Log in

Relevant bibliographies by topics / Marion Island / Journal articles

To see the other types of publications on this topic, follow the link: Marion Island.

Journal articles on the topic 'Marion Island'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Marion Island.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Grobler, G. C., A. D. S. Bastos, C. T. Chimimba, and S. L. Chown. "Inter-island dispersal of flightless Bothrometopus huntleyi (Coleoptera: Curculionidae) from the sub-Antarctic Prince Edward Island archipelago." Antarctic Science 23, no. 3 (2011): 225–34. http://dx.doi.org/10.1017/s0954102011000113.

Full text

Abstract:

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

APA, Harvard, Vancouver, ISO, and other styles

2

Bourne, W. R. P. "Marion Island airfield." Marine Pollution Bulletin 18, no. 6 (1987): 262. http://dx.doi.org/10.1016/0025-326x(87)90484-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Bergstrom, Dana M., and V. R. Smith. "Alien vascular flora of Marion and Prince Edward Islands: new species, present distribution and status." Antarctic Science 2, no. 4 (1990): 301–8. http://dx.doi.org/10.1017/s0954102090000426.

Full text

Abstract:

The presence and distribution of alien plant species on subantarctic Marion and Prince Edward Islands is reviewed and updated. This study documents the finding of a well established population of Cerastium fontanum on Prince Edward Island. An additional taxa, Senecio sp., is recorded in association with a recurrence of Plantago lanceolata on Marion Island. Propagules of both these taxa have recently been dispersed to the island in building material imported from South Africa. The distribution of Agrostis stolonifera and Sagina apetala on Marion Island has increased markedly between 1981 and 1989.

APA, Harvard, Vancouver, ISO, and other styles

4

Cerfonteyn, Mia, and Peter G. Ryan. "Have burrowing petrels recovered on Marion Island two decades after cats were eradicated? Evidence from sub-Antarctic skua prey remains." Antarctic Science 28, no. 1 (2015): 51–57. http://dx.doi.org/10.1017/s0954102015000474.

Full text

Abstract:

AbstractIn the 1980s, penguins dominated the prey remains of sub-Antarctic skuas Stercorarius antarcticus breeding on Marion Island, whereas on neighbouring Prince Edward Island burrowing petrels made up >95% of prey remains in nest middens. This difference resulted at least in part from the impact of introduced cats Felis catus on Marion Island’s burrowing petrel populations. Cats were introduced to Marion Island in 1949, and prior to their eradication in 1991, they killed an estimated 450 000 petrels each year, greatly reducing the densities of petrels breeding on the island. A repeat survey of skua prey remains showed that penguins still dominated the prey of breeding sub-Antarctic skuas on Marion Island in the summer of 2010–11, two decades after cats were eradicated from the island. The proportion of penguin remains decreased slightly compared to 1987–88, but this might be expected given the decreases in penguin numbers on Marion Island over this period. Regurgitated pellets confirmed the dominance of penguin prey on Marion Island. Taken together with the decrease in skua numbers on Marion Island over the last two decades, our results suggest that there has been little recovery in the population of at least summer-breeding burrowing petrels since cats were eradicated.

APA, Harvard, Vancouver, ISO, and other styles

5

Hall, Kevin, Ian Meiklejohn, and Adam Bumby. "Marion Island volcanism and glaciation." Antarctic Science 23, no. 2 (2010): 155–63. http://dx.doi.org/10.1017/s0954102010000878.

Full text

Abstract:

AbstractSub-Antarctic Marion Island was the site of extensive volcanism as well as glaciation during both the Quaternary and the Holocene. Initial reconstructions suggested a link between deglaciation and the initiation of faulting which, in turn, facilitated lava eruptions during the interglacials. However, our reassessment of the faulting, volcanic rock, and palaeoglacier distribution indicate that these original interpretations were erroneous. Features thought to be due to faulting are shown to be erosional scarps and this significantly changes interpretations of former glacier distribution. Further, the loss of the former ice cap has revealed new information on former glaciers and their flow directions, thereby allowing reconstruction of palaeoglaciers. Our new reconstruction fits with information from invertebrate genetic mapping that suggest some lava outcrops were nunataks and, therefore, refuges during the Last Glacial period. The new findings of glacial landforms in areas previously covered by snow suggest there was a significant ice advance during the Little Ice Age. Although Holocene volcanic rocks overlie and mask much of the glacial evidence, it has been possible to develop a proposed new reconstruction for glaciation, which is presented together with some of the implications.

APA, Harvard, Vancouver, ISO, and other styles

6

Cooper, John, Nico L. Avenant, and Peter W. Lafite. "Airdrops and king penguins: a potential conservation problem at sub-Antarctic Marion Island." Polar Record 30, no. 175 (1994): 277–82. http://dx.doi.org/10.1017/s0032247400024530.

