This study provides the first quantitative analysis of the littoral and supralittoral arthropod assemblages of sub-Antarctic Marion Island. Seventeen mite species (126 203 individuals) from 11 families were found on the shore at Macaroni Bay. Three families dominated the assemblages in both abundance and diversity: the Hyadesiidae, Ameronothridae and Halacaridae. Six insect species from three orders were found on the shore. Species richness increased from one in the littoral, to four and two species in the Mastodia and Caloplaca zones, respectively. The littoral, chironomid midge, Telmatogeton amphibius was the most abundant insect species, constituting 80% of all insects counted. Arthropod assemblages corresponded closely to the cryptogram dominated zonation patterns previously identified for the Marion Island shore. This clear association between arthropod and cryptogam zonation patterns provided a clear indication of habitat specificity in many of the species, and a quantitative analysis of habitat specificity on a species by species basis supported this tenet. The specificity of most species to the shore, which forms part of the epilithic biotope, is most likely a consequence of the considerable age of this biotope compared to the younger, post-glacial vascular vegetation. Tourist species, i.e. species transient to an assemblage, inflated species richness in zones and the distribution ranges of species across zones. It is suggested that previous, qualitative analyses of shoreline arthropod communities may have overestimated species ranges and richnesses because of the inclusion of tourist species. It is suggested that if a sound understanding of patterns in and processes underlying Antarctic arthropod assemblages is to be achieved, quantitative analyses must be expanded in the region. In this study the spatial patterns of littoral and supralittoral arthropods from sub-Antarctic Marion Island are examined. Primary consumers were by far the most diverse group on the shore, with nine algivore and ten fungivore species from a total of 23 species. Positive species associations were found in the Mastodia and Caloplaca zones and positive abundance covariation in the Verrucaria, Mastodia and Caloplaca zones. There were no negative associations between any taxa, indicating that interspecific interactions on the shore are either minimal or absent. Significant interactions were related to the diversity of the respective habitats, with higher diversity resulting in higher levels of positive associations and abundance covariation. High levels of aggregation clearly demonstrated that species were not randomly distributed within habitats. Intraspecific aggregation was generally higher than interspecific aggregation in the five habitats and if competition was to occur it would most likely be among conspecifics. The absence of suitable biological information for species precluded further analyses of competition. However, if competitive interactions were found to occur between heterospecifics then coexistence would best be explained using the aggregated nature of superior competitors, allowing weaker competitors to coexist in zones. Positive associations between species were attributed to favourable environmental conditions, the availability of limiting resources (e.g. shelter) and the structure of the dominant cryptogram species. Body sizes, spanning five orders of magnitude (0.5 J.1g - 26 mg), were measured for 59 of the approximately 120 invertebrate species on Marion Island. Mass-length and fresh-dry mass relationships were calculated for orders, families and species (for those with sufficient data). A comparison of their slopes indicates that for prediction of body mass it may be useful to use regressions from the lowest taxonomic rank possible. Differences between the mass-length relationship for Marion Island insects (log mass = -4.294 + 3.151 log length) and other relationships on continental assemblages raises the questions as to the applicability of these results. This study should prove useful for estimating body sizes for other, similar taxa in the Antarctic and provide baseline information on an important species trait that seems to be changing with local and global environmental changes. / Dissertation (MSc (Entomology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

<p>The major aim of this study is to determine and compare the distribution of bacteria and actinobacteria in Marion Island terrestrial habitats.</p>

<p>The major aim of this study is to determine and compare the distribution of bacteria and actinobacteria in Marion Island terrestrial habitats.</p>

Philosophiae Doctor - PhD (Biotechnology) / The major aim of this study is to determine and compare the distribution of bacteria and actinobacteria in Marion Island terrestrial habitats. / South Africa

