Benthic macrofauna and productivity regimes in the Barents Sea — Ecological implications in a changing Arctic     

Sabine K.J. Cochrane  Stanislav G. Denisenko  Paul E. Renaud  Christopher S. Emblow  William G. Ambrose Jr.  Ingrid H. Ellingsen  Jofrid Skarhamar 《Journal of Sea Research》2009,61(4):222-233

Benthic faunal assemblages were analysed from 47 stations in the central and southern parts of the Barents Sea, together with sedimentary and water column parameters, daily ice records and modelled integrated primary productivity. Sampling spanned areas influenced by Atlantic Water (AW) to those lying under Arctic Water (ArW), and included stations with mixed water masses. Ice cover suppressed water column productivity in the northern areas. Three main faunal groups were identified, based on similarity of numerical faunal composition. The northern and southern faunal groups were separated by the northernmost penetration of AW in the bottom water and the third group, the Hopen group, was influenced by modified bank water. Faunal abundances were significantly higher within the southern faunal group relative to the northern group, but the numbers of taxa present were similar. The particularly rich fauna of the Hopen group reflected sediment heterogeneity and tight pelagic–benthic coupling. These results suggest that a retreat and thinning of the ice cover in the Barents Sea likely will result in the northern parts of the Barents Sea becoming more Atlantic in character, with a higher productivity at the sea floor.  相似文献   

Macrofauna Communities in the Eastern Mediterranean Deep Sea   总被引：1，自引：0，他引：1  

Ingrid Kröncke  Michael Türkay  & Dieter Fiege 《Marine Ecology》2003,24(3):193-216

Abstract. During two expeditions with RV ‘Meteor’ in summer 1993 and winter 1997/98 the structural and functional diversity of the benthic system of the highly oligotrophic eastern Mediterranean deep sea was investigated. The macrofauna communities were dominated by polychaetes even at the deepest stations. The fauna at shallow stations was dominated by surface deposit feeders, whereas subsurface deposit feeders and predators generally increased with depth. A high percentage of suspension‐feeding Porifera was found in the Levantine Basin. Mean abundance and number of taxa of both expeditions were significantly correlated to depth and distance to the nearest coast as well as to the total organic carbon (TOC) content in sediments. Numbers of taxa and abundance decreased generally with depth, although lowest numbers were not found at the deepest stations but in the extremely oligotrophic Levantine and Ierapetra Basin. Biomass measured during the second cruise was extremely low in the Ierapetra Basin and comparable to other extreme oligotrophic seas. The significant correlations found for TOC contents and macrofauna with distance to coast during both expeditions apparently reflect the role of hydrographically governed transport of organic matter produced in coastal regions into greater and extreme depths of the Mediterranean Sea. Seasonal differences in macrofauna communities due to seasonal differences in food supply were not found. However, recent large‐scale hydrographic changes (Eastern Mediterranean Transient, EMT) might change the oligotrophy and, thus, the structure of the benthic communities in the Eastern Mediterranean deep sea.  相似文献   

Seasonal variability of epibenthic communities in different areas of the southern North Sea   总被引：2，自引：2，他引：2  

Reiss  Henning; Kroncke  Ingrid 《ICES Journal of Marine Science》2004,61(6):882-905

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Chandra smells a RRAT     

Bryan M. Gaensler  Maura McLaughlin  Stephen Reynolds  Kazik Borkowski  Nanda Rea  Andrea Possenti  Gianluca Israel  Marta Burgay  Fernando Camilo  Shami Chatterjee  Michael Kramer  Andrew Lyne  Ingrid Stairs 《Astrophysics and Space Science》2007,308(1-4):95-99

“Rotating RAdio Transients” (RRATs) are a newly discovered astronomical phenomenon, characterised by occasional brief radio bursts, with average intervals between bursts ranging from minutes to hours. The burst spacings allow identification of periodicities, which fall in the range 0.4 to 7 seconds. The RRATs thus seem to be rotating neutron stars, albeit with properties very different from the rest of the population. We here present the serendipitous detection with the Chandra X-ray Observatory of a bright point-like X-ray source coincident with one of the RRATs. We discuss the temporal and spectral properties of this X-ray emission, consider counterparts in other wavebands, and interpret these results in the context of possible explanations for the RRAT population. B.M.G. acknowledges the support of NASA through LTSA grant NAG5-13023 and of an Alfred P. Sloan Fellowship.  相似文献   

Prevention of oil spill from shipping by modelling of dynamic risk   总被引：1，自引：0，他引：1  

Eide MS  Endresen O  Breivik O  Brude OW  Ellingsen IH  Røang K  Hauge J  Brett PO 《Marine pollution bulletin》2007,54(10):1619-1633

