, diet, and reproductive status. Seven individuals were measured for buoyancy. All specimens had small vomerine teeth that varied in number. There was also variability in the arrangement of the supratemporal pores and canals. Vomeridens possess a body with little bone and considerable amounts of cartilage and lipid. A mean percentage buoyancy of 1.61% indicated that Vomeridens is nearly neutrally buoyant. Inferences from measurements of buoyancy and from morphological data suggest that Vomeridens lives in an epibenthic water column habitat at 400–900 m. Facilitated by its reduced body density, Vomeridens are likely to forage in the water column by hovering above the substrate. The stomach contents consisted of krill (Euphausia superba), some as large as 46–50 mm.The absolute and relative fecundity in seven female was 1576–2296 oocytes (mean 1889) and 21.3–28.9 oocytes g-1 body weight (mean 25.3), respectively. The reproductive effort in terms of egg diameter, GSI, and absolute and relative fecundity is similar to that for other bathydraconids.

For land-breeding marine organisms such as seabirds, knowledge about their habitat use has mainly been gained through studies of breeding individuals that are constrained to return frequently to their breeding grounds. In this study we set out to measure whether: a) habitat selection in the non-breeding period predicts habitat selection in the breeding period, and b) whether breeding individuals concentrated their activity on the closest suitable habitats. Macaroni Eudyptes chrysolophus and gentoo Pygoscelis papua penguins, two marine predators with contrasting foraging strategies, were tracked from the Iles Kerguelen and their habitat selection investigated through Mahalanobis distances factorial analysis. This study presents the first data about gentoo penguins’ juvenile dispersal. For both species, results showed 6.9 times larger maximum ranges and up to 12.2 times greater distances travelled during the non-breeding period. Habitat suitability maps suggested both species made similar environmental selections whatever the period. Macaroni penguins targeted pelagic areas beyond the shelf break while gentoo penguins always remained over the shelf. We consider the ecological significance of larger scale movements made outside the breeding period and suggest that this non-breeding period is of particular interest when attempting to understand an animal's habitat selection.

Archaea, once thought to be only extremophiles, are now known to be abundant in most environments. They can predominate in microbial communities and be significantly involved in many global biogeochemical cycles. However, Archaea have not been reported in Antarctic sea ice. Our understanding of the ecology of Antarctic sea ice prokaryotes is still in its infancy but this information is important if we are to understand their diversity, adaptations and biogeochemical roles in Antarctic systems. We detected Archaea in sea ice at two sampling sites taken from three subsequent years using conserved 16S rRNA gene archaeal primers and PCR. Archaeal abundance was measured using quantitative PCR and community diversity was investigated by sequencing cloned 16S rRNA gene PCR products. Archaea in Antarctic sea ice were found to be in low abundance consisting of ≤ 6.6% of the prokaryotic community. The majority, 90.8% of the sequences, clustered with the recently described phylum Thaumarchaeota, one group closely clustered with the ammonia-oxidizing Candidatus Nitrosopumilus maritimus. The remainder of the clones grouped with the Euryarchaeota.

Bothrometopus huntleyi is a flightless weevil endemic to the volcanically-formed sub-Antarctic Prince Edward Islands archipelago that arose approximately 0.5 million years ago (m.y.a.). Since emergence, a series of volcanic and glaciation events have occurred on Marion Island, whilst Prince Edward Island, the second island constituting the archipelago, has remained largely unaffected by glaciation. Cytochrome oxidase I gene analyses indicate that major historical dispersal events in this species are linked to the geologically discrete histories of these islands and underlie the high haplotype diversity (0.995) recovered for the Prince Edward Islands archipelago. The estimated time to haplotype coalescence of ∼ 0.723 m.y.a. is in keeping with estimated dates of island emergence, and the majority of individuals appear to have descended from a relict, high-altitude population that is still present on Marion Island. The first major inter-island dispersal event occurred ∼ 0.507 m.y.a., coinciding with the oldest dated rocks on Marion Island. Apart from this early inter-island colonization, only one other between-island dispersal event was detected. The genetically discrete B. huntleyi complexes on each of the islands of the Prince Edward Islands archipelago together with the low levels of inter-island gene flow reaffirm the need to control alien invasive mice, which are restricted to Marion Island, and which prey on this weevil species.

Management of non-native species introductions is a conservation priority in the Antarctic region. However, despite the recognised importance of intra-regional propagule transfer, the majority of studies have focused on inter-regional pathways (i.e. from outside of the Antarctic region). Here we quantify the number of seeds carried by expeditioners who have visited sub-Antarctic Marion Island. We recorded 420 seeds from 225 items of clothing, with seeds found on 52% of the items and soil on 45% of them. The median number of seeds for field-based and station-based personnel was 20.5 and 3 per person, respectively. Waterproof trousers and socks, particularly those of field workers, carry the greatest number of propagules (for field workers, medians of 5 and 6.5, respectively) and therefore should be the focus of intra-regional management interventions. Amongst the seeds found entrained within clothing several were from species which are widespread aliens in the Antarctic region including Agrostis stolonifera, Poa annua and Sagina procumbens, and indigenous zoochorous species (Acaena magellanica, Uncinia compacta) were also well represented. The present data provide quantitative evidence in support of previous, largely hypothetical concerns about the risks of intra-regional propagule transfer in the Antarctic.

Recent rapid changes of air temperature on the western side of the Antarctic Peninsula results in increased sediment discharge and ice scouring frequencies in coastal regions. These changes are bound to especially affect slow growing, sessile filter feeders such as the Antarctic bivalve, Laternula elliptica, a long-lived and abundant key species with circumpolar distribution. We investigated the effect of sedimentation and ice scouring on small/young and large/old individuals at two closely located stations, distinctly influenced by both types of disturbance. Small individuals dealt better with disturbance in terms of their respiratory response to sediment exposure, reburrowing ability, and survival after injury, compared to larger animals. At the more disturbed station L. elliptica population density was lower, but larger animals reburrowed faster after iceberg disturbance and reduced their metabolic rate under strong sediment coverage, compared to larger animals of the less disturbed station, indicating that an adaptation or learning response to both types of disturbance may be possible. Smaller individuals were not influenced. Laternula elliptica seems capable of coping with the rapidly changing environmental conditions. Due to a decrease in population density and mean population lifespan, L. elliptica could however lose its key role in the bentho-pelagic carbon flux in areas of high sediment deposition.