Tardigrades of the Australian Antarctic Territories: the Windmill Islands, East Antarctica

Six species of tardigrades, Pseudechiniscus suillus, Macrobiotus sp., Hypsibius antarcticus, Ramajendas frigidus, Diphascon chilenense and Diphascon pingue were extracted from mosses and lichens from the ice-free regions of the Windmill Islands near Casey Base, East Antarctica. Significant positive associations were found between the three common species ( Pseudechiniscus suillus, Hypsibius antarcticus, Diphascon chilenense ) and bryophytes, whereas strong negative associations were found between these species and algae and lichens. There were additional interspecific associations between the common species of tardigrades as well as between tardigrades, nematodes and rotifers.     

Abundance and diversity of soil invertebrates in the Windmill Islands region,East Antarctica

The harsh climate and patchy distribution of habitable terrestrial ecosystems constrain soil invertebrate communities in continental Antarctica. The Windmill Islands in East Antarctica have a relatively gentle climate by Antarctic standards, and the region supports some of the most well-developed moss beds on the continent. These moss beds and soils are known to sustain invertebrate communities dominated by nematodes, rotifers and tardigrades, but our knowledge of the diversity and composition of these communities remains limited. We extracted soil fauna from 74 soil samples representing a wide range of microhabitats, and 24 moss samples, collected at Clark Peninsula, Bailey Peninsula and Robinson Ridge in the Windmill Islands during the 2012–2013 austral summer. Invertebrates were present in all samples, but densities varied considerably both within and between sites with limited correlation with edaphic variables or cover type. Taxa found included two species of nematodes (Plectus murrayi; Plectus frigophilus), one mite (Nanorchestes antarcticus) as well as tardigrades and rotifers (enumerated only). No springtails were found in this study, but individuals of the genus Cryptopygus were later recovered from moss collected near Casey Station. The Windmill Islands soils and moss beds support dense populations of soil fauna. However, despite the relatively mild climate conditions and favorable soil properties, species diversity is low. The diversity is possibly limited by recent deglaciation and limited dispersal opportunities to the region. Given favorable local conditions, it is likely that colonizing species will perform well, whether these arrive by natural means or are accidentally introduced by humans.     

The distribution and abundance of soft-sediment macrobenthos around Casey Station, East Antarctica

Grab samples of shallow (5–35 m) marine benthic sediments and epi- and infaunal assemblages were taken from nearshore regions around Casey Station, Windmill Islands, East Antarctica. A hierarchical, spatially nested sampling design was used with locations (kilometres apart), sites (hundreds of metres apart) and plots (tens of metres). Two potentially impacted, polluted locations (adjacent to a sewage outfall and an old garbage tip) were compared with two control locations in an asymmetrical design. Significant differences in assemblages were found between locations and between sites within locations. Significant differences in the abundances of taxa at several taxonomic levels (species, family, order, phylum) were found at all three spatial scales. Significant differences were also detected between the polluted and control locations. Compared with other Antarctic locations, the assemblages were dominated by crustaceans (90–97% of individuals) and there was a paucity of polychaete fauna at the locations sampled. Accepted: 3 June 2000     

Benthic feeding by krill, Euphausia superba Dana, in coastal waters off West Antarctica and in Admiralty Bay, South Shetland Islands

Diatoms in the food of krill caught in the summer in coastal waters close to the South Shetland Islands and in the summer and three winters in Admiralty Bay, King George Island were investigated. The diatoms were used as indicators of sources of krill food. Principal component analysis divided the diatom taxa into two groups, one being pelagic diatoms and from the food of krill in coastal waters, and the other being benthic diatoms and taxa from the food of krill in Admiralty Bay. All pelagic taxa of diatoms were consumed by krill. In the summer in coastal waters, benthic diatoms in krill food originated from the sublittoral. In the summer in Admiralty Bay, besides phytoplankton, diatoms were noted from the sublittoral and littoral in the food of krill. However, in the winter mostly sublittoral and epiphytic diatoms were present in krill food. Accepted: 20 March 2000     

10. Snow algae of the Windmill Islands region, Antarctica

A list of the 24 species of snow algae identified from the region, a resume of what is currently known about the major species, and avenues for further research are provided. New species discovered include 2 Desmotetra spp., one Chlorosarcina sp., 2 Chloromonas spp. and a Palmellopsis sp. Several of these are from genera whose members have previously been found only in the soil flora. Not only was it necessary to elucidate the life cycle of these species, but it was also essential to examine them ultrastructurally to determine their taxonomic positions.     