In this study macro-invertebrates were sampled quantitatively in 10 lowland vegetation communities on Marion Island over a one-year period commencing in May 1996 as part of a larger investigation into the distribution, abundance and species energy use of invertebrates across an altitudinal transect on Marion Island. The data collected for this particular study were used to investigate the habitat specificity and seasonality of the macro-invertebrates, as well as the impact of alien species on the local community. As part of the latter study a watching brief for alien species was kept throughout the field year and the alien species list was updated accordingly. The quantitative data were also used to compare changes in the density and biomass of selected macro-invertebrate species between 1976/77 and 1996/97 by reworking the data on macro-invertebrates collected by Alan Burger in 1976/77 during the course of his work on the Lesser Sheathbill. In the current study it was found that the majority of the macro-invertebrate species are not particularly habitat specific. Rather, they generally prefer either moist mire habitats, or the more well-drained non-mire vegetation complexes. In addition, many of the species had pronounced peaks in abundance in a given season (winter, summer, autumn and spring peaks were recorded), although this seasonality varied between species and between habitats for a given species. Although this finding does not support previous generalizations concerning an absence of seasonality in sub-Antarctic invertebrates, it does show that sub-Antarctic invertebrates, like their Antarctic counterparts, may have extremely flexible life history strategies. Limnophyes minimus was found to be one of the most abundant alien species on the island, and reached high densities in most of the plant communities sampled, with the highest density being recorded in the Cotula plumosa biotically influenced community (annual mean of 4365 individuals.m-2 ) and the lowest in the Crassula moschata salt spray community (annual mean of 41 individuals.m-2 ). Estimates of litter ingestion indicated that L. minimus larvae are capable of consuming between 0.07 and 8.54 g(dry mass)·m-2 per year, depending on the community. In some communities this litter consumption amounted to an order of magnitude more than that consumed by Pringleophaga marioni (Lepidoptera, Tineidae). Although the larvae of this moth species are thought to represent the bottleneck to nutrient recycling on the island, this study showed that midge larvae may also contribute substantially to this process. As a consequence, the considerable changes that have been predicted to occur in Marion Island's terrestrial ecosystem as a consequence of enhanced predation by mice on P. marioni larvae, may be retarded or obscured by the contribution of the midge larvae to nutrient cycling. Hence, it is suggested that greater attention be given to the small and inconspicuous elements of the alien sub-Antarctic faunas because such species may have profound consequences for ecosystem functioning on these islands. The likely impact of alien species on the terrestrial macro-invertebrates, and the communities they belong to, was further highlighted by the dramatic decline in the biomasses of the macro-invertebrates between 1976/77 and 1996/97. Significant declines in biomass of between 83-97% were found for Lepidoptera larvae (mostly Pringleophaga marioni) and for weevils, the major prey species of the introduced house mouse between 1976/77 and 1996/97, although non-prey species appear to have shown either no changes (the indigenous snail Notodicus hookeri) or increases in abundance (the introduced slug Deroceras caruanae). However, differences in sampling strategies adopted by these two studies and others investigating macro-invertebrate abundances mean that the current results may well be underestimates of change, while other studies must be interpreted with considerable caution. Nonetheless, the current findings and those of authors suggest that mice may be having pronounced impacts on the terrestrial ecosystem at Marion Island. In sum, the findings of this thesis indicate that considerably more attention must be given to well-planned collaborative work to address critically important management questions, identified by the Prince Edward Island Management Committee, and that considerable care must be taken to prevent the further introduction of alien species to sub-Antarctic islands. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted

Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: To estimate nutrient budgets and model nutrient cycling at a whole ecosystem level on sub-Antarctic Marion Island requires information on the spatial variability of plant nutrient concentrations on the island. The complexity of constructing budgets and models will also be reduced if, instead of considering each plant species individually, the species can be grouped on the basis of their similarities/differences in nutrient concentrations. This thesis presents the results of an investigation into both these aspects. Altitude and distance from the sea are highly correlated with each other and thus influence the concentrations of all the nutrients considered (N, P, K, Ca, Mg and Na) very similarly. Concentrations of N, P and Na in living leaves, dead leaves, stems and roots decrease going inland, due to a decline in the influence of animal manuring and of sea spray. Ca concentration increases going inland, away from the organic peats characteristic of the lowland regions toward the mineral rawmark inland soils. Declining sea spray and increasing soil minerality going inland both affect plant Mg concentration; the net effect is a slight decrease in Mg concentration going away from the coast. K concentration in living leaves and roots did not change going inland; dead leaf and stem K concentrations showed a weak decline. Bryophyte shoot nutrient concentrations do not show such marked patterns of change going inland. Considering the bryophyte species as a whole, the only significant effect is that shoot Na concentration decreases, and Ca concentration increases, going inland. Although information on nutrient concentrations in all plant organs from all four (N, E, W and S) sides of the island was available for only a few species, and in many instances the between-side effect was not significant for individual species, the pattern of between-side differences is quite clear. Living leaf N, P and Mg concentrations are higher in west side than east side plants, with south and north side plants having intermediate concentrations. Leaf K concentrations are highest on the north and lowest on the west side, with east and south side concentrations being intermediate. Leaf Ca concentrations are highest on the south side and lowest on the north side, with east and west side Ca concentrations being intermediate. Leaf Na concentration declines more sharply with distance inland on the island's western and southern sides than on its eastern and northern sides, so that closer than 450 m from the shore leaf Na concentration is higher on the west and south than on the east or north sides, but further inland than that the difference lessens. There was sufficient information for dead leaf, stem and root nutrient concentrations only for the west and east sides of the island. West-east differences in nutrient concentrations of dead leaves are the same as for living leaves. Stem and root west-east concentration differences are also similar to those for living leaves, except for P and Mg concentrations, which were similar on the two sides. All organs showed the same steeper decline in Na concentration on the west than on the east side of the island. Bryophytes show somewhat different between-side nutrient concentration patterns to the vascular plants. South side (not west) bryophytes have highest N and P concentrations but, like for the vascular plants, east side bryophytes have the lowest N and P concentrations. Also similar to the vascular plants, bryophyte K concentration is highest on the north side and lowest on the west side, although south side concentrations are nearly as high as the north side ones. Unlike the vascular plant leaves, bryophyte Mg concentration is highest on the south (not west) side and lowest on the north (not east) side, with east and west side concentrations being intermediate. South side bryophytes have highest Ca and Na concentrations, similar to the vascular plant pattern. Ordination and clustering analyses of leaf nutrient concentrations suggested five nutrient type clusters amongst the island's plant species. The clusters differ in the amount (low, moderate or high) of N, P, K and Na versus the amount of Ca and Mg. Species membership of the clusters is strongly related to what major taxonomic group (bryophyte, pteridophyte, monocot or dicot) the species belongs to, but habitat factors, especially the intensity of animal manuring, also play a role. Plant guilds compiled previously for the island and which have been suggested might prove useful for modeling nutrient standing stocks on a whole island basis associate poorly with the clusters. Where a particular guild does associate closely with a cluster it is mostly an effect of taxonomic group (the guild members are all from a single taxonomic group) or habitat (the guild members are typical for a particular habitat). It is suggested that in order to reduce the complexity and arduousness of constructing whole island plant nutrient standing stock budgets, the species should be grouped according to their taxonomy – as bryophytes, dicots, monocots, club mosses or pteridophytes (the ferns proper). Subgroups of these taxonomic groups can be constructed on the basis of habitat. Mostly, this will be necessary to distinguish plants from manured habitats from plants of the same species from unmanured ones. / AFRIKAANSE OPSOMMING: Ten einde die voedingstofvoorrade en modelvoedingstofsiklus op die sub-Antarktiese Marioneiland op 'n algehele ekosisteemvlak te raam, word inligting oor die ruimtelike variasie in plantvoedingstofkonsentrasies op die eiland benodig. Die raming van voorrade en die konstruksie van modelle sal ook minder ingewikkeld wees indien plantspesies op grond van hul ooreenkomste/verskille in voedingstofkonsentrasies gegroepeer word eerder as om elke spesie individueel te beskou. Hierdie tesis bied 'n uiteensetting van die ruimtelike variasie (hoogte, afstand van die see én kant van die eiland) in die chemiese samestelling (N, P, K, Ca, Mg en Na) van plante, en probeer die plantspesies op grond daarvan in voedingstoftipes klassifiseer. Hoogte en afstand van die see is nou verwant en beïnvloed dus voedingstofkonsentrasies op feitlik dieselfde manier. N-, P- en Na-konsentrasies in lewende blare, dooie blare, stingels en wortels neem af in die rigting van die binneland weens 'n afname in die invloed van dierebemesting en seesproei. Ca-konsentrasies styg weer namate daar vanaf die organiese veengrondkenmerke van die laagliggende streke na die mineraalryke binnelandse grond beweeg word. Sowel die afname in seesproei as die toename in grondmineraalgehalte in die rigting van die binneland beïnvloed die Mg-konsentrasie in plante; die netto uitwerking is 'n effense afname in Mg-konsentrasie namate daar wegbeweeg word van die kus. Die K-konsentrasie in lewende blare en wortels verander nie in die rigting van die binneland nie, terwyl dié in dooie blare en stingels 'n geringe afname toon. Die voedingstofkonsentrasies in briofietspruite toon egter nie dieselfde merkbare veranderingspatrone in die rigting van die binneland nie. Wat die briofietspesie in die geheel betref, is die enigste beduidende uitwerking dat die Na-konsentrasie in spruite afneem en die Ca-konsentrasie toeneem namate daar na die binneland beweeg word. Die N-, P- en Mg-konsentrasies in lewende blare is hoër by plante in die weste as in die ooste van die eiland, en plante in die suide en noorde toon tussenkonsentrasies. K-konsentrasies in blare is die hoogste in die noorde en die laagste in die weste, met tussenkonsentrasies in die ooste en suide. Ca-konsentrasies in blare is weer die hoogste in die suide en die laagste in die noorde, met tussenkonsentrasies in die ooste en weste. Aan die weste- en suidekant van die eiland toon Na-konsentrasies in blare 'n skerper afname namate daar verder van die see beweeg word as aan die ooste- en noordekant. Verskille in die voedingstofkonsentrasies van dooie blare in die weste en ooste is dieselfde as vir lewende blare. Konsentrasieverskille in stingels en wortels in die weste en ooste is ook soortgelyk aan dié in lewende blare, buiten P- en Mg-konsentrasies, wat dieselfde was aan albei kante. Alle plantorgane toon dieselfde skerper afname in Na-konsentrasies in die weste as in die ooste van die eiland. Die voedingstofkonsentrasiepatrone tussen die verskillende kante van die eiland was ietwat anders vir briofiete as vir vaatplante. Briofiete in die suide (nie die weste nie) het die hoogste N- en P-konsentrasies. Soos die vaatplante, het die briofiete in die ooste die laagste N- en P-konsentrasies. Óók soortgelyk aan die vaatplante, is die K-konsentrasie van briofiete die hoogste in die noorde en die laagste in die weste, hoewel konsentrasies in die suide bykans so hoog is as dié in die noorde. In teenstelling met die blare van vaatplante, is die Mg-konsentrasie van briofiete die hoogste in die suide (nie die weste nie) en die laagste in die noorde (nie die ooste nie), met tussenkonsentrasies in die ooste en weste. Briofiete in die suide het die hoogste Ca- en Na-konsentrasies, wat weer ooreenstem met die vaatplantpatroon. Ordinasie- en trosvormingsontledings van voedingstofkonsentrasies in blare dui op vyf voedingstoftipes onder die plantspesies op die eiland, op grond van die (klein, matige of groot) hoeveelheid N, P, K en Na teenoor die hoeveelheid Ca en Mg. Die klas waartoe 'n spesie behoort, hou sterk verband met sy hoof- taksonomiese groep (briofiet, pteridofiet, monokotiel of dikotiel), hoewel habitatfaktore (veral die intensiteit van dierebemesting) ook 'n rol speel. Die plantgildes wat voorheen vir die eiland opgestel is, toon weinig ooreenkoms met die klasse wat uit hierdie studie na vore kom.