This paper presents a new dynamic environmental risk model, with intended use within a new, dynamical approach for risk based ship traffic prioritisation. The philosophy behind this newly developed approach is that shipping risk can be reduced by directing efforts towards ships and areas that have been identified as high priority (high risk), prior to a potential accident. The risk model proposed in this paper separates itself from previous models by drawing on available information on dynamic factors and by focusing on the ship's surroundings. The model estimates the environmental risk of drift grounding accidents for oil tankers in real time and in forecast mode, combining the probability of grounding with oil spill impact on the coastline. Results show that the inherent dynamic risk introduced by an oil tanker sailing along the North Norwegian coast depends, not surprisingly, significantly upon wind and ocean currents, as well as tug position and cargo oil type. Results of this study indicate that the risk model is well suited for real time risk assessment, and effectively separates low risk and high risk situations. The model is well suited as a tool to prioritise oil tankers and coastal segments. This enables dynamic risk based positioning of tugs, using both real-time and projected risk, for effective support in case of a drifting ship situation.  相似文献   

Assessing the effects of Irgarol 1051 on marine phytoplankton populations in Key Largo Harbor, Florida     

Zamora-Ley IM  Gardinali PR  Jochem FJ 《Marine pollution bulletin》2006,52(8):935-941

The antifouling boosting agent Irgarol 1051 is a strong inhibitor of the photosystem II (PSII) with high efficiency/toxicity towards algae. However, because some phytoplankton species are more sensitive to Irgarol than others, its persistent release into the environment could result in adverse changes in the phytoplankton community structure at heavily impacted sites such as marinas. Continuous monitoring in the Florida Keys showed Irgarol concentrations of up to 635 ngL(-1) in the canal system leading to Key Largo Harbor Marina (KLH) with a sharp decrease in concentration at stations offshore from the mouth of the canal. Preliminary phytoplankton community assessments from surface water samples collected in KLH between February and August 2004 showed changes in several phytoplankton species in concordance with the increase of the herbicide concentrations. Typical responses include an increase in the abundance of eukaryotes and Cryptomonas sp. as Irgarol concentrations increase.  相似文献   

The influence of both process descriptions and runoff patterns on predictions from a spatially distributed soil erosion model     

Ingrid Takken  Gerard Govers  Victor Jetten  Jeroen Nachtergaele  An Steegen  Jean Poesen 《地球表面变化过程与地形》2005,30(2):213-229

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Deep-fluids: Neptune meets Pluto   总被引：2，自引：0，他引：2  

Ingrid Stober  Kurt Bucher 《Hydrogeology Journal》2005,13(1):112-115

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The influence of impurities on the dissolution of Ca- and Sr-bearing barite at room temperature     

张学洪  朱义年Ingrid Stober Kurt Bucher 《中国地球化学学报》2006,25(1):71-84

1INTRODUCTION BARITE(BASO4)ISANEXTREMELYINSOLUBLESALT;THISAROUSESPROBLEMSINPETROLEUMINDUSTRYBECAUSE BASO4ISAPARTICULARLYINTRACTABLESCALINGAGENT.BARITE PRECIPITATIONINTHEWELLBOREENVIRONMENTGENERALLYRE QUIRESMECHANICALREMOVAL,WITHCONSIDERABLEASSOCIAT EDEXPE…  相似文献   

Case studies on the origin of basalt: III. Petrogenesis of the Mauna Ulu eruption,Kilauea, 1969–1971     

Albrecht W. Hofmann  Mark D. Feigenson  Ingrid Raczek 《Contributions to Mineralogy and Petrology》1984,88(1-2):24-35

During the Mauna Ulu flank eruption on Kilauea, Hawaii, the concentrations in the lavas of the minor elements K, P, Na and Ti, and the incompatible trace elements (analyzed by isotope dilution) K, Rb, Cs, Ba, Sr, and the REE (except Yb) decreased monotonically and linearly with the time (or date) of the eruption. At the same time, the concentrations of the major elements and of Yb, and the ratios of K/Rb, K/Cs, Ba/Rb, ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd remained constant. Most of the scatter in the raw concentration data is removed by a simple correction for olivine (plus chromite) fractionation previously established by Wright et al. (1975). These results are explained by simple equilibrium partial melting of a uniform source. The degree of melting increased by about 20% of the initial value during the course of the eruption. The trace element data are inverted by the method originated by Minster and Allègre (1978) and simplified by Hofmann and Feigenson (1983). The source has the following element (or isotope) ratios: K/Rb=501±7, Ba/Rb=14.0±0.5, Rb/Cs=95±7, Rb/Sr=0.0193 (+0.0045, –0.0090), (Ce/Ba)_CN= 1.1±0.1, (Sr/Ba)_CN=1.19 (+0.30, –0.19), ⁸⁷Sr/⁸⁶Sr=0.703521±0.000016, and ¹⁴³Nd/¹⁴⁴Nd=0.512966±0.000008. The REE pattern of the source has a nearly flat or slightly negative slope (=relative LREE enrichment) between Ce and Dy and a strongly positive slope between Dy and Yb. However, this relative HREE enrichment is poorly constrained by the analytical data, is highly model dependent and may not be a true source feature. The Yb concentration in the source is particularly poorly constrained because it is essentially constant in the melts. On the other hand, this special feature demonstrates that Yb must be buffered by a mineral phase with a high partition coefficient for Yb, namely garnet. The calculated clinopyroxene/garnet ratio in the source is roughly equal to one. In contrast, the source of Kohala volcano had previously been found to contain little or no garnet.  相似文献