Penicillium species from terrestrial habitats in the Windmill Islands, East Antarctica, including a new species, Penicillium antarcticum

This paper documents the Penicillium species associated with the naturally occurring plants and animals in the Windmill Islands, East Antarctica. An attempt has been made to establish the species associations between the Penicillia and the mosses and birds. The species found are discussed briefly in terms of taxonomy and biological significance, and a new species, Penicillium antarcticum, is described. Accepted: 27 July 1998     

The broad-scale distribution of microfungi in the Windmill Islands region, continental Antarctica

Microfungi were isolated from soils, mosses, algae and lichens in the Windmill Islands region of Antarctica. From a total of 1,228 isolates, 22 genera were identified. The most frequently isolated fungi from mosses were Mycelia sterilia (47% of total isolates), Phoma spp. (18%), Penicillium spp. (11%), Chrysosporium spp. (7%) and Thelebolus microsporus (6%). Mycelia sterilia, Penicillium spp., Mortierella spp., Chrysosporium cf. pannorum and Thelebolus microsporus were also frequently isolated from algae. Fungal distribution and diversity were poor in samples of lichens, compared to samples from mosses and algae. The frequency of occurrence of microfungi was most often associated with strong biotic influence. There was a marked increase in fungal diversity in human-disturbed sites. Twelve taxa were restricted to soils from near the Australian Casey Station, suggesting significant introduction of fungi into this environment by human activities. Away from the station, fungal distribution appeared to be related to substrata and nutrient status rather than dispersal opportunities. Suggestions for future research and the need for constant monitoring to clarify the role of human disturbance on Antarctic fungi are discussed. Received: 1 April 1997 / Accepted: 17 August 1997     

Phytogeography of bryophyte and lichen vegetation in the Windmill Islands,Wilkes Land,Continental Antarctica

The distribution and frequency of bryophyte and lichen vegetation on ice-free regions of the Windmill Islands are presented using data derived from aerial photography and ground surveying. The qualitative and quantitative plant cover of sites are listed and related to the topography and major soil characteristics of each site. The richest associations of macrolichens and bryophytes occurred on the metamorphic northern peninsulas. Species richness and frequency was generally reduced on the charnockitic southern peninsula and the islands which have been deglaciated longer. Salinity varied significantly throughout the region with the highest levels in the northern islands reflecting the presence of penguin colonies. In such sites bryophytes and lichens were virtually absent. Wind blown sea-spray contributed far less salts than direct excretion from penguins. On the peninsulas snow cover and site exposure appeared to delimit plant distribution. Higher salt levels from sea-spray on the northern aspects of the peninsulas seemed to have negligible impact on vegetation patterns with the possible exception ofBiatorella cerebriformis which was encountered only inland. The total phosphorus and nitrogen levels of the skeletal soils were generally low except in eutrophic sites adjacent to penguin colonies. The vegetation patterns are discussed in terms of the climate, topography and species autecology.     