Full text

Abstract:

ABSTRACTEvidence for the disturbance of king penguins (Aptenodytes patagonicus) and other seabirds at sub-Antarctic islands by fixed-wing aircraft making airdrops is reviewed. Based on direct observations of panicking birds at king penguin colonies at Marion Island as Lockheed C-130 Hercules aircraft flew past, it is postulated that the incident at Macquarie Island in 1990 when many king penguins were found dead shortly after a flypast was most likely caused by panic induced by the aircraft's passage. Visits by fixed-wing aircraft to sub-Antarctic islands should be kept to a minimum and no airstrips should be built on them. Specific recommendations are given for fixed-wing aircraft visits to Marion Island, in order to reduce disturbance to king penguins and other seabirds to the absolute minimum. These recommendations should be adopted at all sub-Antarctic islands.

APA, Harvard, Vancouver, ISO, and other styles

7

Rudolph, E. M., D. W. Hedding, and W. Nel. "The surface geology of the Prince Edward Islands: refined spatial data and call for geoconservation." South African Journal of Geology 124, no. 3 (2021): 627–38. http://dx.doi.org/10.25131/sajg.124.0014.

Full text

Abstract:

Abstract Volcanological maps of the sub-Antarctic Prince Edward Islands were first published in 1968, with a revised surface geology map of Marion Island produced in 2006. These maps have been widely used in terrestrial studies on the Prince Edward Islands but they have limitations in spatial accuracy and detail. Using high-resolution satellite imagery and digital elevation data, more spatially accurate data for both Prince Edward and Marion Island’s surface geology are presented here. In particular, Marion Island’s volcanology on the western coast, including the 1980s lava flow, and the newly exposed Central Highland following the disappearance of extensive ice and snow cover is mapped with greater detail and verified through field observations. The spatial data are downloadable as ESRI layer packages, which can assist in future investigations of island biotic-abiotic processes and interactions and enable improvements in spatial modelling. In addition, this paper highlights geological features and specimens from the Prince Edward Islands as unique examples of geodiversity in a South African context. An overview of these features are provided in terms of their geoheritage value to enable a more comprehensive geoconservation strategy be incorporated into the Prince Edward Islands Management Plan.

APA, Harvard, Vancouver, ISO, and other styles

8

Oosthuizen, W. Chris, P. J. Nico de Bruyn, Mia Wege, and Marthán N. Bester. "Geographic variation in subantarctic fur seal pup growth: linkages with environmental variability and population density." Journal of Mammalogy 97, no. 2 (2015): 347–60. http://dx.doi.org/10.1093/jmammal/gyv181.

Full text

Abstract:

Abstract Marine predator populations are sensitive to temporal variation in prey availability, but prey dynamics are often difficult to quantify. Long-term measures of offspring growth is a useful performance attribute to gauge the potential demographic direction for such predator populations, especially where other metrics (e.g., population size estimates) are lacking. Subantarctic fur seal ( Arctocephalus tropicalis ) females are central place foragers during a protracted lactation period, and their foraging success determines the growth and vitality of their offspring. Using data spanning over 2 decades, we assessed geographic and temporal variation in growth rates and weaning mass of subantarctic fur seal pups at 2 of the species’ principal populations (Gough and Marion islands) and identified environmental conditions that may, through assumed bottom-up mechanisms, affect body mass at weaning. While Marion Island pups grew at an average rate of between 0.040 and 0.067kg/day early in lactation (comparable to conspecific growth at Amsterdam Island), the mean growth rate at Gough Island (approximately 0.030kg/day) was lower than the growth rate represented by the bottom 5% of the body mass distribution at Marion Island. Notwithstanding substantial interannual variability, we found support for a negative trend in weaning mass at both populations, suggesting a rise in limiting factors that is hypothesized to relate to concurrent local population size increases. Weaning mass tended to be higher when sea surface temperatures were warmer (with a stronger positive effect at Gough Island) and during positive phases of the Southern Oscillation Index (La Niña events), with a stronger positive effect in males. Given the low weaning mass of Gough Island fur seal pups, continued population growth here seems unlikely. While density-dependent regulation appears to have increased in strength at Marion Island, terminating rapid population growth, current weaning weights remain above the physiological limits of growth in subantarctic fur seals.

APA, Harvard, Vancouver, ISO, and other styles

9

Mercer, Richard D., A. G. A. Gabriel, J. Barendse, D. J. Marshall, and S. L. Chown. "Invertebrate body sizes from Marion Island." Antarctic Science 13, no. 2 (2001): 135–43. http://dx.doi.org/10.1017/s0954102001000219.

Full text

Abstract:

Body size was measured for 67 of the approximately 120 invertebrate species on Marion Island. These include more than 60% of the 29 acarine families, and more than 80% of the remaining terrestrial invertebrate species. Thus the data are regarded as representative of the entire invertebrate fauna of sub-Antarctic, Marion Island. Length–mass and fresh–dry mass relationships were calculated for orders, families and species to provide a means of estimating body size parameters for species in collections and those which are known from only a few specimens. A comparison of the regression slopes for the different taxonomic ranks indicates that it is better to use regressions from the lowest possible taxonomic level for prediction of body mass. Differences between length–mass relationships for Marion Island insects and continental assemblages raises the question as to the applicability of continental regressions to sub-Antarctic species. This study provides a useful means for estimating body size parameters for Antarctic and sub-Antarctic invertebrates and provides baseline data on an important species trait that seems to be changing with local and global environmental changes.

