Antarctic Communities Research Articles

Microbial communities and their potential for degradation of dissolved organic carbon in cryoconite hole environments of Himalaya and Antarctica

Cryoconite holes (cylindrical melt-holes on the glacier surface) are important hydrological and biological systems within glacial environments that support diverse microbial communities and biogeochemical processes. This study describes retrievable heterotrophic microbes in cryoconite hole water from three geographically distinct sites in Antarctica, and a Himalayan glacier, along with their potential to degrade organic compounds found in these environments. Microcosm experiments (22 days) show that 13–60% of the dissolved organic carbon in the water within cryoconite holes is bio-available to resident microbes. Biodegradation tests of organic compounds such as lactate, acetate, formate, propionate and oxalate that are present in cryoconite hole water show that microbes have good potential to metabolize the compounds tested. Substrate utilization tests on Biolog Ecoplate show that microbial communities in the Himalayan samples are able to oxidize a diverse array of organic substrates including carbohydrates, carboxylic acids, amino acids, amines/amides and polymers, while Antarctic communities generally utilized complex polymers. In addition, as determined by the extracellular enzyme activities, majority of the microbes (82%, total of 355) isolated in this study (Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Basidiomycota) had ability to degrade a variety of compounds such as proteins, lipids, carbohydrates, cellulose and lignin that are documented to be present within cryoconite holes. Thus, microbial communities have good potential to metabolize organic compounds found in the cryoconite hole environment, thereby influencing the water chemistry in these holes. Moreover, microbes exported downstream during melting and flushing of cryoconite holes may participate in carbon cycling processes in recipient ecosystems.

Effect of environmental parameters on biodiversity of the fungal component in lithic Antarctic communities

A wide sampling of rocks, colonized by microbial epi-endolithic communities, was performed along an altitudinal gradient from sea level to 3600m asl and sea distance from the coast to 100km inland along the Victoria Land Coast, Antarctica. Seventy-two rock samples of different typology, representative of the entire survey, were selected and studied using denaturing gradient gel electrophoresis to compare variation in fungal diversity according to environmental conditions along this altitudinal and sea distance transect. Lichenized fungi were largely predominant in all the samples studied and the biodiversity was heavily influenced even by minimal local variations. The n-MDS analysis showed that altitude and sea distance affect fungal biodiversity, while sandstone allows the communities to maintain high biodiversity indices. The Pareto-Lorenz curves indicate that all the communities analyzed are highly adapted to extreme conditions but scarcely resilient, so any external perturbation may have irreversible effects on these fragile ecosystems.

Assemblages and habitat preferences of soft bottom Antarctic Amphipoda: Admiralty Bay case study

Amphipoda belong to enormously diverse benthic invertebrate groups in the Southern Ocean, playing a very important role in the Antarctic communities. However, in the majority of ecological studies they are identified only to the order level. Rare ecological studies, where amphipods were identified to the species level, concern mainly shallow sublittoral. There is also poor knowledge about the environmental features that are important in the habitat selection by these crustaceans. The aims of this study were to recognize and describe the soft bottom sublittoral amphipod assemblages of the Antarctic fjord and observe the habitat preferences of dominant species. Additionally, we investigated the usefulness of surrogacy methods in the description of amphipod assemblages. The series of 101 quantitative samples from wide depth range (25–502 m) from Admiralty Bay were studied. The cluster analysis allowed to distinguish four assemblages representing: shallow sublittoral (A), middle sublittoral (B) and deep sublittoral (C) of central basin of the bay and Ezcurra Inlet (D) fauna. The study of habitat preferences led to the recognition of the species whose distribution depended on the depth and type of the sediment. The first group encompassed shallow water species characteristic of assemblage (A). The second set of species was related to the presence of colonial organisms identifying the assemblage (B). Third group of deep water species represented assemblage C, while the group of species preferring fine-grained sediments was found in assemblage D. The surrogacy analysis demonstrated low usefulness of this method in the description of Antarctic amphipod assemblages in non-disturbed areas.