Field photosynthetic activity of lichens in the Windmill Islands oasis, Wilkes Land, continental Antarctica

In order to ascertain whether the major species of continental antarctic macrolichens are photosynthetically active during summer conditions, the chlorophyll fluorescence of three lichen species [Umbilicarin decussata (Vill. Zahlbr., Pseudephebe minuscula (Ny-l. ex Arnold) Brodo and Hawksw. and Usnea sphacetala R. Br.] was monitored in the vicinity of Casey Station. Wilkes Land, continental Antarctica using a PAM-2000 modulated fluorescence system. Lichens were studied when in equilibrium with the atmosphere as well as when moistened by snow showers. Photochemical quantum yield was estimated as ΔF/F′_m and related to thallus water content as well as microclimatic conditions. Lichens were photosynthetically active only when moistened by snow fall or by run-off from snow melt. The levels of photosynthetic activity in the field for all species were influenced by microenvironmental conditions and patterns in response were site and species specific. Highest levels of photosynthetic efficiency occurred when thalli were at intermediate water contents. Photosynthetic activity was reduced by cold as well as warm, bright conditions. Highest thallus water contents occurred during the middle of the day after substantial “falls of snow. P. minuscula maintained highest thallus water contents at all sites and appears to have a high water compensation point which is related to its observed distribution patterns. Umbilicaria decussata studied in the laboratory did not become photosynthetically active even when exposed to 95% relative humidity (RH) for 51 h and. when dehydrating after artificial wetting, showed an optimum thallus water content for photosynthesis of ca 90% dry weight and a thallus water compensation point of about 35% dry weighl. In the field U. decussata did not become pholosynthetically active except when moistened by snow. Usnea sphacelata exposed to the atmosphere had low thallus water contents (ca 30%) which was not related to RH. The results indicate that the lichens are photosynthetically inactive for most of the summer period and are totally reliant on snow as a water supply. This i.s important when modelling carbon gain and growth rates of continental antarctic lichens.     

Foods of the South Polar skua Catharacta maccormicki at Ardery Island, Windmill Islands, Antarctica

South Polar skuas (Catharacta maccormicki) breed on Ardery Island in the absence of a local breeding population of Adelie penguins (Pygoscelis adeliae). Assessment was made of the food remains in skua feeding territories in 1995/1996. The diet of South Polar skuas largely consisted of fulmarine petrel species which bred on Ardery Island. Southern fulmar (Fulmarus glacialoides) remains were the predominant prey items found, and skuas appeared to feed preferentially on this species. Accepted: 3 June 2000     

Biosurfactant Production by Halotolerant Rhodococcus fascians from Casey Station, Wilkes Land, Antarctica

Isolate A-3 from Antarctic soil in Casey Station, Wilkes Land, was characterized for growth on hydrocarbons. Use of glucose or kerosene as a sole carbon source in the culture medium favoured biosynthesis of surfactant which, by thin-layer chromatography, indicated the formation of a rhamnose-containing glycolipid. This compound lowered the surface tension at the air/water interface to 27 mN/m as well as inhibited the growth of B. subtilis ATCC 6633 and exhibited hemolytic activity. A highly hydrophobic surface of the cells suggests that uptake occurs via a direct cell–hydrocarbon substrate contact. Strain A-3 is Gram-positive, halotolerant, catalase positive, urease negative and has rod–coccus shape. Its cell walls contained meso-diaminopimelic acid. Phylogenetic analysis based on comparative analysis of 16S rRNA gene sequences revealed that strain A-3 is closely related to Rhodococcus fascians with which it shares 100% sequence similarity. This is the first report on rhamnose-containing biosurfactant production by Rhodococcus fascians isolated from Antarctic soil.     

Rates of soluble carbohydrate utilization in soils from the Windmill Islands Oasis,Wilkes Land,continental Antarctica

A time course study of the fate of glucose, sucrose, and arabitol added to surface soils collected from vegetated and bare sites near Casey Station, Wilkes Land, Antarctica, was performed using gas-liquid chromatography. For both soils, hydrolysis of added sucrose was observed after 24 hours. Following 168 hours incubation at both 5°C and 15°C, hydrolysis of sucrose to glucose and fructose was greater than 95%. Maximum rates of sugar uptake were observed in soils from the vegetated site incubated at 15°C. After 168 hours 44%, 52% and 94% of the added arabitol, glucose and sucrose respectively had been consumed. There did not appear to be any cell-free extracellular enzymatic activity in the soils as levels of added sucrose, trehalose and maltose within soil water extracts showed no change after 168 hours incubation. The results are discussed in relation to earlier work on the microbial activity of Antarctic soils and the sources of carbohydrate input into this ecosystem.     

