Retreived bacteria from Noctiluca miliaris (green) bloom of the northeastern Arabian Sea     

BASU Subhajit  MATONDKAR SG Prabhu  FURTADO Irene 《中国海洋湖沼学报》2013,31(1):10-20

In recent years, seasonal blooms of the dinoflagellate Noctiluca miliaris have appeared in the open-waters of the northern Arabian Sea (NAS). This study provides the first characterization of bacteria from a seasonal bloom of green Noctiluca of NAS (20°N?17°N and 64°E–70°E), during the spring-inter-monsoon cruise of Sagar Sampada 253, in March 2007. Bacterial growth as assessed by most-probable number (MPN) and plate counts, revealed ‘variable-physiotypes’ over a wide range of salinities (0%–25% w/v NaCl), pH levels (5–8.5), and organic nutrient strengths, in comparison to non-bloom waters. MPN indices of bacteria in surface waters of bloom stations *DWK and *PRB, corresponded to (3.08–4.41)×10³ cells/mL at 3.5% NaCl (w/v), and (2.82–9.49)×10² cells/mL at 25% (w/v) NaCl in tryptone-yeast extract broth (TYE). Plate counts were (1.12–4)×10⁶ CFU/mL at 0% (w/v) NaCl, (1.28–3.9)×10⁶ CFU/mL at 3.5% (w/v) NaCl, and (0.4–7)×10⁴ CFU/mL at 25% NaCl (w/v) on TYE. One-tenth-strength Zobell’s gave (0.6–3.74)×10⁵ CFU/mL at pH 5 to (3.58–7.5)×10⁵ CFU/mL at pH 8.5. These bacteria were identified to the genera Bacillus, Cellulomonas, Staphylococcus, Planococcus, Dietzia, Virgibacillus, Micrococcus, Sporosarcinae, Leucobacter, and Halomonas. The identity of three strains (GUFBSS253N2, GUFBSS253N30, and GUFBSS253N84) was confirmed through 16S rDNA sequence homology as Bacillus cohnii, Bacillus flexus, and Bacillus cereus. The ～2–3-fold higher plate counts of culturable bacteria from the open-waters of the NAS indicate that these bacteria could critically determine the biogeochemical dynamics of the bloom and its milieu. The role of these bacteria in sustaining/terminating the bloom is under evaluation.  相似文献   

Editorial     

Phil Potts  Mireille Polv 《Geostandards and Geoanalytical Research》2000,24(1):5-5

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Do environmental factors influence the movement of estuarine fish? A case study using acoustic telemetry     

A.-R. Childs  P.D. Cowley  T.F. Næsje  A.J. Booth  W.M. Potts  E.B. Thorstad  F. Økland 《Estuarine, Coastal and Shelf Science》2008

Telemetry methods were used to investigate the influence of selected environmental variables on the position and movement of an estuarine-dependent haemulid, the spotted grunter Pomadasys commersonnii (Lacepède 1801), in the Great Fish Estuary, South Africa. Forty individuals (263–698 mm TL) were surgically implanted with acoustic coded transmitters and manually tracked during two periods (7 February to 24 March 2003; n = 20 and 29 September to 15 November 2003; n = 20). Real-time data revealed that spotted grunter are euryhaline (0–37) and are able to tolerate large variations in turbidity (4–356 FTU) and temperature (16–30 °C). However, the fish altered their position in response to large fluctuations in salinity, temperature and turbidity, which are characteristic of tidal estuarine environments. Furthermore, tidal phase had a strong influence on the position of spotted grunter in the estuary.  相似文献   

GeoPT3. International Proficiency Test for Analytical Geochemistry Laboratories - Report on Round 3     

Michael Thompson  Philip J. Potts  Jean S. Kane  Bruce W. Chappell 《Geostandards and Geoanalytical Research》1999,23(1):87-121

Results from seventy two laboratories participating in GeoPT3, round three of the international proficiency testing programme for analytical geochemistry laboratories, are presented. The report includes analytical results contributed by participating laboratories, together with the z-scores derived from these results using appropriate fitness for purpose criteria. These data are available for use as part of the laboratories' quality control procedures to assess the reliability of analysed results.  相似文献   

Editorial     

Phil Potts  Mireille Polv 《Geostandards and Geoanalytical Research》1999,23(2):135-135

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The effect of interface properties on retaining wall behaviour     

R. A. Day  D. M. Potts 《国际地质力学数值与分析法杂志》1998,22(12):1021-1033

A series of finite element analyses have been undertaken to investigate the effects of interface properties on the behaviour of a vertical retaining wall and the deformation of the ground around it. The boundary between a rigid embedded wall and the soil is modelled with zero thickness interface elements. Uniform translation of the wall has been studied. The analyses show the predicted limiting active and passive pressure on the wall are dependent on the maximum wall friction angle and are in reasonable agreement with accepted approximate analytical solutions. The limiting pressure is independent of the stiffness and dilation properties of the interface elements. The dilation properties of the interface have a significant effect on the ground surface deformation around the wall. © 1998 John Wiley & Sons, Ltd.  相似文献   