Mechanisms driving Antarctic microbial community responses to ocean acidification: a network modelling approach

Rising atmospheric CO2 concentrations and the subsequent changes to ocean chemistry may have pronounced effects on marine microbial communities, particularly for the cold Southern Ocean. Changes to the microbial community in this region could affect the way nutrients are cycled, impact the efficiency of carbon drawdown, and cause shifts in food supply to higher trophic levels. Increased CO2 could affect the bioavailability of iron to phytoplankton. Fertilisation experiments show that iron can influence phytoplankton community composition, favouring large phytoplankton species in iron-replete conditions. The potential interactive effects of CO2 and iron bioavailability are currently poorly understood but are likely to be important in determining CO2-induced changes to the microbial community. We employ a qualitative network modelling approach to evaluate alternative hypotheses regarding the effects of elevated CO2 on Antarctic microbial communities in incubation experiments. We used a sequential approach to model development and testing, where we first formulated a base model for microbial community interactions, and then sequentially added direct and indirect effects of elevated CO2 on particular groups. We found that model simulations were most consistent with observations from incubation experiments when we assumed an indirect effect of CO2 on phytoplankton. In particular, when we assumed a negative effect of elevated CO2 on the uptake of iron by large phytoplankton, as a result of a decrease in iron bioavailability. Our findings show that qualitative network models can be used to test hypotheses relating to results from experimental studies, and help identify key processes to target in future studies.

Richness and bioactivity of culturable soil fungi from the Fildes Peninsula, Antarctica.

Since the discovery of penicillin, fungi have been an important source of bioactive natural products. However, as a specific resource, the bioactive potentiality and specificity of fungal metabolites from the Antarctic region have had little attention. In this paper, we investigated the diversity patterns and biological activities of cultivable fungi isolated from soil samples in Fildes Peninsula, King George Island, Antarctica. Fungal communities showed low abundance and diversity; a total of 150 cultivable fungi were isolated from eight soil samples. After being dereplicated by morphological characteristics and chemical fingerprints, 47 fungal isolates were identified by ITS-rDNA sequencing. We confirmed that these isolates belonged to at least 11 different genera and clustered into nine groups corresponding to taxonomic orders in the phylogenetic analysis. Using two different fermentation conditions, 94 crude extracts acquired from the abovementioned different metabolite characteristic isolates were screened by bioactivity assay and 18 isolates produced biologically active compounds. Compared with HPLC-DAD-UV fingerprint analysis of culture extracts and standard compounds, two bioactive components secalonic acid and chetracins were identified. Our research suggests that the abundance and diversity of Antarctic cultivable fungal communities exhibit unique ecological characteristics and potential producers of novel natural bioactive products.

Geospatial variability of soil CO2–C exchange in the main terrestrial ecosystems of Keller Peninsula, Maritime Antarctica

Soils and vegetation play an important role in the carbon exchange in Maritime Antarctica but little is known on the spatial variability of carbon processes in Antarctic terrestrial environments. The objective of the current study was to investigate (i) the soil development and (ii) spatial variability of ecosystem respiration (ER), net ecosystem CO2 exchange (NEE), gross primary production (GPP), soil temperature (ST) and soil moisture (SM) under four distinct vegetation types and a bare soil in Keller Peninsula, King George Island, Maritime Antarctica, as follows: site 1: moss-turf community; site 2: moss-carpet community; site 3: phanerogamic antarctic community; site 4: moss-carpet community (predominantly colonized by Sanionia uncinata); site 5: bare soil. Soils were sampled at different layers. A regular 40-point (5×8 m) grid, with a minimum separation distance of 1m, was installed at each site to quantify the spatial variability of carbon exchange, soil moisture and temperature. Vegetation characteristics showed closer relation with soil development across the studied sites. ER reached 2.26μmolCO2m−2s−1 in site 3, where ST was higher (7.53°C). A greater sink effect was revealed in site 4 (net uptake of 1.54μmolCO2m−2s−1) associated with higher SM (0.32m3m−3). Spherical models were fitted to describe all experimental semivariograms. Results indicate that ST and SM are directly related to the spatial variability of CO2 exchange. Heterogeneous vegetation patches showed smaller range values. Overall, poorly drained terrestrial ecosystems act as CO2 sink. Conversely, where ER is more pronounced, they are associated with intense soil carbon mineralization. The formations of new ice-free areas, depending on the local soil drainage condition, have an important effect on CO2 exchange. With increasing ice/snow melting, and resulting widespread waterlogging, increasing CO2 sink in terrestrial ecosystems is expected for Maritime Antarctica.