Moss Communities and Their Characteristics in Ice-free Areas of the Windmill Islands,Wilkes Land,Continental Antarctica

The moss vegetation of the Windmill Islands can be classified into the following seven communities: 1.Grimmia antarctici community; 2. G. antarctici-Ceratodon purpureus community; 3. Bryum pseudotriquetrum community; 4. G. antarctici-B, pseudotriquetrum community; 5. Ceratodon purpureus community; 6. C. purpureus-G, antarctici community; 7. C. purpureus B. pseudotriquetrum community. Communities 1, 3, 4 and 7 occur in wet habitats while communities 5 and 6 are found in rather dry habitats, community 2 distributes between dry and wet habitats. Microtopography governs the distribution of water supply and therefore community types. Stable moss communities usually form moss hummocks and hollows. Species composition, colour and height of the hummocks determines the vertical structure of the moss community layers with 2-3 strata being discernible and level structure forming mosaic. Other phytocoenological characteristics of the moss communities, such as the dense moss cushions, asexual reproduction (although antheridia or archegonia have been found in each of the species), abundance of epiphytic algae and lichens growing on the surface of moss hummocks, the colour change of some species in different habitats, appear related to moisture availability, light intensity, wind exposure and temperature.     

Human impacts in soft‐sediment assemblages at Casey Station,East Antarctica: Spatial variation,taxonomic resolution and data transformation

Abstract Differences between marine soft‐sediment assemblages at disturbed (two waste dumps, a sewage outfall and a wharf) and control locations were found at Casey Station, Antarctica. These differences were significant against considerable background spatial variability. Core samples were collected by divers using a hierarchical, spatially nested sampling design incorporating four scales: (i) locations (thousands of metres apart); (ii) sites (hundreds of metres apart); (iii) plots (tens of metres apart); and (iv) among replicates within plots (approximately 1 metre apart). Control locations had greater species richness and diversity than disturbed locations and there were many taxa found at control locations that were not recorded at disturbed locations. Assemblages at disturbed locations were less variable than those at control locations. In contrast, populations of some dominant species were more variable at disturbed locations than at control locations. Significant variation in populations of individual taxa was also found at all scales and although greatest at the level of location, variation was also large at the smallest scale, between replicate cores, indicating significant small‐scale patchiness in populations of taxa. Patterns of assemblage structure were similar at fine (77 taxa) and medium (aggregated to 33 taxa) levels of taxonomic resolution, but changed at coarse levels of resolution (nine phyla). Soft‐sediment assemblages at Casey Station are markedly different from those reported from other areas of Antarctica. Assemblages at Casey are almost completely dominated by crustaceans (up to 99% total abundance) and polychaetes are rare or in very low abundances in most areas investigated in the region. This is also the first demonstration that small Antarctic research stations (population 20–50 people) may cause impacts that are detectable in the adjacent marine environment.     

Assemblages of necrophagous animals off Enderby Land, East Antarctica

A hyperbenthic baited trap was deployed at three sites in Lützow-Holm Bay and off Enderby Land, Antarctica, in the 1993/1994 summer to investigate the species composition, distribution, and abundance of necrophagous animals. The trap consisted of four chambers, with a length of 100 cm and a diameter of 38 cm. The sample at the abyssal site, 3,186 m deep, contained 74 individuals of 6 species, completely different from that at the other 2 sites on the continental shelf; it was dominated by the large amphipod Eurythenes gryllus, a cosmopolitan species recorded from bathyal to abyssal depths. The species composition of the continental shelf sites, 93-137 individuals of 10-12 species, was dominated by species endemic to Antarctica, such as the small amphipod Pseudorchomene coatsi and the isopod Natatolana meridionalis; in these continental shelf sites, a high degree of species diversity was observed.     