The world's tundra regions can be considered as the last unexploited terrestrial biome on the earth's surface. Bryophytes contribute significantly to primary production and nutrient cycling in tundra habitats but received considerably less attention than the vascular plants during research for the Tundra Biome Project of the International Biological Programme in the 1970s. The IBP synthesis recognised this and called for more bryophyte production data and improved methodology in future studies. The synthesis also identitied the need for more information on within-site variability, energy/chlorophyll relationships and mineral nutrient studies where tundra bryophyte production patterns are concerned. Marion Island in the sub-Antarctic has an oceanic "tundra" type of vegetation, and the island offers the characteristics of an ideal "natural laboratory" for conducting fundamental ecological research particularly in the field of primary production and energy flow. Studies at Marion Island paralleled those of the IBP but also concentrated on the vascular component of the vegetation. Bryophytes contribute up to 60% of the biomass and 90% of plant cover in the mires that dominate the well-vegetated coastal plain of Marion Island. Following the termination of IBP research therefore it was decided to extend these studies during the 1980s by measuring growth and characterising the major factors influencing growth patterns in Marion Island bryophytes. In this thesis information is given on the physical and biotic environment of Marion Island. Data is presented on the cover, biomass, seasonal and annual production values, and turn-over rates (decomposition) of 15 bryophyte species found across the full range of habit at types at Marion Island. An analysis is also made of growth-associated variables viz. soils, climate, plant energy, chlorophyll. water and mineral nutrient contents. Production was found to be related broadly to moisture-related variables, overlain by nutrient factors in some instances. Higher absolute production figures were obtained than at other tundra sites and interesting phenological data are discussed. The results suggest that decomposition is controlled mainly by tissue degradability factors and that decomposition is more significant than production in controlling biomass accumulation. A model is given for production/decomposition patterns across the range of habitat conditions at Marion Island. Several growth measurement techniques were tested and recommendations are made concerning methodology for future bryophyte production studies. By reference to ecological data collected during the study.

