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31.
Torkild Tveraa Bernt-Erik Sæther Ronny Aanes Kjell Einar Erikstad 《Behavioral ecology and sociobiology》1998,43(2):73-79
In Procellariiformes, the parents guard the chick after it has attained homeothermy. This strategy may reduce the probability
that a small chick is taken by predators, but is costly as only one parent can forage at a time. The decision to leave the
chick may therefore be a compromise between the chick's vulnerability to predators, the body condition of the parent on the
nest and whether the foraging parent returns in time. We studied how the number of days that parents guarded the chick was
related to the body mass of the parent at the nest and the time the foraging parent spent at sea in the Antarctic petrel Thalassoica antarctica. We also examined how the body mass of the parent on the nest and the duration of the foraging trips influenced the chicks'
body condition at the end of the guarding period. When the foraging parent did not return to the nest in time to relieve its
mate, the number of days the parent on the nest kept guarding the chick was positively related to its body mass on arrival
in the colony. The number of days the foraging parent spent at sea was positively related to the body mass of its mate, but
those that returned in time had a shorter stay at sea relative to their mate's body mass than those that did not return before
their mate had left. Apparently, both the body mass of the parent at the nest and the ability of the foraging parent to adjust
its stay at sea to the mate's body mass is important for the number of days the parents guard the chick and also the chick's
body condition at this point. The inability to return to the nest before the mate has left may be the result of needing a
minimum amount of time at sea to find food, or because some parents having low foraging success and therefore prolong their
stay at sea.
Received: 10 October 1997 / Accepted after revision: 14 March 1998 相似文献
32.
Gast n Azziz Mat as Gim nez H ctor Romero Patricia M. Valdespino-Castillo Luisa I. Falc n Lucas A. M. Ruberto Walter P. Mac Cormack Silvia Batista 《Frontiers of Environmental Science & Engineering》2019,13(3):44
33.
南半球海洋大气气溶胶单颗粒的理化特性分析 总被引:1,自引:1,他引:1
运用透射电子显微镜-X射线能谱技术分析了中国第29次南极科考期间采集的大气气溶胶单颗粒样品,获得颗粒物的形貌特征、混合状态、成分组成及数量分布等信息.结果表明,航渡区域海洋上空的颗粒物主要表现为4类:海盐颗粒、矿物颗粒、富硫颗粒和含碳颗粒,其中海盐颗粒占主导,本研究将海盐颗粒又分为新鲜、部分老化及完全老化的海盐颗粒.部分和完全老化的海盐颗粒占海盐颗粒总数的86%,且部分老化的海盐颗粒表面及完全老化的海盐颗粒以长条状Na2SO4成分为主.同时,发现两处采样点(印度洋中东部和南极内陆)的样品中富硫颗粒较多,根据后向气团轨迹判断这些富硫颗粒主要来源于海洋地区,推测是由海洋表面浮游生物释放的二甲基硫(dimethyl sulfide,DMS)经过大气氧化形成.本研究表明,南半球海洋大气中海盐颗粒老化是由海洋表面释放的DMS控制,这不同于北半球海洋大气中人为源影响的海盐颗粒老化现象. 相似文献
34.
Bacterial diversity in Fez tanneries and Morocco’s Binlamdoune River,
using 16S RNA gene based fingerprinting 总被引:1,自引:0,他引:1
The response of bacteria to various carbohydrates in the deep-sea sediments and the Antarctic soils was investigated using cellulose, chitin, and olive oil. It was found that the carbohydrates significantly increased the corresponding specific ectoenzyme activity (β- glucosidase, β-N-acetylglucosaminidase, lipase) in the samples from deep-sea sediments. In the case of Antarctic soil samples, the cellulose or olive oil amendments had minor or no effect on β-glucosidase or lipase activity, except the chitin which stimulated β- N-acetylglucosaminidase production. The responses of the bacteria in the deep-sea sediment sample WP02-3 and the Antarctic soil sample CC-TY2 towards the chitin amendment were further analyzed. Chitin amendments were shown to stimulate the ectoenzyme activity in all the tested sediments and the soils. The bacterial response before and after the carbohydrates amendments were compared by denaturing gradient gel electrophoresis and quantitative competitive polymerase chain reaction. Significant changes were found in the structure and density of the bacterial community in the deep sea sediments as compared to the Antarctic soil sample, where the effects were relatively lower. There was no change in the bacterial population in both studied samples in response to carbohydrates amendments. These data indicate that the bacterial communities in the oligotrophic deep-sea sediments are more dynamic than that in the Antarctic soils as they respond to the nutrient sources efficiently by regulation of ectoenzyme activity and/or changing community structure. 相似文献
35.