Snow algae of the Windmill Islands, continental Antarctica 3. Chloromonas polyptera (Volvocales, Chlorophyta)

A new name, Chloromonas hohamii, is proposed to accommodate a common North American snow alga previously incorrectly referred to as Chloromonas polyptera. Chloromonas hohamii differs in having the motile vegetative cells with a cup-shaped chloroplast opening in the anterior end of the cell, shorter, narrower, ellipsoidal to elongate to somewhat fusiform, sexual spores with non-spiralled wall flanges, shorter and narrower daughter cells derived from the spores, and it grows in snow of significantly lower pH and conductivity. Received: 29 August 1997 / Accepted: 24 April 1998     

DGGE fingerprinting of bacteria in soils from eight ecologically different sites around Casey Station,Antarctica

Bacterial community structures in soils collected from eight sites around Casey Station, Antarctica, were investigated using denaturing gradient gel electrophoresis (DGGE) of amplified 16S rRNA gene fragments. Higher bacterial diversity was found in soils from protected or relatively low human-impacted sites in comparison to highly impacted sites. However, the highest diversity was detected in samples from Wilkes Tip, a former waste disposal site that has been undisturbed for the last 50 years. Comparison of community structure based on non-metric multidimensional scaling plots revealed that all sites, except the hydrocarbon-contaminated (oil spill) site, were clustered with a 45% similarity. A total of 23 partial 16S rRNA gene sequences were obtained from the excised DGGE bands, with the majority of the sequences closely related to those of the Cytophaga–Flexibacter–Bacteroides group. No significant correlation was established between environmental variables, including soil pH, electrical conductivity, carbon, nitrogen, water content and heavy metals, with bacterial diversity across the eight study sites.     

Distribution and abundance of snow petrels<Emphasis Type="Italic"> Pagodroma nivea</Emphasis> in the Windmill Islands,East Antarctica

In light of a paucity of available data on snow-petrel breeding areas and population sizes in the Australian Antarctic Territory, we undertook a systematic regional survey in the Windmill Islands during the 2002/2003 summer. Snow petrels were found breeding at most ice-free localities at varying densities. A total of 4,034 active snow-petrel nests were located; 83% of these active nests were located in the southern half of the survey area. Based on the surveys, we provide distribution maps of nesting areas at a regional scale and estimate the total breeding population at approximately 12,200 pairs.     

Filamentous fungi of the Windmill Islands, continental Antarctica. Effect of water content in moss turves on fungal diversity

This study presents the effect of water content in moss turves from the Windmill Islands, Wilkes Land, continental Antarctica on the composition of associated filamentous fungi. The two most prevalent mosses were sampled: Grimmia antarctici and Bryum pseudotriquetrum. Results were expressed as dry weights. No relationship was found between water content of the mosses or the surrounding soil and fungal diversity. Ten species of fungi were recovered and all species belong to cosmopolitan taxa. Accepted: 21 June 1999     

山东近海鱼类群落分类多样性

根据相关文献整理了山东近海鱼类名录,并根据1998—2009年山东近海鱼类调查名录,应用平均分类差异指数(Δ+)和分类差异变异指数(Λ+)研究了鱼类分类学多样性特征。结果表明,山东近海鱼类名录包括2纲28目91科169属225种,1998年调查仅2纲11目41科58属62种,2006年调查为1纲13目41科71属78种,2009年调查为1纲9目32科55属62种。1998年—2009年调查鱼类种类远远低于鱼类名录记录的种数,分类阶元包含指数较低,平均每属包含1.1种。根据山东近海鱼类名录计算鱼类平均分类差异指数为66.1,分类差异变异指数为141.7;1998—2009年历次调查鱼类平均分类差异指数在60.9—62.7之间,分类差异变异指数在65.4—92.3之间。将1998—2009年历次调查鱼类群落分类多样性指数计算值叠加到山东近海鱼类总名录的95%置信漏斗曲线图,结果表明大部分调查值在置信漏斗曲线之外,目前山东近海鱼类分类多样性已大幅下降。