Euhedral clinopyroxene mega-crystals have been retrieved from Marion Island, a volcanic island situated on an inactive transform fault near the mid oceanic ridge on Antarctic tectonic plate and part of the Prince Edward Island group. The island is considered to be the product of hotspot- related volcanism. Clinopyroxene megacrysts were sampled from the southern side of the island on a scoria cone named Pyroxene Hill. Several analytical methods including Energy Dispersive Spectrometry (EDS), Electron Probe Microanalysis (EPMA) and EPMA-mapping were utilized in investigating the zoning found within these 5-10 cm large crystals. The zoning found was “patchy”, in that it did not conform to commonly described zoning such as normal, reverse, sector or oscillatory, but rather consisted of chemically distinct areas with either diffuse or sharp boundaries, not orientated parallel to the grain boundaries or crystal lattice. The chemistry of the crystals indicates that they have formed from an evolved basaltic melt, and are likely to have crystallised at a depth of 15- 30 km. A model is postulated for the formation of these crystals in which the megacrysts crystallise rapidly from a supersaturated melt. Pre-existing crystalline material undergoes imperfect diffusion at high temperature to create a patchwork of compositional zones. Supersaturation likely requires a volatile-rich melt, which undergoes rapid degassing owing to an external trigger. The presence of a transform fault directly below Marion Island may provide a seismic trigger for such a degassing event. / Dissertation (MSc)--University of Pretoria, 2013. / Geology / unrestricted

This study focused on the dispersal and dispersion of southern elephant seals, Mirounga leonina, at Marion Island in relation to their natal site, and to their site of first reproduction. Movements from the natal site to terrestrial haulouts used for reproduction, and between successive reproductive sites, were defined as dispersal, while movements from the natal site to sites used for purposes other than reproduction, were defined as dispersion. Some 33000 records collected over 12 years, of haul outs at 54 different sites of 5700 tagged seals, formed the database analysed. Both male and female seals were found to use sites closer to their natal site than expected, for reproductive, moult and winter haulouts. However, breeding seals used sites closer to their site of first reproduction than their natal site, on subsequent reproductive haulouts. No difference was found between the mean distances dispersed to moult sites and to winter haulout sites, but distances of dispersal were significantly less than distances of dispersion. Female seals dispersed further than males to reproductive sites, but no difference between the sexes was apparent for moult and winter dispersion. While the number of male seals hauling out to reproduce was too small to assess the effects of various factors on the dispersal of males, a number of factors influenced the dispersion of male seals, and dispersion and dispersal of female seals. These included age, isolation of natal site, anthropogenic disturbance, natal harem size and natal harem pre-weaning mortality. A number of hypotheses are proposed to explain the reasons behind the results found, and the direction of future research concerning the movements of southern elephant seals and their choice of terrestrial environment is suggested. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / ab2013 / Zoology and Entomology / unrestricted

Marion Island is a sub-Antarctic volcanic island with a cold, wet climate. Much of the interior of the island is bare, with vegetation only found at lower altitudes. No soil classification has yet been undertaken for the Island, and literature on its soils and pedogenesis is sparse. As part of a broader research project on Geomorphology and Climate Change the morphological, physical, chemical, mineralogical and biological properties of soils from seven terrestrial habitats on Marion Island were analysed. It was determined that pedogenesis has taken place on Marion Island. A relationship was observed between soils and terrestrial habitats. Soils were classified according to the World Reference Base (WRB) soil classification system as Histosols, Histic Andosols, Andosols and Regosols. Generalised soil profiles were constructed for each of the seven terrestrial habitats. The spatial distributions of soil types for the Island were predicted with the use of a GIS model and are presented, together with the implications of climate change for pedogenesis and soil distribution on Marion Island. / Dissertation (MSc)--University of Pretoria, 2010. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted