共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
D. J. Marshall N. J. M. Gremmen L. Coetzee B. M. O’Connor P. J. A. Pugh P. D. Theron E. A. Ueckermann 《Polar Biology》1999,21(2):84-89
Sixty species of Acari are recorded from the sub-Antarctic Marion and Prince Edward Islands (the Prince Edward archipelago).
Twenty of the 45 species collected on recent expeditions are new and currently undescribed. Other new taxa include a family
of Mesostigmata, four new genera, and the first sub-Antarctic records of Cillibidae (Mesostigmata) and Eryngiopus (Prostigmata). Fifteen of the 31 species previously reported from the islands are confirmed, although eight of the previous
accounts remain doubtful. The fauna, which shows a distinction between the shoreline and terrestrial components, comprises
endemic, South Indian Ocean Province and sub-Antarctic mite species.
Accepted: 18 July 1998 相似文献
5.
Diatom communities from the sub-Antarctic Prince Edward Islands: diversity and distribution patterns
During an extensive survey of the freshwater and moss-inhabiting diatoms of the Prince Edward Islands, a total of 214 taxa
belonging to 60 genera were found. Three main communities can be found on the two islands. A large part of the samples was
grouped into an aquatic group, bringing together all samples from lentic and lotic waterbodies. A second, contrasting, group
was formed by all dry samples whereas in a third group all habitats with higher mineral contents were found. The habitats
differed clearly in taxa composition reflecting that way possible environmental differences. Although the diatom composition
between the two islands of this island group (Marion and Prince Edward Island) showed some minor qualitative differences,
no marked quantitative differences have been observed. The diatom flora shows a distinct similarity with the other islands
in the southern Indian Ocean, such as the Crozet archipelago and the Kerguelen Islands forming a biogeographical entity in
this part of the ocean, distinctly separated from the non-marine diatom flora in other parts of the (sub-)Antarctic Region. 相似文献
6.
Mesozooplankton surveys were conducted in April/May for fourconsecutive years (19961999) in the vicinity of the PrinceEdward Islands (PEIs), Southern Ocean. The PEIs are locatedin the Polar Frontal Zone, directly in the path of the east-flowingAntarctic Circumpolar Current. Zooplankton were collected byoblique tows using a Bongo net fitted with 300 µm mesh.The abundance, biomass and average size of the mesozooplanktonin the upstream (USR), inter-island (IIR) and downstream (DSR)regions indicated that some groups and species were significantlyaffected by their interaction with the shallow shelf watersof the PEIs. Total mesozooplankton abundance and biomass weretypically highest in the DSR, but no consistent pattern wasevident in the USR and IIR. Copepods, euphausiids and fish weregenerally of a low average size in the IIR. This small sizewas largely attributed to the reduced abundance, or completeabsence, of mesopelagic species from the shelf region. Of totalbiomass, the mesopelagic species Euphausia longirostris, Euphausiasimilis, Pleuromamma abdominalis, Paraeuchaeta biloba and Oncaeaantarctica together contributed an average of 16% to the USR,2% to the IIR and 15% to the DSR. Conversely, epipelagic speciesshowed no consistent pattern of abundance and biomass distributionbetween regions. The low incidence of mesopelagic species overthe island shelf was attributed mainly to reduced advectionof deep water into the shelf region (average depth = 200 m),rather than predation, particularly during the through-flowmode between the islands. This resulted in substantial regionaldifferences in euphausiid community structure. The epipelagicspecies Euphausia vallentini and Thysanoessa vicina completelydominated the IIR, comprising on average 89% of total euphausiidbiomass in this region. However, predation may be importantduring the water-trapping mode between the islands. Advectionof zooplankton into the IIR appeared to be affected by the proximityof the Subantarctic Front (SAF). In 1996, when the SAF was farnorth of the PEIs, reduced current velocities resulted in somedegree of water retention over the shelf and an increased predationimpact. Conversely, when the SAF was close to the PEIs in 1999,more large plankton were transported over the island shelf.High current velocities and productivity associated with theSAF appear to increase the biomass and size of allochthonouszooplankton/nekton advected into the IIR, and consequently mayhave increased the availability of prey to land-based predators.The long-term southward movement of the SAF recently observedin the vicinity of the PEIs may therefore have important implicationsfor the ecosystem of these islands. 相似文献
7.