APA, Harvard, Vancouver, ISO, and other styles

10

Hofmeyr, G. J. G., and M. N. Bester. "Entanglement of pinnipeds at Marion Island." South African Journal of Marine Science 24, no. 1 (2002): 383–86. http://dx.doi.org/10.2989/025776102784528295.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

FRYDAY, Alan M. "New species and combinations in Calvitimela and Tephromela from the southern subpolar region." Lichenologist 43, no. 3 (2011): 225–39. http://dx.doi.org/10.1017/s0024282911000065.

Full text

Abstract:

AbstractThe new species Calvitimela austrochilenis Fryday and Tephromela superba Fryday are described: the former from several collections from southern Chile and one from Marion Island, and the latter from southern South America (including the Falkland Islands), Campbell Island, (New Zealand), and Antarctica. Four new combinations are also made in Tephromela: T. atrocaesia (Nyl. ex Cromb.) Fryday from Îles Kerguelen, Heard Island, South Georgia, and southern South America; T. atroviolacea (Flot.) Fryday from southern South America and Îles Kerguelen; T. lirellina (Darb.) Fryday from only southern South America; and T. skottsbergii (Darb.) Fryday, which is shown to be an earlier name for T. austrolitoralis (Zahlbr.) Kalb & Elix, from throughout the region. Lectotypes are selected for Lecanora atrocaesia and L. atroviolacea. The systematic placement of Tephromela eatonii (Cromb.) Hertel from Kerguelen, Marion Island and Bouvetøya is also discussed but the species is retained in Tephromela.

APA, Harvard, Vancouver, ISO, and other styles

12

Postma, Martin, Marthán N. Bester, and P. J. Nico De Bruyn. "Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method." Antarctic Science 25, no. 6 (2013): 731–40. http://dx.doi.org/10.1017/s0954102013000059.

Full text

Abstract:

AbstractPhysically weighing large marine mammals sequentially over time has presented researchers with a logistical challenge and has severely limited sample sizes. Using a well-established photogrammetry method we developed a simple mathematical method to calculate accurate mass measurements at specific stages in the life cycle of a top marine predator. Female southern elephant seals (n = 23) at Marion Island were sampled sequentially using photogrammetry and three-dimensional models (based on each photogrammetry project) were built for estimation of body mass. Simple equations were applied to obtain mass at critical instances in their life cycle. Marion Island elephant seal mass data was compared to data obtained from physically weighed elephant seals from King George, South Georgia and Macquarie islands. Females from Marion Island are smaller, but their percentage lactation mass loss is similar to females from these other populations. The similarity of percentage mass loss during lactation between different female populations illustrates the accuracy and practicality of the photogrammetric method over a temporal scale. Photogrammetric mass estimation can be used alongside datasets of physically weighed animals and can greatly benefit ecology and life history studies.

APA, Harvard, Vancouver, ISO, and other styles

13

Gittins, Oliver, Llorenç Grau-Roma, Rosa Valle, et al. "Serological and molecular surveys of influenza A viruses in Antarctic and sub-Antarctic wild birds." Antarctic Science 32, no. 1 (2019): 15–20. http://dx.doi.org/10.1017/s0954102019000464.

Full text

Abstract:

AbstractTo evaluate how avian influenza virus (AIV) circulates among the avifauna of the Antarctic and sub-Antarctic islands, we surveyed 14 species of birds from Marion, Livingston and Gough islands. A competitive enzyme-linked immunosorbent assay was carried out on the sera of 147 birds. Quantitative reverse transcription polymerase chain reaction was used to detect the AIV genome from 113 oropharyngeal and 122 cloacal swabs from these birds. The overall seroprevalence to AIV infection was 4.8%, with the only positive results coming from brown skuas (Catharacta antarctica) (4 out of 18, 22%) and southern giant petrels (Macronectes giganteus) (3 out of 24, 13%). Avian influenza virus antibodies were detected in birds sampled from Marion and Gough islands, with a higher seroprevalence on Marion Island (P = 0.014) and a risk ratio of 11.29 (95% confidence interval: 1.40–91.28) compared to Gough Island. The AIV genome was not detected in any of the birds sampled. These results confirm that AIV strains are uncommon among Antarctic and sub-Antarctic predatory seabirds, but they may suggest that scavenging seabirds are the main avian reservoirs and spreaders of this virus in the Southern Ocean. Further studies are necessary to determine the precise role of these species in the epidemiology of AIV.

APA, Harvard, Vancouver, ISO, and other styles

14

Miya, Tshoanelo, Ofer Gon, Monica Mwale, and C. H. Christina Cheng. "Multiple independent reduction or loss of antifreeze trait in low Antarctic and sub-Antarctic notothenioid fishes." Antarctic Science 28, no. 1 (2015): 17–28. http://dx.doi.org/10.1017/s0954102015000413.