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

Until recently the Antarctic continent and Peninsula have been little impacted by non-native species, compared to other regions of the Earth. However, reports of species introductions are increasing as awareness of biological invasions as a major conservation threat, within the context of increased human activities and climate change scenarios, has grown within the Antarctic community. Given the recent increase in documented reports, here we provide an up-to-date inventory of known terrestrial non-native species introductions, including those subsequently removed since the 1990s, within the Antarctic Treaty area. This builds on earlier syntheses of records published in the mid-2000s, which focused largely on the sub-Antarctic islands, given the dearth of literature available at that time from the continental and maritime Antarctic regions. Reports of non-native species established in the natural environment (i.e. non-synanthropic) are mainly located within the Antarctic Peninsula region and Scotia Arc, with Deception Island, South Shetland Islands, the most impacted area. Non-native plants have generally been removed from sites of introduction, but no established invertebrates have yet been subject to any eradication attempt, despite a recent increase in reports. Legislation within the Protocol on Environmental Protection to the Antarctic Treaty has not kept pace with environmental best practice, potentially presenting difficulties for the practical aspects of non-native species control and eradication. The success of any eradication attempt may be affected by management practices and the biology of the target species under polar conditions. Practical management action is only likely to succeed with greater co-operation and improved communication and engagement by nations and industries operating in the region.

Ecological niches of Antarctic phototrophic communities during global glaciation

According to paleontological data, large-scale, global glaciations occurred repeatedly over the history of Earth. Such glaciations unavoidably resulted in a sharp decrease in the number of habitats suitable for development of phototrophic microorganisms, which mostly require sunlight. Molecular data indicate that some groups of Antarctic phototrophic microorganisms emerged before formation of the Antarctic ice sheet (30–45 Ma) and probably survived the subsequent glaciation maxima. Analysis of the data on the present-day occurrence of phototrophs in Antarctica revealed the presence of liquid water in a habitat to be the key factor for survival of phototrophic communities. At negative air temperatures, this requirement may be met either in warmer microniches (0 to 30°C and higher) or in brines with freezing temperatures below zero (to −52°C). Development of phototrophic communities in such habitats may indicate the theoretical possibility of existence of the niches favoring growth of phototrophic microorganisms during Precambrian global glaciations. This possibility should be considered in paleontological reconstructions of development of life on Earth.

On the benthic hydroids from the Scotia Arc (Southern Ocean): new insights into their biodiversity, ecology and biogeography

The Scotia Arc, located between the Antarctic Peninsula and the southern tip of South America, is an important zone from the biogeographic point of view. Its benthic biodiversity has been extensively documented with a few exceptions, among others, the hydroid fauna, which constitutes one of the major components of the benthic Antarctic communities. With the aim of increasing the data in three different but complementary fields of knowledge (namely biodiversity, ecology and biogeography), an unpublished collection obtained during the German Antarctic expedition ANTARKTIS XIX/5 (LAMPOS) with the RV Polarstern in 2002 has been studied. A total of 45 species of benthic hydroids, belonging to 9 families and 20 genera, was found. Forty of them, including Halecium stoloniferum sp. nov. and Schizotricha discovery sp. nov., were identified to the species level. Leptothecata was by far the most dominant order with 42 species, while Anthoathecata was only represented by 3 species. Fifteen species (38 %) are endemic to the Antarctic region and 31 (78 %) restricted to Antarctic and/or sub-Antarctic waters. Schizotricha southgeorgiae, Halecium elegantulum and Sertularella argentinica are reported for the second time, whereas Schizotricha jaederholmi, Antarctoscyphus gruzovi and Sertularella jorgensis for the third time. New original autoecological data concerning the use of the substrate, reproductive phenology and bathymetric range of the inventoried species are provided.

