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991.
Beach nourishment is increasingly being implemented to address problems of erosion. However, the ecological consequences of nourishment are poorly understood, especially in Australia. In Botany Bay, sand was piped from an intertidal borrow area at Elephant's Trunk to nourish the nearby eroding beach at Towra Point. The effects on an intertidal exoedicerotid amphipod, Exoediceros fossor (Stimpson, 1856), were examined using a beyond-BACI (Before–After, Control–Impact) sampling design. Sampling was conducted before and after engineering operations at sites within the borrow and nourishment locations and multiple control locations. Hypotheses concerning impact and recovery were tested using asymmetrical ANOVAs and two-tailed F-tests. These examined the effects on abundance and spatial variability, respectively. The impact of the engineering operations on abundance was very large at both borrow and nourishment locations. However, recovery started within several weeks and, using space × time interactions as a criterion, appeared to be complete within a year. This conclusion is made cautiously because of low statistical power and because other criteria for recovery suggest that it was not complete at some sites. As beach erosion is likely to increase in severity with rising sea levels and greater storm surges associated with climate change, management authorities will need a better understanding of the ecological effects of beach nourishment. 相似文献
992.
P.R. Dando A.J. Southward E.C. Southward P. Lamont R. Harvey 《Deep Sea Research Part I: Oceanographic Research Papers》2008,55(8):966-996
The small frenulate pogonophores (Annelida: Pogonophora a.k.a. Siboglinidae) typically inhabit muddy sediments on the continental slope, although a few species occur near hydrothermal vents and cold seeps. We present data on the distribution and habitat characteristics of several species on the European continental shelf and slope from 48°N to 75°N and show how the animals interact with the chemistry of the sediments. The environments inhabited include: shallow (30 m), organic-rich, fjord sediments; slope sediments (1000–2200 m) and methane seeps at 330 m depth. All the species studied obtain nutrition from endosymbiotic bacteria. They take up reduced sulphur species, or in one case, methane, through the posterior parts of their tubes buried in the anoxic sediment. We conclude that most species undertake sulphide ‘mining’, a mechanism previously demonstrated in the bivalves Lucinoma borealis and Thyasira sarsi. These pogonophores participate in the sulphur cycle and effectively lower the sulphide content of the sediments. Our results show that the abundance of frenulate pogonophores increases with increasing sedimentation and with decreasing abundance of other benthos, particularly bioturbating organisms. The maximum sustainable carrying capacity of non-seep sediments for frenulate pogonophores is limited by the rate of sulphate reduction. 相似文献
993.
E. F. Mikhailov S. S. Vlasenko T. I. Ryshkevich 《Izvestiya Atmospheric and Oceanic Physics》2008,44(4):416-431
The hygroscopic properties of a model smoke aerosol series including ammonium sulfate, levoglucosan, and oxalic and humic acids were investigated. The condensation growth of particles and the relative humidity of direct and inverse particle-droplet phase transitions were measured with a tandem differential mobility analyzer. The data were obtained in the range of relative humidity from 4 to 95% at 298 K. Experimental growth factors were compared to the results of Koehler theory by using contemporary models of water activity in particles. It was shown that the hygroscopic properties of the aerosols were substantially different from the hygroscopic properties of the corresponding bulk phases. It was found that a complex microstructure of nanoparticles resulted in excess volume absorption of water, in some cases causing their full deliquescence at lower relative humidities than in macrosystems of identical composition. From the measurement data, a parametrization of hygroscopic particle growth was performed. The results of parametrization can be used to construct refined models of a smoke aerosol. 相似文献
994.
Oceanology - On cruise 76 in 2019, the R/V Akademik Mstislav Keldysh completed the Gulf of Ob–Kara Sea slope transect. Samples of bottom water and two sediment layers 1 cm thick were obtained... 相似文献
995.
Krek A. V. Krek E. V. Ezhova E. E. Paka V. T. Kondrashov A. A. Danchenkov A. R. Bagirov N. E. Kudryavtzeva E. A. Bubnova E. S. Sergeev A. Yu. Aleksandrov S. V. 《Oceanology》2021,61(4):581-583
Oceanology - New data on the structure of the water column, upper layer of bottom sediments, and biological communities of the Gdansk and Gotland deeps and the Gulf of Finland in the Baltic Sea... 相似文献
996.