Roger DeV. Renwick 《American anthropologist》2001,103(2):576-577
Drive Dull Care Away: Folksongs from Prince Edward Island. Edward D. "Sandy" Ives. Charlottetown, P.E.I.: Institute of Island Studies, 1999. 269 pp. 相似文献
8.
9.
A survey was made of the distribution of introduced vascular plants on Marion and Prince Edward Islands. The results of this
survey were compared to results of previous surveys (1965/66, 1975, 1981, 1989). Four new introductions to Marion Island have
taken place, three of which involved species that had been introduced in the past, but had disappeared or were eradicated.
Eighteen species of alien vascular plants are now known from Marion Island. Of these, three were not observed during the present
survey, and another three have been eradicated. Many of the naturalised aliens are still increasing markedly in area and/or
in numbers. Rates of spread of up to 300 m year−1 occur. Three alien vascular species occur on Prince Edward Island. Two are recent introductions, presumably transported to
this island from neighbouring Marion Island by wind or birds.
Accepted: 22 November 1998 相似文献
10.
George M. Branch Colin G. Attwood Dianne Gianakouras Margo L. Branch 《Polar Biology》1993,13(1):23-34
Summary Benthic communities at the sub-Antarctic Prince Edward Islands were sampled qualitatively with an epi-benthic sled at 57 stations over a five year period. Additional information on these communities was obtained from replicate underwater photographs. In total, 546 macrofaunal species were found. Despite the extreme isolation and geological youth of the islands, there seems to have been a diverse colonisation. A cluster-analysis based on species abundance aggregated most stations into 8 groups. Each of these groups had a unique depth and substratum combination. Thourella variabilis (Octocoralea), and Cabarea darwinii (Bryozoa) characterised deep rocky assemblages and Serpula vermicularis, Lanice conchilega (Polychaeta) and Magellania kerguelenensis (Brachiopoda) characterised soft substrata. Indicator species separating each of the 8 clusters are given. Trends in percentage cover and densities of major taxa with respect to depth and substratum, as shown by photographs, are described. Deep, rocky substrata were dominated by Porifera, Bryozoa and Cnidaria, while soft-substrata were dominated by Polychaeta, Bivalvia and Brachiopoda. Errant forms consisted predominantly of Echinodermata, with Crustacea being important in shallower habitats. Filter-feeders dominated the benthos of the islands in all habitats. 相似文献
11.
BACKGROUND: Two of the major risk factors for hepatitis C are injection drug use and receipt of blood or blood products. Many patients are unaware that they have received transfusions. In 1998 Prince Edward Island conducted a province-wide look-back notification program to notify patients who had received transfusions in PEI between Jan. 1, 1984, and June 1, 1990. The authors present the results of the notification program. METHODS: A registry for recipients of blood and blood products was created from the province''s Red Cross blood bank records. The registry data were linked with Vital Statistics data to determine death status and with Health Registration data to determine residence status of recipients (in PEI or moved out of province). All identified recipients with a current PEI mailing address were sent a letter recommending hepatitis C virus (HCV) testing. Laboratory records were checked to determine HCV test results. RESULTS: The registry contained data for 6086 recipients of blood or blood products during the look-back period; 51.1% (3109/6086) had died by the time of notification. Of the remainder, 18.4% (549/2977) were not directly notified because they had moved out of province, had refused delivery of the notification letter or had died recently, or because identifying information was missing from the blood bank records. Of the recipients who were notified 80.4% (1953/2428) underwent testing, and 2.2% (43/1953) were found to be HCV positive. Most of these (58.1% [25/43]) had undergone testing before notification. The HCV positivity rate differed significantly between recipients tested before notification and those tested after notification (9.9% v. 1.1%, p < 0.001). HCV-positive recipients were more likely than other notified recipients to have had multiple transfusions (39.5% v. 9.5%, p < 0.001). INTERPRETATION: Before notification 4.1% of PEI recipients had undergone HCV testing. After notification 91.2% of PEI recipients were identified as tested, dead or moved out of province. The notification program resulted in the identification of the majority of PEI''s transfusion-related cases of hepatitis C. 相似文献
12.
