The cold-water coral Lophelia pertusa (Scleractinia) and enigmatic seabed mounds along the north-east Atlantic margin: are they related?

In this study, an updated distribution of Lophelia pertusa between the Porcupine Seabight and Norwegian shelf is presented. It seems unlikely that enigmatic mound structures observed at water depths of more than 570 m during acoustic seabed surveys, particularly to the west of the Shetland Islands, are related to the occurrence of L. pertusa. At these depths in the Faroe-Shetland Channel, the predominant influence of cold Arctic water precludes its growth. Iceberg dumpsites are also considered unlikely explanations for the origin of these mounds, and they are interpreted as most likely to be related to the release of fluids at the seabed. When mound structures were investigated, no scleractinian corals were recovered at water depths >500 m. This study shows the importance of seabed temperature as an environmental control on cold-water coral distribution. The significance of cold-water coral habitats in sustaining high levels of local-scale biodiversity is now becoming apparent in parallel with increased hydrocarbon extraction and fishing activity beyond the shelf edge. There is growing evidence that these areas have been marked by the passage of deep-water trawls. It seems likely that trawling activity has already reduced the extent of cold-water coral distribution in this region of the north-east Atlantic.     

Distribution of enteric bacteria in Antarctic seawater surrounding the Port-aux-Français permanent station (Kerguelen Island)

Untreated sewage has been released from Port-aux Fran?ais station, Kerguelen Island, into the Southern Ocean for more than 50 years. We investigated the spatial distribution of faecal bacteria indicators during a one-year survey conducted in seawater off Morbihan Bay near the French permanent station of the Kerguelen Island (49 degrees 21(')S, 70 degrees 30(')E). Seawater samples were taken bimonthly from nine stations evenly distributed around the sewage outfalls of the station. Escherichia coli and enterococci were estimated using specific microplates (Miniaturized method for the enumeration of E. coli or enterococci in surface and waste waters, "MU/EC or MU/SF methods", BIO-RAD( Copyright)). In order to evaluate the role of seasonal changes of environmental parameters on the survival of enteric bacteria, total and saprophytic bacterial abundances were also estimated in all seawater samples. High densities of faecal bacteria (maximum 10(4) cells 100 ml(-1)) were found in seawater surrounding the sewage outfall. However, enteric bacterial counts decreased rapidly with increasing distance from the outfall. In all samples collected further than 2 km from the outfall, the bacterial indicators were absent or present in small numbers (<10 cells 100 ml(-1)). Faecal coliforms were not detected in samples collected at pristine sites located 10 km from Port-aux-Fran?ais. Despite these low contamination levels, faecal bacteria were always detected in the vicinity of the sewage outfall during the seasonal survey. The concentration of faecal bacteria may be related to the number of people inhabiting the station.     

Activity concentration of caesium-137 in seawater and plankton of the Pomeranian Bay (the Southern Baltic Sea) before and after flood in 1997

Activity coefficients of 137Cs determined during culminating flood waters in August 1997 in the estuary of the Oder River, discharging to the Pomeranian Bay as well as in the coastal and open-seawaters of the Bay, did not show enhanced levels of the nuclide as compared to those measured before the flood. It is thus concluded that the flood did not contribute to releasing the nuclide from eroded soil particles. The bioconcentration factors of 137Cs in the riverine plankton has been found to be one to two orders of magnitude higher than those determined in the Pomeranian Bay plankton.     

俄罗斯贝加尔湖区伸展构造及与中国东部伸展构造对比

在晚白垩世-始新世夷平面基础上,由于断裂作用形成了贝加尔裂谷系。断裂作用最大幅度超过10 km。在裂谷系中心部位发育的断层长度最大、最深、最早,并以准对称形式向四周扩展。贝加尔裂谷系是在地幔隆起和印度-欧亚大陆碰撞双重作用下形成。贝加尔裂谷系与中国东部新生代断陷盆地和汾渭裂谷系同时形成,并有密切的成因联系。它们的形成不仅受太平洋板块的俯冲和印度-欧亚大陆碰撞的制约和影响,而且位于中国西南部的地幔流发散中心,呈扇状向太平洋区流动,可能是它们在更深层次上的共同场源基础。     

Bearing the burden of boat harbours: heavy contaminant and fouling loads in a native habitat-forming alga

Boat harbours are an increasingly common form of artificial habitat. This paper presents a comparative study of contaminants and foulers of a habitat-forming native kelp (Saccharina latissima) in four marinas and four reference locations along the south-west coast of the UK. Fouling of algal laminae was light (<2% cover) in reference locations, while epibiota cover ranged from 25% to 80% of laminae in marinas. Metals associated with antifouling paints were up to six times more concentrated in algal tissues from marinas than from the reference locations. Marinas also carried the greatest cover and diversity of non-indigenous epibiota on the kelp laminae. This indicates not only a potential stress to kelps in these environments, but also the possibility that detached laminae will act as vectors for the dispersal of non-indigenous species. The development of boat harbours creates habitats that are high risk source localities for pollution-tolerant fouling organisms.     

