Authors:Alejandro Velasco-Castrillón; Ian Hawes, Mark I. Stevens Pages: 209 - 219 Abstract: Over a century ago microfaunal diversity was first recorded by James Murray in lakes at Cape Royds, Ross Island, Antarctica. The report stands as the seminal study for today’s biodiversity investigations, and as a baseline to evaluate changes in faunal communities and introductions. In the present study, Cape Royds lakes were revisited and the mitochondrial c oxidase subunit I (COI) gene and morphology were used to compare diversity of Rotifera, Tardigrada and Nematoda with the records Murray published in the early 1900s. Cyanobacterial mats and the water column were sampled for microfauna from the five largest lakes using methods described by Murray. Across all five lakes similar patterns were observed for species distribution of all three phyla reported by Murray over 100 years ago. Some changes in species assemblages were identified within and between lakes, but there were no new introductions of named species for the Cape Royds region. Some of the species included by Murray in his monograph have been recently redescribed as Antarctic endemics, but others still retain their original name from the Northern Hemisphere holotypes and are also in need of revision to adequately determine the true endemism for these faunal groups. PubDate: 2018-08-01T00:00:00.000Z DOI: 10.1017/S095410201800007X Issue No:Vol. 30, No. 4 (2018)
Authors:Maria V. Petry; Fernanda C.L. Valls, Elisa S. Petersen, Júlia V.G. Finger, Lucas Krüger Pages: 220 - 226 Abstract: Available information about seabird breeding population trends on Stinker Point (Elephant Island, Maritime Antarctic Peninsula) is outdated by decades. This study reports current numbers of breeding species, and evaluates population trends over 28 years. We counted breeding pairs of seabirds along all ice-free areas on Stinker Point during two distinct periods (summers of 1985/86–1991/92 and 2009/10–2013/14). Thirteen species currently breed in the area: four Sphenisciformes, four Procellariiformes, one Suliforme and four Charadriiformes. Chinstrap penguin Pygoscelis antarcticus has the highest number of breeding pairs (4971±590), followed by gentoo penguin Pygoscelis papua (1242±339). Comparisons between the two intervals showed declining trends for almost all breeding populations, although southern giant petrels Macronectes giganteus are experiencing a subtle population growth. Population decreases in locations with low human disturbance, such as Stinker Point, may indicate sensibility to climate and environmental change and need further investigation. PubDate: 2018-08-01T00:00:00.000Z DOI: 10.1017/S0954102018000135 Issue No:Vol. 30, No. 4 (2018)
Authors:Shaun T. Brooks; Julia Jabour, Dana M. Bergstrom Pages: 227 - 235 Abstract: Footprint has become a common term in environmental research in Antarctica, yet after 25 years there is still no certainty about what it refers to. In relation to Antarctica, the closest definition has been ‘the spatial extent and intensity of disturbance’. Yet there is still confusion around what a ‘disturbance’ footprint is actually measuring. This is evident within Committee for Environmental Protection documents, in which there have been over 80 mentions of footprint, with at least eight different meanings, since 1998. To improve clarity in its use by both scientists and policymakers, we first examine the development of the term footprint, how it has been applied, and its usefulness in applications such as interpreting ‘minor or transitory’ activities. We then identify and define a suite of footprint types (disturbance, building, contamination, non-native species, noise, visual, visitation, risk, carbon, ecological, and human), with the aim of developing a common understanding of what the term refers to. Our goal is to ensure the concept of footprint can be a useful environmental tool to facilitate progressing environmental protection. PubDate: 2018-08-01T00:00:00.000Z DOI: 10.1017/S0954102018000172 Issue No:Vol. 30, No. 4 (2018)
Authors:Henri Weimerskirch; Fabrice Le Bouard, Peter G. Ryan, C.A. Bost Pages: 236 - 242 Abstract: King penguins (Aptenodytes patagonicus Miller) are major consumers in the Southern Ocean. The colony at Ile aux Cochons, Iles Crozet, in the southern Indian Ocean was known in the 1980s as the largest king penguin colony and the second largest penguin colony in the world. However, there have not been any recent estimates of this colony. Aerial photographs taken from a helicopter, and satellite images were used to report on changes in the colony and population sizes over the past 50 years. The colony has declined by 88% over the past 35 years, from c. 500 000 pairs to 60 000 pairs. The possible causes of this decline were explored but no plausible explanation for such an unprecedented decrease in penguin populations was found. The study highlights the use of satellite imagery as a non-invasive technique for population monitoring, and stresses the need for further research on the causes of this alarming trend in this colony. PubDate: 2018-08-01T00:00:00.000Z DOI: 10.1017/S0954102018000226 Issue No:Vol. 30, No. 4 (2018)
Authors:Young-Hwan G. Kim; Jusun Woo, Tae-Yoon S. Park, Ji-Hoon Kihm, Jong Ik Lee, Moon Young Choe Pages: 245 - 263 Abstract: The submarine channel-fill system of the Cambrian Spurs Formation exhibits unique metre-scale cycles of breccia and diamictite. The studied sections, Eureka Spurs, are located at the Mariner Glacier in the central-eastern part of northern Victoria Land, Antarctica. A facies analysis of the channel-fill deposit has led to the recognition of four main lithofacies: breccia, diamictite, thin-bedded sandstone and mudstone. The channel-fill deposit consists of two architectural elements: hollow-fill (HF) and sheet-like (SL) elements. The SL has wide convex-up geometry and consists solely of a very thick bed of diamictite, and is interpreted as a submarine channel lobe. The HF has a concave-up erosional base and flat upper surface. The HF consists of nine cyclic alternations of underlying breccia (cohesionless debris flow) and overlying diamictite (cohesive debris flow). The deposition of breccia is interpreted to have been controlled by repeated allogenic processes such as earthquakes. In contrast, the abrupt vertical transition from breccia to diamictite in each cycle is interpreted to have resulted from an autogenic, slope instability-related process. The interaction of the allogenic and autogenic factors recorded in the metre-scale unique cyclic deposits provides new criteria to interpret cycles of submarine debris flow. PubDate: 2018-08-01T00:00:00.000Z DOI: 10.1017/S0954102018000123 Issue No:Vol. 30, No. 4 (2018)
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