The white-chinned petrel (Procellaria aequinoctialis) is the seabird most often killed on longlines in the Southern Ocean and is listed as vulnerable to extinction. We estimated the population breeding at the Prince Edward Islands, the last breeding site for the nominate subspecies that lacks a recent population estimate. White-chinned petrel burrows are largely confined to deep, muddy soils, usually on slopes below 200?m, but locally up to 420?m. After correcting for count bias, Marion Island has an estimated 29,900 nests (95?% CI 27,700–32,400). Burrow occupancy rates at the start of the incubation period were 65?% during one-off surveys, but repeat surveys found that at least 73?% of burrows were occupied and 87?% of burrows showed signs of occupancy. This suggests that there were roughly 24,000 occupied nests on Marion Island (95?% CI 20,000–28,000). A more cursory survey on Prince Edward Island yielded 14,700 burrows, suggesting that there are 9,000–15,000 occupied nests. The nominate subspecies of white-chinned petrel occupies approximately 974,200 nests (95?% CI 678,000–1,286,000), with the Prince Edward Islands, the third most important breeding site, after South Georgia and Kerguelen. Assuming that populations breeding at islands in the Atlantic and Indian Oceans winter in different regions, the impact of fishery bycatch is likely to have had a greater impact on the Indian Ocean population. The Marion Island survey provides a baseline against which future population changes can be assessed. 相似文献
13.
Climate change and the short-term impact of feral house mice at the sub-Antarctic Prince Edward Islands 总被引:11,自引:0,他引:11
At the Prince Edward Islands, temperatures have increased by approximately 1°C over the past 40 years, accompanied by a decline in precipitation. This has led to a reduction in the peat moisture content of mires and higher growing season warmth. The temperature-and moisture-sensitive sedge, Uncinia compacta R. Br. (Cyperaceae), has consequently increased its aerial cover on Prince Edward Island, but harvesting of seeds by feral house mice (up to 100% removed) has prevented this from happening on Marion Island. Such extensive use of resources suggests that prey switching may be taking place at Marion Island. Scat analyses revealed that mice are·not only eating ectemnorhinine weevils to a greater extent than found in previous studies of populations at Marion Island, but that they also prefer larger weevils (±6 mm). A decrease in body size of preferred weevil prey species [Bothrometopus randi Jeannel and Ectemnorhinus similis C.O. Waterhouse (Coleoptera: Curculionidae)] has taken place on Marion Island (1986–1992), but not on Prince Edward Island. This appears to be a result of increased predation on weevils. In addition, adults of the prey species, E. similis are relatively more abundant on Prince Edward Island than adults of the smaller congener E. marioni Jeannel, and could not be found on Marion Island in the late austral summer of 1991. These results not only provide support for previous hypotheses of the effect of global warming on mouse-plant-invertebrate interactions on the Prince Edward Islands, but also provide limited evidence for the first recorded case of predator-mediated speciation. They also show that the interaction of human-induced changes operating at different scales may have profound consequences for local systems. 相似文献
14.
Sub-Antarctic bottom-dwelling caridean shrimps Nauticaris marionis were collected in April/May between 1984 and 1997 over the shelf region of the Prince Edward Islands (37 °50′E, 46 °45′S).
N. marionis is a partially protandric hermaphrodite. Hatching probably occurs just before April each year, but may persist until May.
During the 1st year N. marionis seem to survive in undetected localities, moult into juveniles, and then settle amongst the benthos from the plankton beginning
probably after November. Diel vertical migration then occurs up to an unknown larger size. The vast majority of juveniles
develop into males, most of which transmutate into females by April/May of their 3rd year. Reproduction can occur before all
male secondary characteristics have been lost. A minority of individuals develop directly into females without passing through
a male phase. Individuals older than 5 years are undetectable using samples of the sizes analysed, but they may well persist
in the population. The von Bertalanffy growth parameters for N. marionis are tentatively identified as k=0.2353/year, L
∞=12.6 mm, t
0=−0.2828 years and WW
∞=2.03 g. Sex-reversal in N. marionis at Marion Island may be affected by the changing environment as sexual differentiation is probably determined during the
planktonic stage.
Accepted: 3 January 2000 相似文献
15.
The collection of maple sap for the production of maple syrup is a large commercial enterprise in Canada and the United States. In Canada, which produces 85% of the world's supply, it has an annual value of over $168 million CAD. Over 38 million trees are tapped annually, 6.5% of which use traditional buckets for sap collection. These buckets attract significant numbers of insects. Despite this, there has been very little investigation of the scale of this phenomenon and the composition of insects that are attracted to this nutrient source. The present paper reports the results of a preliminary study conducted on Prince Edward Island, Canada. Twenty-eight species of Coleoptera, Lepidoptera, and Trichoptera were found in maple sap buckets, 19 of which are known to be attracted to saps and nectars. The physiological role of sap feeding is discussed with reference to moths of the tribe Xylenini, which are active throughout the winter, and are well documented as species that feed on sap flows. Additionally, 18 of the 28 species found in this study are newly recorded in Prince Edward Island. 相似文献
16.