Full text

Abstract:

AbstractAntifreeze glycoprotein (AFGP) in Antarctic notothenioids presumably evolved once at the base of the notothenioid radiation in the Southern Ocean. Some species closely related to the endemic Antarctic notothenioids occur in non-freezing sub-Antarctic waters where antifreeze protection is unnecessary. We examined the antifreeze trait (phenotype and genotype) of these sub-Antarctic species to help infer their evolutionary history and origin. The status of the AFGP genotype (AFGP coding sequences in DNA) and/or phenotype (serum thermal hysteresis) varies widely, from being undetectable in Dissostichus eleginoides and Patagonotothen species from the Falkland Islands, minimal in Marion Island Paranotothenia magellanica and Lepidonotothen squamifrons from the South Sandwich and Bouvet islands, to considerable genotype in the Falkland Islands Champsocephalus esox and Marion Island Harpagifer georgianus. All low Antarctic notothenioid species examined show substantial AFGP trait. Mapping of the AFGP trait status onto ND2 phylogenetic trees of a large sampling of notothenioids revealed that AFGP trait reduction or loss occurred at least three independent times in different lineages.

APA, Harvard, Vancouver, ISO, and other styles

15

Abad, F. Xavier, Núria Busquets, Azucena Sanchez, Peter G. Ryan, Natàlia Majó, and Jacob Gonzalez-Solís. "Serological and virological surveys of the influenza A viruses in Antarctic and sub-Antarctic penguins." Antarctic Science 25, no. 2 (2013): 339–44. http://dx.doi.org/10.1017/s0954102012001228.

Full text

Abstract:

AbstractTo evaluate the avian influenza virus (AIV) circulation in Antarctic and sub-Antarctic penguins we carried out a serosurvey on six species from Livingston, Marion and Gough islands. Seropositivity against AIV was performed on serum samples using a competitive enzyme-linked immunosorbent assay and haemagglutination and neuraminidase inhibition assays. Some oropharyngeal and cloacal swabs were also assayed to detect influenza virus genomes by real time reverse transcription-polymerase chain reaction. Overall, 12.1% (n= 140) penguins were seropositive to AIV. By species, we detected 5% (n= 19) and 11% (n= 18) seroprevalence in sub-Antarctic rockhopper penguins (Eudyptesspp.) from Gough and Marion islands, respectively, 42% (n= 33) seroprevalence in macaroni penguins (Eudyptes chysolophusBrandt), but no positives in the three other species, gentoo (Pygoscelis papuaForster;n= 25) and chinstrap penguins (P. antarcticaForster;n= 16), from Livingston Island and king penguins (Aptenodytes patagonicusMiller;n= 27) from Marion Island. While seropositivity reflected previous exposure to the AIV, the influenza genome was not detected. Our results indicate that AIV strains have circulated in penguin species in the sub-Antarctic region, but further studies are necessary to determine the precise role that such penguin species play in AIV epidemiology and if this circulation is species (or genus) specific.

APA, Harvard, Vancouver, ISO, and other styles

16

Dartnall, Herbert J. G., and Valdon R. Smith. "Freshwater Invertebrates of Sub-Antarctic Marion Island." African Zoology 47, no. 2 (2012): 203–15. http://dx.doi.org/10.3377/004.047.0207.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Dartnall, Herbert J. G., and Valdon R. Smith. "Freshwater invertebrates of sub-Antarctic Marion Island." African Zoology 47, no. 2 (2012): 203–15. http://dx.doi.org/10.1080/15627020.2012.11407548.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

RAND, R. W. "NOTES ON THE MARION ISLAND FUR SEAL." Proceedings of the Zoological Society of London 126, no. 1 (2009): 65–82. http://dx.doi.org/10.1111/j.1096-3642.1956.tb00425.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

RAND., R. W. "NOTES ON THE BIRDS OF MARION ISLAND." Ibis 96, no. 2 (2008): 173–206. http://dx.doi.org/10.1111/j.1474-919x.1954.tb04125.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Bester, Marthán N., Hendrik de Clercq, G. J. Greg Hofmeyr, and P. J. Nico de Bruyn. "Leucistic southern elephant seal at Marion Island?" Polar Biology 31, no. 2 (2007): 255–57. http://dx.doi.org/10.1007/s00300-007-0380-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Reisinger, Ryan R., N. Thomas Mufanadzo, P. J. Nico de Bruyn, and Marthán N. Bester. "Leucistic southern elephant seal at Marion Island." Polar Biology 32, no. 3 (2009): 509–11. http://dx.doi.org/10.1007/s00300-008-0572-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Sumner, P. D. "Rock Weathering Rates on Subantarctic Marion Island." Arctic, Antarctic, and Alpine Research 36, no. 1 (2004): 123–27. http://dx.doi.org/10.1657/1523-0430(2004)036[0123:rwrosm]2.0.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Philip, L., Z. Abdurashidova, H. C. Chiang, et al. "Probing Radio Intensity at High-Z from Marion: 2017 Instrument." Journal of Astronomical Instrumentation 08, no. 02 (2019): 1950004. http://dx.doi.org/10.1142/s2251171719500041.

Full text

Abstract:

We introduce Probing Radio Intensity at high-Z from Marion (PRIZM), a new experiment designed to measure the globally averaged sky brightness, including the expected redshifted 21[Formula: see text]cm neutral hydrogen absorption feature arising from the formation of the first stars. PRIZM consists of two dual-polarization antennas operating at central frequencies of 70 and 100[Formula: see text]MHz, and the experiment is located on Marion Island in the sub-Antarctic. We describe the initial design and configuration of the PRIZM instrument that was installed in 2017, and we present preliminary data that demonstrate that Marion Island offers an exceptionally clean observing environment, with essentially no visible contamination within the FM band.

APA, Harvard, Vancouver, ISO, and other styles

24

Schoombie, S., J. Schoombie, A. Oosthuizen, et al. "Avian pox in seabirds on Marion Island, southern Indian Ocean." Antarctic Science 30, no. 1 (2017): 3–12. http://dx.doi.org/10.1017/s0954102017000347.

Full text

Abstract:

AbstractAlbatrosses are among the most threatened groups of seabirds with the main land-based threats being alien invasive species, human disturbance and habitat degradation. Disease outbreaks in Antarctic and sub-Antarctic seabird populations are uncommon, but in the past few decades there has been an increase in reported cases. The sub-Antarctic Prince Edward Islands (46°S, 37°E) in the south-western Indian Ocean provide breeding grounds for many seabird species, including 44% of all wandering albatrosses (Diomedea exulans L.). In 2015, five wandering albatrosses and two penguins (Eudyptes chrysocome Forster and Aptenodytes patagonicus Miller) with pox-like lesions were observed on Marion Island, the larger of the two Prince Edward Islands. Despite intensive study of the wandering albatross population since the 1980s, the only previous records of such lesions are one case in 2006 and another in 2009 in white-chinned petrels (Procellaria aequinoctialis L.). Molecular and phylogenetic analysis of tissue samples from two albatross chicks confirmed the presence of avian pox virus (Avipoxvirus). This highlights the need for research into the diseases present on sub-Antarctic islands, for strict controls to limit the risk of accidental introduction of diseases through human activities and the need for effective conservation measures in the event of an outbreak.

APA, Harvard, Vancouver, ISO, and other styles

25

Mortimer, Elizabeth, Melodie A. McGeoch, Savel R. Daniels, and Bettine Jansen van Vuuren. "Growth form and population genetic structure ofAzorella selagoon sub-Antarctic Marion Island." Antarctic Science 20, no. 4 (2008): 381–90. http://dx.doi.org/10.1017/s0954102008001004.

Full text

Abstract:

AbstractSeven community complexes have been described across sub-Antarctic Marion Island, amongst these fellfield that comprise low plant cover dominated byAzorella selagoHook. f.Azorellais considered a keystone species since it forms nutrient rich environments for microarthropod communities and epiphytic plants. Two distinct growth forms typifyAzorella, namely discrete cushions and continuous mats. Whether these continuous mats normally consist of a single large cushion individual, or whether several individual plants merge, interdigitating to form a continuous area, remains unclear. As such, it is important to obtain some measure ofAzorellagrowth dynamics before embarking on phylogeographic studies. Previous genetic studies indicated that several microarthropod species are significantly substructured across Marion Island, but it remains unclear whether similar subdivisions characterizeAzorella. We used chloroplast sequence data (trnH-psbA) and amplified fragment length polymorphism (AFLP) to investigate these questions. No sequence variation characterized thetrnH-psbA region inAzorellaacross Marion Island. In contrast, the AFLP results indicated that anA. selagomat comprises multiple individuals. We argue that mats can be formed through at least two processes namely fragmentation, where parts of the cushion plant die off creating open areas for the establishment of different individuals and/or high density of interdigitating individuals merging to form the mat. Fragment data further indicated significant substructure forAzorellaacross Marion Island (FST = 0.101,P = 0.01) and we attribute this to past vicariance.

APA, Harvard, Vancouver, ISO, and other styles

26

Smith, V. R. "Terrestrial slug recorded from sub-Antarctic Marion Island." Journal of Molluscan Studies 58, no. 1 (1992): 80–81. http://dx.doi.org/10.1093/mollus/58.1.80.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

McDOUGALL, IAN, WILHELM VERWOERD, and LUC CHEVALLIER. "K–Ar geochronology of Marion Island, Southern Ocean." Geological Magazine 138, no. 1 (2001): 1–17. http://dx.doi.org/10.1017/s0016756801005039.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Plessis, C. J. du, Y. M. van Heezik, and P. J. Seddon. "Timing of King Penguin Breeding at Marion Island." Emu - Austral Ornithology 94, no. 3 (1994): 216–19. http://dx.doi.org/10.1071/mu9940216.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Holness, Stephen Dale. "Sorted circles in the maritime Subantarctic, Marion Island." Earth Surface Processes and Landforms 28, no. 4 (2003): 337–47. http://dx.doi.org/10.1002/esp.430.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Rudolph, Elizabeth M., David W. Hedding, and Werner Nel. "The glacial geomorphology of sub-Antarctic Marion Island." Journal of Maps 17, no. 2 (2021): 313–24. http://dx.doi.org/10.1080/17445647.2021.1931970.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Hugo-Coetzee, Elizabeth A., and Peter C. Le Roux. "Distribution of microarthropods across altitude and aspect in the sub-Antarctic: climate change implications for an isolated oceanic island." Acarologia 58, Suppl (2018): 43–60. http://dx.doi.org/10.24349/acarologia/20184278.