Metabolic activity throughout early development of dusky kob Argyrosomus japonicus (Sciaenidae)     

C Edworthy  NC James  B Erasmus  JOG Kemp  H Kaiser  WM Potts 《African Journal of Marine Science》2018,40(1):67-74

The physiology of fishes in the early stages of development remains poorly assessed despite the importance of identifying energy bottlenecks in organisms faced with changing environmental conditions. This study describes the metabolic activity of dusky kob Argyrosomus japonicus throughout its early development, from hatchling to settlement stage. Standard, routine and active metabolic rates (SMR, RMR and AMR, respectively) were assessed to determine the species’ metabolic scope and identify how metabolism changes with growth and development. Distinct metabolic changes occurred in association with developmental changes during the early life stages, with flexion-stage larvae showing significantly reduced metabolic scope (approx. 0.30 µmol O₂ ind.^–1 h^–1), representing an energy bottleneck. Based on these findings, it is likely that larvae of A. japonicus are most susceptible to environmental perturbations during flexion. The variability of metabolic rates during the diel cycle was also assessed and revealed that the early-stage larvae showed no preference for daylight, although settlement-stage juveniles were more active during daylight hours (RMR = 12.78 µmol O₂ ind.^–1 h^–1) than at night (RMR = 5.87 µmol O₂ ind.^–1 h^–1). These results suggest that metabolic measurements of the SMR of A. japonicus larvae can be taken at any time of the diel cycle until the settlement phase, when readings should take place at night.  相似文献   

Public awareness of marine environmental issues in the UK     

Stephen Fletcher  Jonathan S. Potts  Carolyn Heeps  Kate Pike 《Marine Policy》2009

This paper presents the results of a survey of public awareness of marine environmental issues within the context of the UK's National Maritime Museum. It was found that public interest in marine environmental issues is significant, but that gaps exist in terms of issue-specific awareness and that the availability of independent information on marine issues is limited. It is concluded that there are significant opportunities to develop the Museum's role in raising public awareness of marine environmental issues that build on its current activities and that of the Museum's partners.  相似文献   

A Study of Governance Arrangements for Land Use and Natural Resource Management Planning in Cape York Peninsula     

Ruth Potts  Karen Vella  Allan Dale  Neil Sipe 《The Australian geographer》2015,46(3):389-409

Complex intersecting social, economic and environmental dilemmas in Australia's Cape York Peninsula present a number of challenges for planners seeking to develop and implement land use and natural resource management (NRM) plans. There have been five different attempts at land use and NRM planning in Cape York Peninsula over the last 20 years. These processes have (to greater or lesser extents) failed to deliver community-owned and government-supported plans to guide development and/or the management of the region's natural resources. The region is remote, sparsely populated, and home to a significant Indigenous population. Much of the contestation within the region surrounds the access, use and ownership of the region's internationally valuable natural resources. This paper reviews, from the literature, the relevancy and applicability of criteria for best practice planning and governance. A range of identified best practice governance and planning principles are applied to assess the governance arrangements for planning in the Peninsula. The paper finds that decision-making arrangements for land use and NRM planning in the Peninsula are still in their infancy and are inadequate to support effective outcomes. The paper concludes that broader attention to best practice principles in governance for planning is needed to improve planning outcomes.  相似文献   

Bias in the Determination of Zr,Y and Rare Earth Element Concentrations in Selected Silicate Rocks by ICP‐MS when Using Some Routine Acid Dissolution Procedures: Evidence from the GeoPT Proficiency Testing Programme          下载免费PDF全文

Philip J. Potts  Peter C. Webb  Michael Thompson 《Geostandards and Geoanalytical Research》2015,39(3):315-327

The analytical results for the modified river sediment, SdAR‐1 circulated in Round 31 of the GeoPT proficiency testing programme, revealed unexpected discrepancies for Zr, Y and most higher atomic number rare earth elements, in determinations made by ICP‐MS using acid attack digestion methods. This investigation compares these ICP‐MS results with those obtained for SdAR‐1 by three other methods: (a) ICP‐MS using fusion/sintering for sample digestion, (b) XRF analysis and (c) INAA. The distribution of results for the elements Rb, Sr, Ce, Y, Yb and Zr is examined and compared with those of the test material for Round 25 of GeoPT, Paraná basalt, HTB‐1. A substantial proportion (though not all) of Y, Yb and Zr determinations in SdAR‐1 by ICP‐MS/acid attack was variably low (sometimes very low) compared with other methods. A detailed evaluation of the procedures used to determine these results indicated that successful determinations by ICP‐MS/acid attack could be made if digestions were made at 180 °C for 48 hr using at least 2 ml HF per 100 mg of sample. We suggest that the more benign conditions (used by many laboratories) resulted in incomplete digestion of resistant minerals, such as zircon.  相似文献