Deccan volcanism linked to the Cretaceous-Tertiary boundary mass extinction: New evidence from ONGC wells in the Krishna-Godavari Basin     

G. Keller  P. K. Bhowmick  H. Upadhyay  A. Dave  A. N. Reddy  B. C. Jaiprakash  T. Adatte 《Journal of the Geological Society of India》2011,78(5):399-428

A scientific challenge is to assess the role of Deccan volcanism in the Cretaceous-Tertiary boundary (KTB) mass extinction. Here we report on the stratigraphy and biologic effects of Deccan volcanism in eleven deep wells from the Krishna-Godavari (K-G) Basin, Andhra Pradesh, India. In these wells, two phases of Deccan volcanism record the world’s largest and longest lava mega-flows interbedded in marine sediments in the K-G Basin about 1500 km from the main Deccan volcanic province. The main phase-2 eruptions (∼80% of total Deccan Traps) began in C29r and ended at or near the KTB, an interval that spans planktic foraminiferal zones CF1–CF2 and most of the nannofossil Micula prinsii zone, and is correlative with the rapid global warming and subsequent cooling near the end of the Maastrichtian. The mass extinction began in phase-2 preceding the first of four mega-flows. Planktic foraminifera suffered a 50% drop in species richness. Survivors suffered another 50% drop after the first mega-flow, leaving just 7 to 8 survivor species. No recovery occurred between the next three mega-flows and the mass extinction was complete with the last phase-2 mega-flow at the KTB. The mass extinction was likely the consequence of rapid and massive volcanic CO₂ and SO₂ gas emissions, leading to high continental weathering rates, global warming, cooling, acid rains, ocean acidification and a carbon crisis in the marine environment.  相似文献   

Production of biosurfactant by Nocardia otitidiscaviarum and its role in biodegradation of crude oil     

T. K. Vyas Ph.D.  B. P. Dave Ph.D. 《International Journal of Environmental Science and Technology》2011,8(2):425-432

Nocardia otitidiscaviarum microbial type cultural collection 6471 isolated from oil contaminated Alang India seawater was examined for production of surface active compound. Isolate shows halos and α-heamolysis on cetyl trimethyl ammonium bromide and blood agar respectively indicating the production of biosurfactant. Biosurfactant was extracted by precipitation and was partially purified. Partially purified product was characterized by thin layer chromatography and Infra-red spectroscopy and was identified as glycolipid. Sugar present in glycolipid was rhamnose and hence, biosurfactant was quantified as rhamnose equivalent. Role of cell-surface hydrophobicity and emulsification activity in correlation with biosurfactant production was examined. Correlation between biosurfactant production, growth and crude oil degradation was also examined and showed positive correlation at significant level 0.001 and 0.01 respectively. Thus, this is a first report on a marine strain of Nocardia otitidiscaviarum microbial type culture collection 6471, which can be a potential candidate for restoration of oil contaminated marine environment.  相似文献   

Analysis of photosynthetic picoeukaryote community structure along an extended Ellett Line transect in the northern North Atlantic reveals a dominance of novel prymnesiophyte and prasinophyte phylotypes     

Amy R. Kirkham  Ludwig E. Jardillier  Ross HollandMikhail V. Zubkov  Dave J. Scanlan 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(7):733-744

Photosynthetic picoeukaryotes (PPEs) of a size <3 ??m can contribute significantly to primary production. Here, PPE community structure was analysed along an extended Ellett Line transect, an area in the North Atlantic well studied by physical oceanographers but largely neglected in the field of microalgal ecology. Distribution patterns of specific PPE classes were determined using dot-blot hybridization analysis, while the taxonomic composition of specific PPE classes was revealed by phylogenetic analysis of plastid 16S rRNA gene sequences. In addition, we performed fluorescent in situ hybridization (FISH) analysis of seawater samples collected along the transect to provide a PCR-independent survey of class level PPE distribution patterns. We found the PPE community was dominated by members of the Prymnesiophyceae, Prasinophyceae and Mamiellophyceae. Interestingly, phylogenetic analysis revealed several novel Prymnesiophyceae and Prasinophyceae phylotypes (with only 85-96% identity to neighbouring sequences) within lineages for which cultured counterparts are unknown.  相似文献   