Full text

Abstract:

Current climate change is altering the distribution of species across both broad and fine scales. Examining contemporary species distributions along altitudinal gradients is one approach to predicting species future distributions, as species occurrence patterns at cold, high altitudes are expected to resemble the species distribution patterns currently observed at warmer, lower altitudes if warming occurs. Strong changes in climate have been observed in the sub-Antarctic over the last 50 years, with a 1.5 °C increase in mean temperature and a c. 30% decrease in mean precipitation recorded on Marion Island. In this study, the distribution patterns of mites and springtails inhabiting the cushion-plant Azorella selago were studied on Marion Island. Mite and springtail species richness and springtail abundance were significantly higher on the western aspect of the island, possibly due to higher rainfall and greater cloud cover on the windward side of the island. Mite abundance did not differ between aspects of the island, which may be due to the higher desiccation tolerance of mites. Mite and springtail species richness and springtail abundance were significantly lower at high altitudes coinciding with lower temperatures and generally harsher environment at higher altitudes. Plant characteristics generally did not contribute to explaining species patterns, suggesting that at the island-scale abiotic variables, rather than biotic factors, appeared to be the more important determinants of community structure. Therefore, despite species responding individualistically, it is clear that a warmer and drier climate will dramatically change the microarthropod community structure within A. selago on Marion Island.

APA, Harvard, Vancouver, ISO, and other styles

32

Jonker, F. C., and M. N. Bester. "Seasonal movements and foraging areas of adult southern female elephant seals, Mirounga leonina, from Marion Island." Antarctic Science 10, no. 1 (1998): 21–30. http://dx.doi.org/10.1017/s0954102098000042.

Full text

Abstract:

Seasonal movements and foraging areas of postbreeding (n = 9) and postmoulting (n = 3) adult southern elephant seal females from Marion Island were studied using Geolocation Time-depth Recorders. Movements were classified into three phases – an outbound transit phase, distant foraging phase, and an inbound transit phase. The longest residence time of postbreeding females during their foraging migrations was in areas at the outer edge of their feeding range (± 1460 km) both to the north and south of the island, largely within inter-frontal zones south of the Antarctic Polar Front (APF) and between the Sub-Tropical Convergence (STC) and the Sub-Antarctic Front (SAF). Postmoulting females travelled further afield (2122–3133 km distant) to the APF, to inter-frontal zones south of the APF (within the pack ice outer edge), as well as to the Antarctic Continental Shelf. This study provides additional information on the putative function of dive types in relation to the movement phases of elephant seal females from Marion Island. The relative frequency of assumed ‘foraging’, ‘exploratory’ and ‘transit’ dive types, as well as the duration and location of the different phases of movement suggest two seasonal foraging strategies. Sea floor topography could possibly cue the transit phases of both postbreeding and postmoulting females from Marion Island.

APA, Harvard, Vancouver, ISO, and other styles

33

Mcintyre, Trevor, Horst Bornemann, Joachim Plötz, Cheryl A. Tosh, and Marthán N. Bester. "Deep divers in even deeper seas: habitat use of male southern elephant seals from Marion Island." Antarctic Science 24, no. 6 (2012): 561–70. http://dx.doi.org/10.1017/s0954102012000570.

Full text

Abstract:

AbstractWe describe the habitat use of 22 male southern elephant seals (Mirounga leonina) satellite tagged at Marion Island between 2004 and 2008. While a few areas of increased utilization appeared to be associated with areas of shallower bathymetry (such as sea-floor ridges and fracture zones), seals in our study did not target other areas of shallow bathymetry within close proximity to Marion Island. Rather, most elephant seals foraged pelagically over very deep water where much variation was evident in diel vertical migration strategies. These strategies resulted in generally deeper and longer dives than what has been reported for male elephant seals from other colonies. No significant differences were recorded for dive durations or dive depths between adults and sub-adults. However, younger animals displayed a positive relationship between dive durations and age, as well as between dive depths and age, while these relationships became negative for older animals. Mixed model outputs suggested that seals increased their aerobic fitness as migrations progressed, enabling them to undertake longer dives. We conclude that Marion Island male elephant seals exhibit much variability in dive strategy and are seemingly capable of exploiting a range of different prey types occurring in various depth layers.

APA, Harvard, Vancouver, ISO, and other styles

34

Cooper, J., J. E. Crafford, and T. Hecht. "Introduction and extinction of brown trout (Salmo trutta L.) in an impoverished subantarctic stream." Antarctic Science 4, no. 1 (1992): 9–14. http://dx.doi.org/10.1017/s095410209200004x.

Full text

Abstract:

Brown trout were introduced to the Van den Boogaard River on subantarctic Marion Island in 1964, and a small population became established. The last individual was seen in 1984, and the species is now considered to be extinct on the island. Their diet was exclusively allochthonous, with snails and spiders predominating. Ages estimated at six to eleven years showed that spawning must have occurred since the original introduction. Since the Van den Boogaard River enters the sea via a waterfall, it is postulated that trout were not able to practice an anadromous life-style, and that this, as well as other factors connected with the impoverished nature of the stream, led to dwarfing of the resident population. No further introductions of alien fish to Marion Island should be contemplated.

APA, Harvard, Vancouver, ISO, and other styles

35

Váňa, Jiří. "Pseudoisotachis Pocsii Váňa, A New Genus and Species of Liverwort from the Subantarctic Marion Island." Polish Botanical Journal 58, no. 1 (2013): 55–58. http://dx.doi.org/10.2478/pbj-2013-0006.