A way forward to discover Antarctica's past

Fifty-four participants attended the Antarctic Geologic Drilling Workshop (AGDW) to discuss science objectives and develop key projects. The goal of the NSF-sponsored AGDW was specifically to discuss the interests of US-based scientists in Antarctic and Southern Ocean projects, foster interactions within the Antarctic geoscience community, and discuss top-priority scientific questions and technological requirements to advance outstanding scientific goals. Antarctica, with its thick shroud of glacial ice and fringed belt of floating oceanic ice, offers challenges to unraveling the history of one of Earth’s last frontiers. Rocks deposited in and around Antarctica, reachable through a wide-range of innovative geological drilling approaches, formed during times that witnessed climate and ice-sheet changes. Recovery of rocks through drilling expands the understanding of the interplay of Earth’s dynamic processes that control and respond to the Antarctic cryosphere. Much of our knowledge of past climate changes, and inferred ice-sheet history, has been obtained from drill cores taken in low-latitude settings. Such far-field proxies offer an outline of ice-sheet behavior, but cannot show which part of the ice sheet changed or what the ocean currents, temperatures, or other controlling parameters were in ice-proximal settings. Drilling in Antarctica can yield samples of rock that were influenced directly by glacial processes and which provide access to Antarctica’s ice-covered geology. Limited outcrops, short gravity cores, and drill cores with partial recovery have been studied from many locations, but such records cannot give the continuous temporal record needed to determine the timing and rates of ice-sheet change or boundary conditions controlling that behavior. Spatially distributed records, including transects from onshore to distal records from each major ice drainage basin, are needed to resolve the individual histories of each area. Seismic data linking drill sites can increase the impact of individual sites by extending the details over a broader area and tightening the time constraints at each site. New over-ice seismic data acquisition through systems like Vibroseis will identify new subglacial drilling targets. New methods to sample bedrock and measure conditions beneath the ice will help refine basal-bed boundary conditions that are vital to reconstructions of icesheet behavior. Numerical modeling can test data-driven hypotheses and evaluate forcing mechanisms under different atmospheric boundary conditions. Within the workshop discussions, two general themes rose to highest priority. One is on late Quaternary interglacials, when Earth and ocean conditions were similar to today and ice retreated landward of its current position. The other priority is the study of mid-Cenozoic ice-sheet history during times when boundary conditions of high atmospheric CO2 approached those estimated for the next century, but when Earth and ocean conditions were different from today. Combining records of ice-sheet behavior during these two time intervals and these two sets of conditions that are converging in our future will yield information needed to advance the development of computer simulations for studies of near-term future behavior of Antarctica’s ice sheets. The full report is available at http://agdw.uh.edu/.

A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond

AbstractAntarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone.

Up, down, and all around: scale-dependent spatial variation in rocky-shore communities of Fildes Peninsula, King George Island, Antarctica.

Understanding the variation of biodiversity along environmental gradients and multiple spatial scales is relevant for theoretical and management purposes. Hereby, we analysed the spatial variability in diversity and structure of intertidal and subtidal macrobenthic Antarctic communities along vertical environmental stress gradients and across multiple horizontal spatial scales. Since biotic interactions and local topographic features are likely major factors for coastal assemblages, we tested the hypothesis that fine-scale processes influence the effects of the vertical environmental stress gradients on the macrobenthic diversity and structure. We used nested sampling designs in the intertidal and subtidal habitats, including horizontal spatial scales ranging from few centimetres to 1000s of metres along the rocky shore of Fildes Peninsula, King George Island. In both intertidal and subtidal habitats, univariate and multivariate analyses showed a marked vertical zonation in taxon richness and community structure. These patterns depended on the horizontal spatial scale of observation, as all analyses showed a significant interaction between height (or depth) and the finer spatial scale analysed. Variance and pseudo-variance components supported our prediction for taxon richness, community structure, and the abundance of dominant species such as the filamentous green alga Urospora penicilliformis (intertidal), the herbivore Nacella concinna (intertidal), the large kelp-like Himantothallus grandifolius (subtidal), and the red crustose red alga Lithothamnion spp. (subtidal). We suggest that in coastal ecosystems strongly governed by physical factors, fine-scale processes (e.g. biotic interactions and refugia availability) are still relevant for the structuring and maintenance of the local communities. The spatial patterns found in this study serve as a necessary benchmark to understand the dynamics and adaptation of natural assemblages in response to observed and predicted environmental changes in Antarctica.