Demidov A. B. Gagarin V. I. Eremeeva E. V. Artemiev V. A. Polukhin A. A. Shchuka S. A. Grigoriev A. V. Khrapko A. N. Flint M. V. 《Oceanology》2021,61(5):645-661
Oceanology - Spatial and vertical variability of primary production (PP) and Chl a were studied in the framework of the 76th cruise of R/V Akademik Mstislav Keldysh to the Kara Sea from July 7 to... 相似文献
997.
Zhmur V. V. Novoselova E. V. Belonenko T. V. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(6):632-641
Izvestiya, Atmospheric and Oceanic Physics - The potential vorticity (PV) in the ocean is considered, including the history of the term. Various aspects and basic formulas used to calculate the PV... 相似文献
998.
A. A. Zhamaletdinov A. N. Shevtsov E. P. Velikhov A. A. Skorokhodov V. E. Kolesnikov T. G. Korotkova P. A. Ryazantsev B. V. Efimov V. V. Kolobov M. B. Barannik P. I. Prokopchuk V. N. Selivanov Yu. A. Kopytenko E. A. Kopytenko V. S. Ismagilov M. S. Petrishchev P. A. Sergushin P. E. Tereshchenko B. V. Samsonov M. A. Birulya M. Yu. Smirnov T. Korja Yu. M. Yampolski A. V. Koloskov N. A. Baru S. V. Poljakov A. V. Shchennikov G. I. Druzhin W. Jozwiak J. Reda Yu. G. Shchors 《Izvestiya Atmospheric and Oceanic Physics》2015,51(8):826-857
999.
Reservoir potential of Late Cretaceous terrestrial to shallow marine sandstones,Taranaki Basin,New Zealand 总被引:2,自引:0,他引:2
Late Cretaceous coals and coaly source rocks are the main source of hydrocarbons in the Taranaki Basin, yet to date there have not been any hydrocarbon discoveries within Cretaceous strata, and sandstone distribution and reservoir quality for this interval have been poorly understood. The Late Cretaceous sediments were deposited in several sub-basins across Taranaki, with their distribution largely determined by sediment supply, subsidence, and sea level change. In this study, we describe potential reservoir facies in well penetrations of Cretaceous strata in Taranaki, as well as from outcrop in northwest Nelson, on the southern edge of the basin. 相似文献
1000.
E. González-Ortegón M.D. Subida J.A. Cuesta A.M. Arias C. Fernández-Delgado P. Drake 《Estuarine, Coastal and Shelf Science》2010
Estuaries are used as nursery grounds by numerous marine species despite being usually subject to strong anthropogenic disturbances. Abundances of marine recruits (fish and crustacean decapods) and their main prey (mysids) were monitored by monthly sampling, from June 1997 to February 2009, in the lower reaches of the Guadalquivir estuary (SW Spain). During that period, unusually high and persistent turbidity events (HPTEs) were observed twice. Both HPTEs started with strong and sudden freshwater discharges after relatively long periods of very low freshwater inflow. Data from this time-series were used to test the hypothesis that HPTEs may negatively impact the nursery function of estuaries either by decreasing prey availability or by decreasing survival/arrival of marine recruits. During HPTEs, the commonest mysid (Mesopodopsis slabberi), a key species in the estuarine food web, showed a significant decrease in abundance. Likewise, some marine recruits that prey on M. slabberi and whose peaks of abundance within the estuary occur in summer–autumn (Engraulis encrasicolus and Pomadasys incisus) were less abundant during HPTEs. It is also suggested that HPTEs might have triggered a shift in the distribution of the most euryhaline prey (Neomysis integer) and predator (Dicentrarchus punctatus and Crangon crangon) species, towards more saline waters. This could have contributed to an increase in the inter-specific competition (for food/habitat) within the estuarine nursery area. The results discussed in this study call attention to the need to reduce as much as possible the anthropogenic pressures that may stimulate the occurrence of high and persistent turbidity events (HPTEs) in order to preserve the nursery function of temperate estuaries. 相似文献