Full text

Abstract:

AbstractA new genus and new species of liverwort, Pseudoisotachis Váňa and Pseudoisotachis pocsii Váňa, is described from Marion Island, part of the Prince Edward Islands, a subantarctic archipelago situated in the Kerguelen Province of the southern Indian Ocean. Family placement of the new genus and species is uncertain due to absence of androecia, gynoecia and sporophytes; morphologically it is compared with some genera of Isotachidaceae and with the genus Orthocaulis of Anastrophyllaceae. The new species is described and illustrated.

APA, Harvard, Vancouver, ISO, and other styles

36

Reisinger, RR, PJN de Bruyn, and MN Bester. "Abundance estimates of killer whales at subantarctic Marion Island." Aquatic Biology 12, no. 2 (2011): 177–85. http://dx.doi.org/10.3354/ab00340.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Henssen, Aino. "EDW Ardiella Mirabilis, A Holocarpous Lichen from Marion Island." Lichenologist 18, no. 1 (1986): 51–56. http://dx.doi.org/10.1017/s0024282986000063.

Full text

Abstract:

AbstractThe new genus Edwardiella Henssen with the single species E. mirabilis Henssen is described in the Lichinaceae to include a holocarpous lichen. Colonies of the Gloeocapsa-phycobiont which are invaded by the fungal hyphae develop directly into apothecia or pycnidia. The apothecia are thallinocarps. The lichen was collected in the subantarctic Marion Island where it was mainly growing in lichenized tufts of Scytonema. Two new combinations, Gonohymenia nigritella (Lettau) Henssen and G. hondoana (Zahlbr.) Henssen are made.

APA, Harvard, Vancouver, ISO, and other styles

38

Smith, V. R. "Chemical composition of precipitation at Marion Island (sub-Antarctic)." Atmospheric Environment (1967) 21, no. 5 (1987): 1159–65. http://dx.doi.org/10.1016/0004-6981(87)90243-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Keith, M., M. N. Bester, P. A. Bartlett, and D. Baker. "Killer whales (Orcinus orca) at Marion Island, Southern Ocean." African Zoology 36, no. 2 (2001): 163–75. http://dx.doi.org/10.1080/15627020.2001.11657134.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Barendse, J., R. D. Mercer, D. J. Marshall, and S. L. Chown. "Habitat Specificity of Mites on Sub-Antarctic Marion Island." Environmental Entomology 31, no. 4 (2002): 612–25. http://dx.doi.org/10.1603/0046-225x-31.4.612.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Gaston, K. J., S. L. Chown, and R. D. Mercer. "The animal species-body size distribution of Marion Island." Proceedings of the National Academy of Sciences 98, no. 25 (2001): 14493–96. http://dx.doi.org/10.1073/pnas.251332098.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Jones, M. Genevieve W., Ben J. Dilley, Quentin A. Hagens, et al. "Wandering Albatross Diomedea exulans breeding phenology at Marion Island." Polar Biology 40, no. 5 (2016): 1139–48. http://dx.doi.org/10.1007/s00300-016-2042-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Pistorius, Pierre, Marthán Bester, Stephen Kirkman, and Frances Taylor. "Pup mortality in southern elephant seals at Marion Island." Polar Biology 24, no. 11 (2001): 828–31. http://dx.doi.org/10.1007/s003000100285.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

de Bruyn, P. J. Nico, Pierre A. Pistorius, Cheryl A. Tosh, and Marthán N. Bester. "Leucistic Antarctic fur seal Arctocephalus gazella at Marion Island." Polar Biology 30, no. 10 (2007): 1355–58. http://dx.doi.org/10.1007/s00300-007-0320-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Reisinger, Ryan R., P. J. Nico de Bruyn, Pierre A. Pistorius, and Marthán N. Bester. "Antarctic fur seal predation on cephalopods at Marion Island." Polar Biology 33, no. 4 (2009): 571–74. http://dx.doi.org/10.1007/s00300-009-0731-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Smith, Valdon R. "Energy flow and nutrient cycling in the Marion Island terrestrial ecosystem: 30 years on." Polar Record 44, no. 3 (2008): 211–26. http://dx.doi.org/10.1017/s0032247407007218.

Full text

Abstract:

ABSTRACTThis article is a sequel to a word-model description of the ecosystem of sub-Antarctic Marion Island, published in this journal 30 years ago (Smith 1977). It expands on the qualitative considerations of patterns of energy flow and nutrient cycling presented in that paper, by providing quantitative information from subsequent research at the island. Primary production of the island's lowland plant communities is high on an annual basis, because the vegetation has a long growing season due to the lack of severely cold winters or drought. Daily productivity is actually low due to low radiation levels and a cool growing season. The vegetation is particularly efficient regarding its use of nutrients for its growth, but still requires substantial amounts of nutrients to support the high annual production. Seabirds and seals import large quantities of nutrients from the ocean when they breed and moult on the island. They markedly enhance soil and plant nutrient status in the areas in which they occur, and also in adjacent areas. However, by far the greater part of the island's inland vegetation is not directly influenced by birds or seals and most of the nutrients required for plant growth are provided by decomposition of plant litter and peat. Soil invertebrates are crucial facilitators of decomposition processes, which are otherwise restricted by low soil temperatures and high soil moisture contents. Introduced house mice have invaded almost all parts of the island and predate heavily on the invertebrates, thus affecting nutrient mineralisation. This threatens not only the functioning (lowered nutrient availability leading to slower plant growth and the production of a lower quality, more decomposition-recalcitrant plant litter), but also the structure (an altered balance between production and decomposition leads to a change in the relation between peat formation and degradation, which is an important determinant of vegetation succession) of the island's ecosystem. It is suggested that mice may also affect the island's ecology by predating on seabird chicks.