Actually achieving marine sustainability demands a radical re-think in approach, not 'more of the same'     

Morris D  O'Brien C  Larcombe P 《Marine pollution bulletin》2011,62(5):1053-1057

The UK is committed to meeting a series of ‘high-level marine objectives’ which are required to satisfy national obligations and to meet international commitments for the marine environment. There are more than 16 such international high-level policy driven obligations and commitments, together with more than 18 European and more than 12 of national origin. In the UK, there is an assumption that the current and planned monitoring will provide evidence to demonstrate achievement against these high-level objectives.  相似文献   

Mineralogical, petrological, and petrogenetic analysis of felsic intrusive rocks at the Sisson Brook W-Mo-Cu deposit, west-central New Brunswick     

ZHANG Wei  Christopher R.M. MCFARLANE  Dave LENTZ 《《地质学报》英文版》2013,87(Z1):831-834

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TAOS – The Taiwanese‐American Occultation Survey     

M. J. Lehner  C. Alcock  T. Axelrod  F. Bianco  Y.‐I. Byun  W.‐P. Chen  K. H. Cook  R. Dave  I. de Pater  J. Giammarco  S.‐K. King  T. Lee  J. Lissauer  S. L. Marshall  S. Mondal  T. Nihei  J. Rice  M. Schwamb  A. Wang  S.‐Y. Wang  C.‐Y. Wen  Z.‐W. Zhang 《Astronomische Nachrichten》2006,327(8):814-817

The Taiwanese‐American Occultation Survey (TAOS) seeks to determine the number and size spectrum for small (∼3 km) bodies in the Kuiper Belt. This will be accomplished by searching for the brief occultations of bright stars (R ∼ 14) by these objects. We have designed and built a special purpose photometric monitoring system for this purpose. TAOS comprises four 50 cm telescopes, each equipped with a 2048 × 2048 pixel CCD camera, in a compact array located in the central highlands of Taiwan. TAOS will monitor up to 2 000 stars at 5 Hz. The system went into scientific operation in the autumn of 2005. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

It’s Time To Learn About Learning: Where Should the Environmental and Natural Resource Governance Field Go Next?     

Andrea K. Gerlak  Tanya Heikkila  Sharon L. Smolinski  Derek Armitage  Dave Huitema  Brendan Moore 《社会与自然资源》2019,32(9):1056-1064

This Commentary reflects on the state of the scholarship on learning for environmental and natural resource policy and governance. How have we been learning about learning? We highlight theoretical and empirical advancements related to learning, as well as areas of divergence between learning theories and frameworks, and underdeveloped knowledge around processes and outcomes. To address these limitations and improve progress in both theory and practice, we offer recommendations for learning scholarship by focusing on how to collectively engage in ‘learning about learning’.  相似文献   

Physical determinants of intertidal communities on dissipative beaches: Implications of sea-level rise     

Tsuyuko Yamanaka  Dave RaffaelliPiran C.L. White 《Estuarine, Coastal and Shelf Science》2010