Deterrent activities in the crude lipophilic fractions of Antarctic benthic organisms: chemical defences against keystone predators

Generalist predation constitutes a driving force for the evolution of chemical defences. In the Antarctic benthos, asteroids and omnivore amphipods are keystone opportunistic predators. Sessile organisms are therefore expected to develop defensive mechanisms mainly against such consumers. However, the different habits characterizing each predator may promote variable responses in prey. Feeding-deterrence experiments were performed with the circumpolar asteroid macropredator Odontaster validus to evaluate the presence of defences within the apolar lipophilic fraction of Antarctic invertebrates and macroalgae. A total of 51% of the extracts were repellent, yielding a proportion of 17 defended species out of the 31 assessed. These results are compared with a previous study in which the same fractions were offered to the abundant circum-Antarctic amphipod Cheirimedon femoratus . Overall, less deterrence was reported towards asteroids (51%) than against amphipods (80.8%), principally in sponge and algal extracts. Generalist amphipods, which establish casual host–prey sedentary associations with biosubstrata (preferentially sponges and macroalgae), may exert more localized predation pressure than sea stars on certain sessile prey, which would partly explain these results. The nutritional quality of prey may interact with feeding deterrents, whose production is presumed to be metabolically expensive. Although optimal defence theory posits that chemical defences are managed and distributed as to guarantee protection at the lowest cost, we found that only a few organisms localized feeding deterrents towards most exposed and/or valuable body regions. Lipophilic defensive metabolites are broadly produced in Antarctic communities to deter opportunistic predators, although several species combine different defensive traits. Keywords: Antarctic invertebrates; Antarctic algae; chemical ecology; sea star Odontaster validus ; amphipod Cheirimedon femoratus ; chemical defence. (Published: 7 April 2014) Citation: Polar Research 2014, 33 , 21624, http://dx.doi.org/10.3402/polar.v33.21624

Tolerance of polar phytoplankton communities to metals

Large amounts of pollutants reach polar regions, particularly the Arctic, impacting their communities. In this study we analyzed the toxic levels of Hg, Cd and Pb to natural phytoplankton communities of the Arctic and Southern Oceans, and compared their sensitivities with those observed on phytoplankton natural communities from temperate areas. Mercury was the most toxic metal for both Arctic and Antarctic communities, while both Cd and Pb were toxic only for the Antarctic phytoplankton. Total cell abundance of the populations forming the Arctic community increased under high Cd and Pb concentrations, probably due to a decrease of the grazing pressure or the increase of the most resistant species, although analysis of individual cells indicated that cell death was already induced at the highest levels. These results suggest that phytoplankton may have acquired adapting mechanisms to face high levels of Pb and Cd in the Arctic Ocean.

Antarctic DNA moving forward: genomic plasticity and biotechnological potential

Antarctica is the coldest, driest, and windiest continent, where only cold-adapted organisms survive. It has been frequently cited as a pristine place, but it has a highly diverse microbial community that is continually seeded by nonindigenous microorganisms. In addition to the intromission of 'alien' microorganisms, global warming strongly affects microbial Antarctic communities, changing the genes (qualitatively and quantitatively) potentially available for horizontal gene transfer. Several mobile genetic elements have been described in Antarctic bacteria (including plasmids, transposons, integrons, and genomic islands), and the data support that they are actively involved in bacterial evolution in the Antarctic environment. In addition, this environment is a genomic source for the identification of novel molecules, and many investigators have used culture-dependent and culture-independent approaches to identify cold-adapted proteins. Some of them are described in this review. We also describe studies for the design of new recombinant technologies for the production of 'difficult' proteins.

Sponge-associated microbial Antarctic communities exhibiting antimicrobial activity against Burkholderia cepacia complex bacteria

