Ian Hogg

To assess arthropod distribution and diversity within Victoria Land terrestrial ecosystems, we examined mitochondrial DNA (COI) sequences for three springtail (Collembola) species collected from 12 sites in the vicinity and to the north of the Mackay Glacier. This area is a transitional zone (ecotone) situated between two biogeographic regions (northern and southern Victoria Land). We assessed levels of genetic variability within and among populations of three currently recognised springtail species (Gomphiocephalus hodgsoni, Neocryptopygus nivicolus and Antarcticinella monoculata). We found populations with highly divergent individuals (4-10% sequence divergence) for each of the three putative springtail species within the region. Two of the divergent populations were also from the same area (Towle Glacier) indicating a potentially important site for arthropod diversity. Sampling further provided the first records of species from many of the sites visited. New records for the sprin...

ABSTRACT High Rate Algal Ponds (HRAPs) can provide economical and efficient near tertiary-level wastewater (WW) treatment, with the nutrients recovered as algal biomass. HRAP performance can be negatively affected by the establishment of zooplankton grazers that can consume much of the algal biomass within a few days. Zooplankton management is therefore essential for maintaining WW treatment performance and algal productivity. This paper reviews zooplankton ecology in WW systems and eutrophic environments, and potential methods for zooplankton control in HRAPs. Promising options for zooplankton control include physical methods such as filtration, hydrodynamic cavitation, shear, bead mills; chemical methods such as increase of HRAP night-time CO2 concentration, promotion of the lethal un-ionized ammonia toxicity, use of biocides, and the chitinase inhibitor chitosan; and biocontrol using competitor and predatory organisms. CO2 and phototactic induced migration are proposed to concentrate zooplankton in specific areas to reduce the amount of pond water requiring treatment. Based on this review, we suggest that it may be most beneficial to maintain zooplankton grazer populations at low levels as part of a stable community, rather than to totally eradicate them. This will prevent the ecological imbalance of total control that could result in the establishment of other zooplankton species that are less easy to control.

Background/Question/Methods The Antarctic Dry Valleys are among the most extreme soil environments on earth. In 1903 R.F. Scott described an apparent lack of life in the dry valleys, yet recent evidence reveals microbial diversity comparable to hot deserts. While Scott’s impression has persisted into modern times, an emerging view of the dry valleys suggests a greater potential for biological influence over ecosystem functioning than previously recognized. We present data collected in 2008/2009 by the New Zealand-International Polar Year Terrestrial Antarctic Biological Survey. The goal of this project is to elucidate the factors controlling assembly of soil communities from their most simple manifestation as strictly prokaryotic assemblages to the richest and most productive ecosystems consisting of linked microbial-metazoan trophic groups. Understanding controls over distribution of organisms, assembly of biotic communities and ecological processes is essential to developing hypot...

ABSTRACT The microbial diversity of faecal communities co-existing with mega fauna is not well understood even though these faecal communities are critical for health and development. Additionally, the transfer of microbial taxa among host animals is little studied. Here, we used 16S sequences obtained from clone libraries to characterise the faecal microbiota of Weddell seals breeding in McMurdo Sound and at White Island, Antarctica. Faecal bacterial communities were dominated by four phyla; Actinobacteria (20 %), Bacteroidetes (13 %), Firmicutes (23 %), and Proteobacteria (13 %). We also used automated ribosomal intergenic spacer analysis to examine the dispersal of bacteria between populations of Weddell seals breeding at White Island and in McMurdo Sound. The Weddell seals at White Island are isolated by the Ross Ice Shelf from the larger population of Weddell seals breeding in McMurdo Sound. We found that the faecal bacteria communities of the seals at White Island had lower diversity and that the community composition was significantly different compared with the seals in the McMurdo Sound area.

1We examined fluctuating asymmetry (FA) among individuals of the stream-dwelling stonefly Nemoura trispinosa (Plecoptera: Nemouridae) to determine whether individuals exposed to an increase of 2–3·5 °C in water temperature would show greater FA than reference (control) individuals.2Mature nymphs were collected from two adjacent channels (one experimental, one control) in a longitudinally divided stream both before and during a 2-year temperature manipulation. No consistent differences were found between the experimental and control channels for any measure of FA.3Four additional reference sites were studied to estimate ‘natural’ variation in FA, and to assess any relationship between FA and population genetic structure (e.g. heterozygosity). Variation in FA among these sites was greater than that resulting from the manipulation. Allozyme analysis indicated low to moderate levels of genetic differentiation among sites (Wright’s FST mean = 0·06, maximum = 0·13) and there were negative correlations between FA and heterozygosity (Hexp).4We surveyed experimental studies published since 1996 to evaluate the generality of our results. Of 44 comparisons examining an association between an experimental stress and FA, 19 (43·2%) failed to detect any relationship. This pattern did not depend on the taxonomic group or the number or type of traits, although some stressors appeared to be more likely to produce an increase in FA than others.5We conclude that FA may be unreliable for detecting subtle biological changes resulting from small temperature shifts, and concur with others that the technique should be viewed with extreme caution as a monitoring tool.We examined fluctuating asymmetry (FA) among individuals of the stream-dwelling stonefly Nemoura trispinosa (Plecoptera: Nemouridae) to determine whether individuals exposed to an increase of 2–3·5 °C in water temperature would show greater FA than reference (control) individuals.Mature nymphs were collected from two adjacent channels (one experimental, one control) in a longitudinally divided stream both before and during a 2-year temperature manipulation. No consistent differences were found between the experimental and control channels for any measure of FA.Four additional reference sites were studied to estimate ‘natural’ variation in FA, and to assess any relationship between FA and population genetic structure (e.g. heterozygosity). Variation in FA among these sites was greater than that resulting from the manipulation. Allozyme analysis indicated low to moderate levels of genetic differentiation among sites (Wright’s FST mean = 0·06, maximum = 0·13) and there were negative correlations between FA and heterozygosity (Hexp).We surveyed experimental studies published since 1996 to evaluate the generality of our results. Of 44 comparisons examining an association between an experimental stress and FA, 19 (43·2%) failed to detect any relationship. This pattern did not depend on the taxonomic group or the number or type of traits, although some stressors appeared to be more likely to produce an increase in FA than others.We conclude that FA may be unreliable for detecting subtle biological changes resulting from small temperature shifts, and concur with others that the technique should be viewed with extreme caution as a monitoring tool.