Sea-level rise is likely to cause significant changes in the morphodynamic state of beaches in the higher latitudes, resulting in steeper beaches with larger particle sizes. These physical changes have implications for beach invertebrate communities, which are determined largely by sediment particle size, and hence for ecosystem function. Previous studies have explored the relationships between invertebrate communities and environmental variables such as particle size, beach slope and exposure to wave action, and often these physical variables can be integrated in various indices of morphodynamic state. Most of these studies incorporated a full range of beach types that included wave-dominated surf beaches, where the wave action is harsh enough to enable reliable estimates of breaker height, a parameter included in several of the indices, and concluded that more dissipative beaches with gentler slopes and finer particle sizes often support a higher number of species and greater abundance than more reflective beaches. Whether these predictions remain valid for less wave-dominated beaches, where breaker height is more difficult to determine, is uncertain. In the present study, the abundance of meio- and macrofauna was quantified across a range of beaches in the UK, which are generally towards the lower energy end of the morphodynamic gradient, and their relationships with beach physical properties explored. No significant relationships were found between abundance and the standard morphodynamic indices, but significant relationships were found for both macro- and meiofaunal abundance when these indices were combined with an exposure index (derived from velocity, direction, duration and the effective fetch). All the relationships identified between abundance and combined morphodynamic indices indicated a higher abundance of both macro- and meiofauna on the more dissipative beaches. The reverse was however found for species richness. If predictions that accelerated sea-level rise will move beaches towards a more reflective morphodynamic state are correct, this could lead to declines in the abundance of meio- and macrofauna, with potential adverse consequences for ecosystem functioning.  相似文献   

Ecosystem-based management institutional design: Balance between federal,state, and local governments within the Gulf of Mexico Alliance     

Cristina Carollo  Dave J. Reed 《Marine Policy》2010

We present a case study of the organizational framework of the Gulf of Mexico Alliance (GOMA), which was implemented to promote the use of ecosystem-based management (EBM) at a regional level. GOMA is a state-led initiative formed to protect and restore coastal and marine resources of the Gulf of Mexico. Representatives of the US Gulf States, together with their federal partners, clearly defined ecological, social, and economic short- and long-term objectives to be reached through regional collaborations. The aim of this paper is to show how GOMA, and particularly the Ecosystem Integration and Assessment Priority Issue Team, in its attempt to apply ecosystem approaches to manage marine resources, modified the common organizational scheme by implementing partnerships at various governmental (federal, state, local) and nongovernmental levels. We address the following major points considered to be of importance for EBM implementation: (1) multilevel cooperation, (2) stakeholders’ involvement, (3) sharing of information, (4) bridging science and policy, and (5) consensus-based decision making.  相似文献   

Modelling and mass balance assessments of nutrient retention in a seasonally-flowing estuary (Swan River Estuary,Western Australia)     

Barbara J. Robson  Paul A. Bukaveckas  David P. Hamilton 《Estuarine, Coastal and Shelf Science》2008

An integrated mass balance and modelling approach for analysis of estuarine nutrient fluxes is demonstrated in the Swan River Estuary, a microtidal system with strong hydrological dependence on seasonal river inflows. Mass balance components included estimation of gauged and ungauged inputs to the estuary and losses to the ocean (outflow and tidal exchange). Modelling components included estimation of atmospheric (N fixation, denitrification) and sediment–water column nutrient exchanges. Gross and net denitrification derived using two independent methods were significantly correlated (r² = 0.49, p < 0.01) with net rates averaging 40% of gross. Annual nitrogen (N) and phosphorus (P) loads from major tributaries were linearly correlated with annual freshwater discharge and were 3-fold higher in wet years than in dry years. Urban drains and groundwater contributed, on average, 26% of N inputs and 19% of P inputs, with higher relative contributions in years of low river discharge. Overall, ungauged inputs accounted for almost 35% of total nitrogen loads. For N, elevated loading in wet years was accompanied by large increases in outflow (7x) and tidal flushing (2x) losses and resulted in overall lower retention efficiency (31%) relative to dry years (70%). For P, tidal flushing losses were similar in wet and dry years, while outflow losses (4-fold higher) were comparable in magnitude to increases in loading. As a result, P retention within the estuary was not substantially affected by inter-annual variation in water and P loading (ca. 50% in all years). Sediment nutrient stores increased in most years (remineralisation efficiency ca. 50%), but sediment nutrient releases were significant and in some circumstances were a net source of nutrients to the water column.  相似文献