The aerobic heterotrophic bacterial communities isolated from three different Antarctic sponge species were analyzed for their ability to produce antimicrobial compounds active toward Cystic Fibrosis opportunistic pathogens belonging to the Burkholderia cepacia complex (Bcc). The phylogenetic analysis performed on the 16S rRNA genes affiliated the 140 bacterial strains analyzed to 15 genera. Just three of them ( Psychrobacter, Pseudoalteromonas and Arthrobacter) were shared by the three sponges. The further Random Amplified Polymorphic DNA analysis allowed to demonstrate that microbial communities are highly sponge-specific and a very low degree of genus/species/strain sharing was detected. Data obtained revealed that most of these sponge-associated Antarctic bacteria and belonging to different genera were able to completely inhibit the growth of bacteria belonging to the Bcc. On the other hand, the same Antarctic strains did not have any effect on the growth of other pathogenic bacteria, strongly suggesting that the inhibition is specific for Bcc bacteria. Moreover, the antimicrobial compounds synthesized by the most active Antarctic bacteria are very likely Volatile Organic Compounds (VOCs), a finding that was confirmed by the SPME–GC–MS technique, which revealed the production of a large set of VOCs by a representative set of Antarctic bacteria. The synthesis of these VOCs appeared to be related neither to the presence of pks genes nor the presence of plasmid molecules. The whole body of data obtained in this work indicates that sponge-associated bacteria represent an untapped source for the identification of new antimicrobial compounds and are paving the way for the discovery of new drugs that can be efficiently and successfully used for the treatment of CF infections.

Do bipolar distributions exist in marine sponges? Stylocordyla chupachups sp. nv. (Porifera: Hadromerida) from the Weddell Sea (Antarctic), previously reported as S. borealis (Lovén, 1868)

Sponges are the dominant invertebrates in many Antarctic communities, where they play a decisive structural function thanks to their abundance and large sizes. However, current knowledge on Antarctic sponges remains poor even with respect to basic aspects such as taxonomy. Here, we report on an Antarctic species of the genus Stylocordyla, which has been recorded for a long time under the name of the boreal S. borealis due to spicule and growth habit similarities. A thorough study of dense populations of the only Stylocordyla species known up to now from the eastern zone of the Weddell Sea as well as the re-examination of several specimens (including the type material) of S. borealis has allowed us to assess the variability of the boreal species and to confirm that the austral species is not S. borealis (Loven, 1868) but a new species of Stylocordyla, different from the other congeners recorded from southern latitudes. The new species S. chupachups commonly dwells on horizontal or slighted sloped hard bottoms of the continental shelf of Weddell Sea, from 100 m to below 400 m depth, although the densest populations usually occur between 150 and 300 m. It is a pioneer species in areas that have been scoured by icebergs, and thus its presence may be considered an indicator of recent colonisation.

‘Hitchhiker’ polynoid polychaetes in cold deep waters and their potential influence on benthic soft bottom food webs

AbstractWe describe a new association for Antarctica, involving an holothuroid host,Bathyplotes bongrainiVaney, 1914, and a parasitic polynoid polychaete,Eunoe opalinaMcIntosh, 1885, which lives on the host body. Both species have never been recorded in the study area, the Ross Sea. The ecological definition of this partnership is difficult to assess, being a mix of phoresis, protective association, parasitism and, possibly, kleptocommensalism.Eunoe opalinaemerges also as a true predator, ingesting several food items that do not belong to the diet ofBathyplotes. We compare this association with analogous examples known from shallow tropical environments as well as bathyal and abyssal depths. Given the conspicuous similarities between the deep water and high latitude examples of this kind of association, a possible common origin is hypothesized. Although the role of such a kind of parasitic relationships in Antarctic communities remains to be fully evaluated, it seems evident that, at high latitudes, where trophic levels are simplified and food webs do not have much redundancy, the impact of such a ‘multitasking’ predator-parasite asE. opalinamight be of a greater magnitude than its shallow water tropical counterpart.

Potential impacts of Antarctic bioprospecting and associated commercial activities upon Antarctic science and scientists

The Antarctic Treaty and associated agreements have little to say specifically on bio- prospecting activities within the Treaty area. Consequently, Antarctic bioprospecting has elicited much debate within the Antarctic community, particularly on issues such as benefit sharing between Antarctic Treaty parties, the free availability of scientific data originating in Antarctica and the poten- tial environmental impacts. However, the effect of a further increase in Antarctic bioprospecting activity on Antarctic science, and biologists in particular, in the absence of internationally agreed regulation may deserve further consideration. In this paper we discuss some of the potential issues bioprospecting may present to the Antarctic science community including science funding, personal gain, international scientific collaboration and interactions with industrial partners.