The nutraceutical market for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) is promoting fishing for Euphasia superba (Antarctic krill) in the Southern Ocean and Calanus finmarchicus in Norwegian waters. This industry argues that these species are underexploited, but they are essential in their ecosystems, and climate change is altering their geographical distribution. In this perspective, we advocate the cessation of fishing for these species to produce nutraceuticals with EPA and DHA. We argue that this is possible because, contrary to what this industry promotes, the benefits of these fatty acids only seem significant to specific population groups, and not for the general population. Next, we explain that this is desirable because there is evidence that these fisheries may interact with the impact of climate change. Greener sources of EPA and DHA are already available on the market, and their reasonable use would ease pressure on the Arctic and Antarctic ecosystems. 相似文献
36.
南极普里兹湾与太平洋、印度洋海水中90Sr和137Cs的研究 总被引:3,自引:0,他引:3
通过对太平洋、印度洋、南极普里北湾表层海水中^90Sr、^137Cs的分析,可以看出北半球放射必疹高于南半球。南极海域活度最你荒废 域人工放射性核素仍与大气沉降有关。全球人工放性活度吾下降趋势,但各海区下降的程度不同。南极普里兹湾夏季深层水的通升是影响该海区放射性水平的一个重要因素。局部区域的人工放射必不知 度与采样时间和地理位置有关。 相似文献
37.
Elemental composition of surface waters in the Antarctic Peninsula and interactions with the environment 总被引:3,自引:0,他引:3
The fast changes in chemical and biological properties of many coastal and inland waters in the last decades reflect the pressure of man on the environment. The surface waters of the Antarctic Peninsula, located far from industrial or populated areas, could eventually be used as background lines. Surface water samples were taken from five lagoons of King George Island, Antarctic Peninsula, and from the Kitiesh Lake. Sample pH and electrical conductivity were analysed in situ and in the laboratory, respectively. The dissolved fractions were analysed in 1997 and 1998. Total concentrations only for 1998 were determined in another fraction adjusted to pH 2. Aluminium, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Sn, Sb, Ba, Bi, and Pb were quantified in all samples by means of inductively coupled plasma-mass spectrometry (ICP-MS). Total and dissolved elemental concentrations were discussed considering the composition of particulate material suspended in the waters removed by streams or by water runoff, or from atmospheric aerosols. Concentrations of dissolved elements change from one lagoon to another. Total and dissolved elemental concentrations could be related to water movement by windstorms, to chemical mechanisms in water and/or to natural and anthropogenic atmospheric factors. 相似文献
38.
39.
Susan Bengtson Nash Stephen R. Rintoul Iain Staniland Megan Tierney 《Environmental pollution (Barking, Essex : 1987)》2010,158(9):2985-2991
In order to investigate the extent to which Perfluorinated Contaminants (PFCs) have permeated the Southern Ocean food web to date, a range of Antarctic, sub-Antarctic and Antarctic-migratory biota were analysed for key ionic PFCs.Based upon the geographical distribution pattern and ecology of biota with detectable vs. non-detectable PFC burdens, an evaluation of the potential contributory roles of alternative system input pathways is made. Our analytical findings, together with previous reports, reveal only the occasional occurrence of PFCs in migratory biota and vertebrate predators with foraging ranges extending into or north of the Antarctic Circumpolar Current (ACC).Geographical contamination patterns observed correspond most strongly with those expected from delivery via hydrospheric transport as governed by the unique oceanographic features of the Southern Ocean. We suggest that hydrospheric transport will form a slow, but primary, input pathway of PFCs to the Antarctic region. 相似文献
40.
Fei Liu 《中国人口.资源与环境(英文版)》2017,15(4):357-364
This study conducted a bibliometric analysis of 1251 articles related to Antarctic krill from 1960 to2015, based on the Core Collection in Thomson Reuters' Web of Science. We analyzed the results from four aspects: annual distribution, Web of Science categories and the major journals, international collaboration and author keywords. The Antarctic krill research has developed rapidly since 1978, with an increasing article output. The studies mostly focused on the fields of marine and freshwater biology, oceanography, and ecology. Polar Biology, Marine Ecology-Progress Series and Deep-Sea Research Part Ⅱ-Topical Studies in Oceanography, were the top three journals to publish the Antarctic krill-related papers. Although Russia is the earliest state to report Antarctic krill, U.S.A. and England were leaders with the largest output quantity and the highest cooperation frequencies. The researches in PR China have taken a blooming since 2009 and will play a more and more important role in the world. The frequencies of author keywords were counted. The high-frequency keywords were further divided into four groups with cohesive subgroup analysis, which suggested the major themes. This paper depicts the existing publications on Antarctic krill. Our goal is to serve a point of reference and provide the direction for the future work. 相似文献