The circulation of the deep Atlantic Ocean during the height of the last ice age appears to have been quite different from today. We review observations implying that Atlantic meridional overturning circulation during the Last Glacial Maximum was neither extremely sluggish nor an enhanced version of present-day circulation. The distribution of the decay products of uranium in sediments is consistent with a residence time for deep waters in the Atlantic only slightly greater than today. However, evidence from multiple water-mass tracers supports a different distribution of deep-water properties, including density, which is dynamically linked to circulation.

The separate roles of oceanic heat advection and orbital forcing on influencing early Holocene temperature variability in the eastern Nordic Seas is investigated. The effect of changing orbital forcing on the ocean temperatures is tested using the 1DICE model, and the 1DICE results are compared with new and previously published temperature reconstructions from a transect of five cores located underneath the pathway of Atlantic water, from the Faroe‐Shetland Channel in the south to the Barents Sea in the north. The stronger early Holocene summer insolation at high northern latitudes increased the summer mixed layer temperatures, however, ocean temperatures underneath the summer mixed layer did not increase significantly. The absolute maximum in summer mixed layer temperatures occurred between 9 and 6 ka BP, representing the Holocene Thermal Maximum in the eastern Nordic Seas. In contrast, maximum in northward oceanic heat transport through the Norwegian Atlantic Current occurred approximately 10 ka BP. The maximum in oceanic heat transport at 10 ka BP occurred due to a major reorganization of the Atlantic Ocean circulation, entailing strong and deep rejuvenation of the Atlantic Meridional Overturning Circulation, combined with changes in the North Atlantic gyre dynamic causing enhanced transport of heat and salt into the Nordic Seas.

The Holocene section of the marine sediment core PSh-5159N, located in the SW Barents Sea, has been studied at high resolution with a multiproxy approach. A well-stratified water column occurred at the site 11—9.8 ka BP. The stratification was probably a result of a winter sea ice cover and/or fresh, warm surface waters during summer. Stratification and resultant reduction in air—sea interaction allowed for warmer bottom water temperatures. The general situation 11—9.8 ka BP could have been associated with an anomalous high-pressure system over the Nordic Seas and the Arctic Ocean. During the 11—10.5 ka BP interval the polar front was located close to the Barents Sea margin. The polar front moved towards the site from 10.5 ka BP, and from 9.8 to 7.5 ka BP it was probably located close to the site. At 7.5 ka BP the polar front retreated eastwards as the present-day oceanographic pattern established. The mid Holocene was in general characterized by rather stable conditions. In contrast, highly variable conditions are recorded throughout the late Holocene. Episodic expansions of the coastal water influenced zone are typical for the last 2.5 ka BP. Predominantly cold conditions and reduced southwesterly wind strength are suggested during these episodes. The Holocene temperature variability seems in general to be of larger amplitude than instrumentally recorded temperature changes in the SW Barents Sea.

This review analyzes the issues associated with biodegradation of glyphosate (N-(phosphonomethyl)glycine), one of the most widespread herbicides. Glyphosate can accumulate in natural environments and can be toxic not only for plants but also for animals and bacteria. Microbial transformation and mineralization ofglyphosate, as the only means of its rapid degradation, are discussed in detail. The different pathways of glyphosate catabolism employed by the known destructing bacteria representing different taxonomic groups are described. The potential existence of alternative glyphosate degradation pathways, apart from those mediated by C-P lyase and glyphosate oxidoreductase, is considered. Since the problem of purifying glyphosate-contaminated soils and water bodies is a topical issue, the possibilities of applying glyphosate-degrading bacteria for their bioremediation are discussed.

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Holocene paleoceanography of the northern Barents Sea and variations of the northward heat transport by the Atlantic Ocean. Boreas, Vol. 30, pp. 2-16. Oslo. ISSN 0300-9483.Foraminiferal assemblage s were studied in northern Barents Sea core ASV 880 along with oxygen and carbon isotope measurement s in planktoni c (N. pachyderm a sin.) and benthic (E. clavatum ) species. AMS C-14 measurements performed on molluscs Yoldiella spp. show that this core provides a detailed and undisturbe d record of Holocene climatic changes over the last 10 000 calendar years. Surface and deep waters were very cold (< 0°C) at the beginning of the Holocene. C. reniforme dominated the highly diverse benthic foraminiferal assemblage . From 10 to 7.8 cal. ka BP, a warming trend culminated in a temperature optimum, which developed between 7.8 and 6.8 cal. ka BP. During this optimum, the input of Atlantic water to the Barents Sea reached its maximum. The Atlantic water mass invaded the whole Franz Victoria Trough and was present from subsurface to the bottom. No bottom water, which would form through rejection of brine during winter, was present at the core depth (388 m). The water strati cation was therefore greatly reduced as compared to the present. An increase in percentag e of I. helenae/norcrossi points to long seasonal ice-free conditions. The temperature optimum ended rather abruptly, with the return of cold polar waters into the trough within a few centuries . This was accompanie d by a dramatic reductio n of the abundanc e of C. reniforme. During the upper Holocene, the more opportunisti c species E. clavatum became progressivel y dominant and the water column was more strati ed. Deep water in Franz Victoria Trough containe d a signi cant amount of cold Barents Sea bottom water as it does today, while subsurface water warmed progressivel y until about 3.7 cal. ka BP and reached temperatures similar to those of today. These long-term climatic changes were cut by several cold events of short duration, in particula r one in the middle of the temperatur e optimum and another, which coincides most probably with the 8.2 ka BP cold event. Both long-and short-ter m climatic changes in the Barents Sea are associate d with changes in the ow of Atlantic waters and the oceanic conveyor belt. Jean-Claud e Duplessy

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