APA, Harvard, Vancouver, ISO, and other styles

47

Pistorius, P. A., M. N. Bester, and S. P. Kirkman. "Dynamic age-distributions in a declining population of southern elephant seals." Antarctic Science 11, no. 4 (1999): 445–50. http://dx.doi.org/10.1017/s0954102099000577.

Full text

Abstract:

Estimates of births and standing age-distributions were combined to estimate the size of the southern elephant seal population at Marion Island at various times during its decline. To estimate births each year from 1986 through 1997 we used the number of adult females hauled out on 15 October, which is the peak haulout date for breeding elephant seal females at all breeding sites in the Indian Ocean. A conversion factor (3.15) was derived from the standing age-distributions, and applied to estimates of annual births to yield total population size. The population at Marion Island declined 37.5% overall from 1986–97 at an annual rate of 4.3% from 1986–91 and c. 2.5% yr−1 afterwards.

APA, Harvard, Vancouver, ISO, and other styles

48

Phiri, Ethel E., Melodie A. McGeoch, and Steven L. Chown. "Spatial variation in structural damage to a keystone plant species in the sub-Antarctic: interactions betweenAzorella selagoand invasive house mice." Antarctic Science 21, no. 3 (2008): 189–96. http://dx.doi.org/10.1017/s0954102008001569.

Full text

Abstract:

AbstractOn Southern Ocean islands the effects of the house mouse on plants are not well understood. In particular, its influence at the landscape scale has largely been overlooked. To address this issue, we systematically mapped the distribution of a keystone, cushion plant species,Azorella selago, and mouse damage to it across Marion Island. Mouse damage was observed in a third of the sampled sites from sea level to 548 m a.s.l. Damage to individual cushions ranged from single burrows to the disintegration of entire cushions. Mouse damage was high in sites with lowA. selagodensity, suggesting that in areas of low cushion density the impact of mice may be substantial. Moreover, it is not simply direct impacts on theA. selagopopulation that are ecologically significant.Azorella selagocushions serve as nurse plants for many epiphyte species, so increasing the altitudinal range of a variety of them, and also house high densities of invertebrates especially in fellfield landscapes. In consequence, this study demonstrates that mice are having a significant, negative impact at the landscape scale on Marion Island, so adding to the growing list of species and ecosystem-level effects attributable to this invasive rodent.

APA, Harvard, Vancouver, ISO, and other styles

49

Bester, Marthán N., and Peter A. Bartlett. "Attendance behaviour of Antarctic and subantarctic fur seal females at Marion Island." Antarctic Science 2, no. 4 (1990): 309–12. http://dx.doi.org/10.1017/s0954102090000438.

Full text

Abstract:

The female attendance behaviour of Antarctic fur seals (Arctocephalus gazella) and subantarctic fur seals (A.tropicalis), which breed sympatrically on subantarctic Marion Island, was investigated. Over the same period after the breeding season, the mean duration of feeding trips to sea, and percentage of time spent at sea, did not differ significantly between lactating females of the two species. The difference in mean duration of shore visits was significant and the longer onshore attendance of A. tropicalis probably related to the lower demand by their pups which grow at a slower rate. The subpolar maternal adaptations of A. gazella were unchanged under the more temperate environment at Marion Island, and it remains to be established unequivocally whether conditions there are limiting to the species.

APA, Harvard, Vancouver, ISO, and other styles

50

Hofmeyr, G., Maine M. De, Mr Beste, S. Kirkman, P. Pistorius, and A. Makhado. "Entanglement Of Pinnipeds At Marion Island, Southern Ocean: 1991-2001." Australian Mammalogy 24, no. 1 (2002): 141. http://dx.doi.org/10.1071/am02141.

Full text

Abstract:

Some 101 fur seals Arctocephalus spp. and five southern elephant seals Mirounga leonina were recorded entangled in anthropogenic debris over ten years at Marion Island, Southern Ocean. Approximately 67% of materials causing entanglement originated in the fishing industry. Polypropylene packaging straps were the most common entangling material, followed by trawl netting. Longline hooks embedded in animals, fishing line and portions of plastic were only encountered after the inception in 1996 of longline fishing in the waters around Marion Island. The incidence of entanglement of Arctocephalus spp. during the 1996-2001 longline fisheries period increased by more than 50% over that of the 1991-1996 pre-longline fisheries period. An estimated 0.24% of the populations of fur seals were entangled. The numbers of entangled M. leonina are very low. Longline fishing has had a direct, albeit small, impact on the pinniped populations

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!