17.
A survey of rubella immunity was conducted among prepubertal girls in Prince Edward Island. Of the 431 girls enrolled in grade 4 in a random sample of schools 83% had a school record of having been vaccinated after their first birthday. A screening test of finger-prick samples revealed that 95% of the girls with a written history of vaccination after their first birthday were immune, 79% of those vaccinated before their first birthday or for whom the date of vaccination was uncertain were immune, and 40% of unvaccinated girls were immune. Of the 49 susceptible girls 43 were vaccinated; all but 2 were found to be immune on retesting. The findings support the recommendation of the National Advisory Committee on Immunization to vaccinate all prepubertal girls without a written history of rubella vaccination after their first birthday. 相似文献
18.
G. C. Grobler L. Janse van Rensburg A. D. S. Bastos C. T. Chimimba S. L. Chown 《Journal of Zoological Systematics and Evolutionary Research》2006,44(3):200-211
There are long‐standing controversies on the taxonomic status of Ectemnorhinus weevil species occurring on the sub‐Antarctic Prince Edward Islands. Since the two islands that constitute the Prince Edward Islands archipelago (PEIA), Marion Island (MI) and Prince Edward Island (PEI), differ in terms of alien invasive species such as the introduced house mouse Mus musculus and conservation management strategies, it is important to consider inter‐island dynamics when investigating inter‐specific relationships. Using a combined molecular phylogenetic and morphometric approach, we attempted to resolve the taxonomic status of the PEIA Ectemnorhinus weevil species. A COI gene phylogeny was inferred following the genetic characterization of 52 Ectemnorhinus weevils from both islands, and morphometric assessment using a set of 15 linear, external measurements was used to differentiate between the two currently recognized species, Ectemnorhinus similis and Ectemnorhinus marioni. Analyses revealed the presence of two genetically and morphometrically distinct species on PEI, whilst evidence for a single species, comprising diverse genetically discrete populations was found on MI. Based on these results, the species unique to PEI has been designated Ectemnorhinus kuscheli n. sp. whilst we confirm the synonymy between E. similis and E. marioni, the two species originally described from MI. E. kuscheli appears to be restricted to PEI, whereas E. similis occurs on both MI and PEI. 相似文献
19.
We report on the first comprehensive collection of invertebrates made on sub-Antarctic Bishop Island, which lies 33 km south
of Macquarie Island. A total of 15 species were collected, of which 14 also occur amongst the 168 species recorded from Macquarie
Island. We hypothesise that the greater species richness of Macquarie Island relative to Bishop Island is largely caused by
the greater habitat diversity on Macquarie Island but that other factors, including accidentally introduced species, may also
be important.
Received: 3 July 1996 / Accepted: 2 October 1996 相似文献
20.
The seasonal dietary composition and estimates of daily consumption rate of Lepidonotothen larseni and Gobionotothen marionensis juveniles were obtained for the first time using fish collected near sub-Antarctic Prince Edward Islands during April 1999–2003. The diet of L. larseni consisted mainly of pelagic prey, with copepods and arrow worms making up the most significant prey groups and accounting for 46% and 40% of prey mass, respectively. The diet of G. marionensis was more diverse than that of L. larseni and was composed mainly of benthic prey, including bottom-dwelling decapods (Nauticaris marionis) and sedentary polychaetes, which accounted for 54% and 30% of prey mass, respectively. During the present study, dietary overlap between juveniles of L. larseni and G. marionensis was very low (<5%) indicating that competition for food resources between them was negligible. They not only relied on different prey species, both also exhibited different diel feeding regimes. Daily consumption rate of L. larseni and G. marionensis juveniles was estimated to be 4.5% and 5.2% of body dry mass, respectively. Stomach contents and stable isotope analyses suggested, that both L. larseni and G. marionensis occupy the forth-trophic level of the sub-Antarctic food web but depend mainly on allochthonous and autochthonous (kelp derived) organic matter, respectively. 相似文献