Polybrominated diphenyl ethers (PBDEs) in marine foodstuffs in Australia: residue levels and contamination status of PBDEs

Edible marine products (n=24) collected from the fish markets in Adelaide, Australia, were analysed for the presence of polybrominated diphenyl ethers (PBDEs). The total concentration of 11 PBDE congeners found in the marine products ranged from 1.01 to 45 ng/g fresh weight. Among the samples analysed, imported silver fish and prawns from Vietnam and Thailand respectively, recorded the highest ∑PBDEs concentrations (45.10 and 43.29 ng/g fresh weight) as against 13.08 and 12.57 ng/g fresh weight in Australian king prawns and Gar fish. BDE-209 was the most dominant congener in the marine products followed by BDE-47, 99 and 100. The calculated average daily intakes of ∑PBDEs per day for an adult male and female (19 or more years old) were 1026.8 and 1188.4 ng/kg per day, respectively. This study clearly shows that the dietary exposure to marine foods can contribute to PBDEs accumulation in human body.     

2009年拉奎拉地震后柔层机制的初步分析

对2009年4月6日阿布鲁佐地震造成的破坏观察表明,填充墙和钢筋混凝土结构之间局部的相互作用会产生柔层机制和脆性破坏。目前的实例研究成果是基于对佩蒂诺地区地震破坏观察的基础上进行的。建立了以模拟设计程序为基础的分析模型,并采用时程分析验证了由观察破坏所凸现出的结构倒塌的原因。通过考虑地面运动的所有分量,对这种破坏机制进行了研究。注意了砖砌块填充墙的非线性性能,考虑了填充墙力学性能的两个参数的假定,给出了表现这些非结构构件典型特征的不确定性。用三支撑杆宏观模型对填充墙进行非线性模拟,以考虑钢筋混凝土框架和填充墙之间局部和整体的相互作用。地震波输入是所研究结构附近在主震期间记录的真实信号。在评估中,选用了不同的抗剪承载力模型。分析结果似乎非常近似地证实了破坏观察所发现的主要类似倒塌情景;柱子缺乏合适的细部设计使得填充墙和钢筋混凝土柱之间的局部相互作用和地面运动的强烈垂直分量是造成脆性破坏的主要原因。     

Assessment of Hurricane Ivan impact on chlorophyll-a in Pensacola Bay by MODIS 250 m remote sensing

The impact of Hurricane Ivan on water quality in Pensacola Bay was investigated by MODIS 250 m remote sensing of chlorophyll-a concentrations at different time slots before and after the hurricane event. Before the hurricane, the mean chlorophyll-a in the Bay was 5.3 μg/L. Heavy rainfall occurred during the hurricane landfall. The 48 h rainfall reached 40 cm and the peak storm surge reached 3 m on 9/16. After the rainstorm and during the storm surge on 9/17/2004, the mean chlorophyll-a concentration substantially increased to 14.7 μg/L. 26.3% water area was in the poor-water-quality condition (chl-a > 20 μg/L). This indicates that heavy nutrient loads from urban stormwater runoff and storm-surge inundation simulated chlorophyll bloom. After the end of the storm surge on 9/18/2004, the mean chlorophyll dropped to 2.0 μg/L, suggesting the effective flushing of polluted water from the bay to the Gulf of Mexico by the storm-surge. The good water quality condition lasted for almost several weeks after the storm surge. The peak river flow, arriving on the 4th day after the peak storm surge, did not alter the good water quality situation in the bay. This indicates that urban stormwater runoff rather than the river inflow is the major pollutant source for water quality in Pensacola Bay during the hurricane.     

Inter- and intra-annual patterns of Ulva prolifera green tides in the Yellow Sea during 2007-2009, their origin and relationship to the expansion of coastal seaweed aquaculture in China

The large green-tide events that occurred in the Yellow Sea in 2008 (3489 km²) and 2009 (4994 km²) are shown to be novel events preceded only once by a much smaller event in 2007 (82 km²). The blooms originated in the coastal area of Jiangsu province and spread north-east towards the Shandong Peninsula. The blooms grew at different rates and mesoscale variability in surface winds explained the differences in the spatial and temporal patterns of blooms in 2008 and 2009. The 2009 bloom was tracked to its origin immediately offshore of extensive intertidal flats between Yancheng and Nantong where recent rapid expansion of Porphyra aquaculture has occurred. We review published hypotheses which have been advanced to explain the occurrence of blooms and in light of our findings, we conclude that the accumulation and disposal of waste Ulva prolifera from Porphyra aquaculture rafts is the most likely cause of the blooms.     

Plastic ingestion in Franciscana dolphins, Pontoporia blainvillei (Gervais and d'Orbigny, 1844), from Argentina

Plastic debris (PD) ingestion was examined in 106 Franciscana dolphins (Pontoporia blainvillei) incidentally captured in artisanal fisheries of the northern coast of Argentina. Twenty-eight percent of the dolphins presented PD in their stomach, but no ulcerations or obstructions were recorded in the digestive tracts. PD ingestion was more frequent in estuarine (34.6%) than in marine (19.2%) environments, but the type of debris was similar. Packaging debris (cellophane, bags, and bands) was found in 64.3% of the dolphins, with a lesser proportion (35.7%) ingesting fishery gear fragments (monofilament lines, ropes, and nets) or of unknown sources (25.0%). PD ingestion correlated with ontogenetic changes in feeding regimes, reaching maximum values in recently weaned dolphins. Because a simultaneous increase in gillnet entanglement and the bioaccumulation of heavy metals take place at this stage, the first months after trophic independence should be considered as a key phase for the conservation of Franciscana dolphin stocks in northern Argentina.