The illustrated moss flora of Antarctica

This is the first modern flora to provide a comprehensive description of all known species and varieties of moss in the Antarctic biome. It complements The liverwort flora of Antarctica (Bednarek-Ochyra et al., 2000), so that now Antarctica can boast the best bryophyte floras of anywhere in the world. A beautiful, self-contained account of what is the major component of the Antarctic flora, this book represents the culmination of many years of meticulous research and extensive fieldwork. The authors' intimate knowledge of the Antarctic biome and of mosses shines through: Ryszard Ochyra is a renowned moss taxonomist; Halina Bednarek-Ochyra is a renowned illustrator and bryophyte taxonomist; and Ronald I. Lewis Smith, until recently a senior ecologist with the British Antarctic Survey, Cambridge, has worked extensively on cryptogam research in Antarctica for over 40 years. Prior to the publication of this volume, identification of Antarctic mosses was often marred by nomenclatural inaccuracies in the literature and misdeterminations of specimens. Similarly, information on the biogeographic zones, environment and moss-dominated communities of the Antarctic could only be obtained by delving into numerous original papers in many journals, often difficult to access. This work now fills a major lacuna not only in bryology but also in plant science as a whole, by accompanying what is a coherent and comprehensive moss flora with extensive information on the biogeography, ecological provinces, climate, geology and vegetation of the Antarctic biome. Bryophytes, and in particular mosses, are the dominant component of the vegetation in ice-free coastal regions of Antarctica. Thus an understanding and appreciation of mosses, their diversity and distribution, is fundamental in any assessment of the effects of climate change in Antarctica. The importance of mosses as model organisms to study the effects of environmental stresses such as cold and water stress (not to mention the impact of changes in natural UV-B radiation as a result of ozone depletion) on land plants is well established and has received a further boost recently with the sequencing of the Physcomitrella genome. Reliable and comprehensive information on Antarctic mosses is also indispensable for any conservation strategy to protect the fragile ecosystems of the Antarctic biome, threatened not only by the changing climate but also by socio-economic pressures, including ever-increasing tourism. The flora describes in detail 111 species and two varieties of mosses in 55 genera from 17 families. It comprises six chapters, together with a glossary of terms and an exhaustive bibliography. Chapters 1 to 5 form an extensive introduction: Chapter 1 includes sections on the biogeography, climate and geology of the Antarctic biome, Chapter 2 is dedicated to the history of muscological investigations in Antarctica, whilst Chapter 3 covers ecology and conservation. Chapter 4 focuses on diversity and phytogeography of the moss flora; it presents theories on the origins of the flora and includes 42 coloured plates illustrating the principal Antarctic moss-dominated communities. These lovely colour pictures and their legends provide important details of habitat features and how these influence the occurrence and development of moss communities (as discussed in Chapter 3). Chapter 5 discusses with clarity the aims and objectives of the work and provides guidance to users of the flora as well as listing comprehensive details of all the specimens examined. The systematic accounts of the taxa are given in Chapter 6; the keys are excellent, the detailed species descriptions are of the highest standard, and the same is true of the superb line drawings. These drawings are not only beautiful but also highly informative, and are provided for each of the species described. The additional comments, including notes on reproduction, habitat and distribution (both Antarctic and global), together with a discussion on diagnostic characters, peculiarities of morphology, taxonomic problems and possible sources of confusion during identification, are invaluable since Antarctic mosses are often environmentally modified and sterile. Armed with this book and its companion volume, The liverwort flora of Antarctica (Bednarek-Ochyra et al., 2000), researchers visiting Antarctica (and with access to a microscope) should be confident that they will be able to identify correctly each and every bryophyte they encounter. This critical assessment of the diversity and biogeography of the Antarctic moss flora will also prove indispensable for other regions, particularly the cool-temperate and cold zones of the Southern Hemisphere, e.g. Tierra del Fuego and The Falklands, which lack modern regional moss floras. In conclusion, this is a highly informative and practical book that will greatly benefit researchers undertaking applied and ecological research on the Antarctic bryoflora, as well as conservation organizations. The first five chapters are very readable and interesting and the systematic treatment of the taxa in Chapter 6 is of the highest standard. I cannot recommend this flora too highly.