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671.
S Schoombie RJM Crawford AB Makhado BM Dyer PG Ryan 《African Journal of Marine Science》2016,38(1):119-127
Sub-Antarctic Marion Island is one of the few islands where both species of Phoebetria albatrosses breed sympatrically. The last published assessment of their population trends, which reported counts up to 2008, concluded that the numbers of breeding pairs of sooty albatross P. fusca (Endangered) were decreasing, whereas numbers of light-mantled albatross P. palpebrata (Near Threatened) were increasing. Extending the counts to 2014 reversed these trends, with numbers of sooty albatrosses increasing from 2006 to 2014, and numbers of light-mantled albatrosses decreasing from 2007 to 2014. Confidence in island-wide counts is low due to the cryptic nature of the albatrosses on their largely inaccessible cliff-side nest sites, as well as counts for sooty albatrosses taking place late in the incubation period when 10?20% of nests have already failed. Given the greater conservation concern for the sooty albatross, we recommend that dedicated annual counts be conducted during the early incubation period, and be repeated shortly after the chicks hatch (late December), mid-way through the nestling period (late February) and prior to fledging (late April), to give a better idea of breeding success. Count zones also should be revised to facilitate more accurate counts, ensuring more reliable estimates of sooty albatross population trends at Marion Island. 相似文献
672.
N. Rollet G.A. Logan G. Ryan A.G. Judd J.M. Totterdell K. Glenn A.T. Jones F. Kroh H.I.M. Struckmeyer J.M. Kennard K.L. Earl 《Marine and Petroleum Geology》2009
A variety of shallow gas indicators and fluid migration pathways have been interpreted from new sub-bottom profiler, multibeam bathymetry, side-scan sonar, and echo-sounder data together with geochemical analyses of sampled sediments from the northern Arafura Sea, offshore Northern Australia. This study provides new geological data and a seismic stratigraphy of the youngest units in the Money Shoal Basin, in an area that has not been closely studied in over 30 years. The shallow gas indicators include pockmarks, low frequency enhanced reflectors and acoustic blanking. These indicators are supported by gas within shallow cores. Geochemistry indicates that this gas has a microbial origin but deeper fluid movement is also suggested by the presence of interpreted hydrocarbon slicks based on synthetic aperture radar data. A region of likely hydrocarbon seepage is indicated by the clear coincidence of shallow gas indicators with an area of increased faulting and a zone of poor quality seismic data (recognised on conventional seismic data), together with anomalies (interpreted on remote-sensing data) aligned with mapped deep structures. 相似文献
673.
Ryan Plummer Danuta de Grosbois Derek Armitage Rob C. de Loë 《Global Environmental Change》2013,23(4):749-763
Assessing vulnerability related to water is a global concern and especially important to populations experiencing multiple exposures and sensitivities. Approaches are required that span social and physical concerns, and that bridge multiple types and forms of knowledge. This research investigates the water vulnerability of three First Nation communities in Ontario, Canada. A collaborative process was used to build an integrative understanding of water vulnerability, develop an associated instrument, and undertake the community scale assessments. Results from the assessment provided communities with a comprehensive overview of water vulnerability, and pointed to gaps in knowledge and specific areas where attention was needed. Conducting assessments at a community scale following the methodology employed in this research responds to the need for integration and context sensitivity when engaging in water vulnerability assessments and introduces innovations to existing assessment tools. A holistic approach to water vulnerability assessment provided decision-makers with the context-specific details and empirical insights they require to prioritize issues and allocate resources. 相似文献
674.
Suzanne O'Connell Belen Alonso Kim A. Kastens Andrés Maldonado Alberto Malinverno C. Hans Nelson Alberto Palanques William B. F. Ryan 《Geo-Marine Letters》1985,5(3):149-156
The Valencia Valley is a Quaternary, 200 km long deep-sea valley in the Valencia Trough, Western Mediterranean Sea. A swathmapping survey approximately mid-way along the valley length, where the floor has an average gradient of 1:250 (0.2°), shows valley walls that rise 200 to 350 m above the valley floor, with slopes of 2 to 18°. Sediment forming the walls is undergoing retrogressive, upslope-directed slumping with increasing bedding disruption along steeper walls. The valley exhibits a winding course with steep outer and gentler inner walls around bends, and bedforms on the valley floor. Lateral migration around bends is less than 5 km and the valley is deeply entrenched into Quaternary-bedded sediments. 相似文献