نتایج جستجو برای: bottom sediment

تعداد نتایج: 94716  

Journal: :Environmental microbiology 2007
Hongchen Jiang Hailiang Dong Bingsong Yu Xinqi Liu Yiliang Li Shanshan Ji Chuanlun L Zhang

Previous investigations of the salinity effects on the microbial community composition have largely been limited to dynamic estuaries and coastal solar salterns. In this study, the effects of salinity and mineralogy on microbial community composition was studied by using a 900-cm sediment core collected from a stable, inland hypersaline lake, Lake Chaka, on the Tibetan Plateau, north-western Ch...

2008
Juha Niemistö Heidi Holmroos Zeynep Pekcan-Hekim Jukka Horppila

The relative contributions of sediment resuspension and external nutrient loading to seasonal fluctuations of the total nitrogen to total phosphorus (TN : TP) ratio in the water column of the shallow Kirkkojärvi basin were studied. In May, the TN : TP mass ratio was above 30, but it decreased to below 10 in July–August. In October, the ratio increased again. Water quality was regulated by exter...

2015
Claudio Stalder Agostina Vertino Antonietta Rosso Andres Rüggeberg Claudius Pirkenseer Jorge E. Spangenberg Silvia Spezzaferri Osvaldo Camozzi Sacha Rappo Irka Hajdas Sigal Abramovich

Cold-water coral (CWC) ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago). However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds F...

محمود شفاعی بجستان, , حسین صمدی بروجنی, , منوچهر فتحی مقدم, ,

Sedimentation and consolidation of cohesive sediments near the dam body can cause many problems such as clogging the bottom outlets and entering the sediments into the hydropower intakes. Flushing of these sediments through the bottom outlet will be successful only if the hydraulic conditions are designed according to the physical and mechanical properties of consolidated sediments. During the ...

2005
J. B. JONES

Fishers have been complaining about the effects of bottom trawl gear on the marine environment since at least the 14th century. Trawl gear affects the environment in both direct and indirect ways. Direct effects include scraping and ploughing of the substrate, sediment resuspension, destruction of benthos, and dumping of processing waste. Indirect effects include post-fishing mortality and long...

2018
Shu-Xian Yu Yun-Long Pang Yin-Chu Wang Jia-Lin Li Song Qin

The eutrophic Bohai Sea receives large amount of suspended material, nutrients and contaminant from terrestrial runoff, and exchanges waters with the northern Yellow Sea through a narrow strait. This coastal region provides an ideal model system to study microbial biogeography. We performed high-throughput sequencing to investigate the distribution of bacterial taxa along spatial and environmen...

2016
Rénald Belley Paul V. R. Snelgrove Philippe Archambault S. Kim Juniper

The upwelling of deep waters from the oxygen minimum zone in the Northeast Pacific from the continental slope to the shelf and into the Salish Sea during spring and summer offers a unique opportunity to study ecosystem functioning in the form of benthic fluxes along natural gradients. Using the ROV ROPOS we collected sediment cores from 10 sites in May and July 2011, and September 2013 to perfo...

2005
Douglas George Guy Gelfenbaum Giles Lesser Bob Barnard Steven Morrison Perry Lund

Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered the initial morphology of the basin. As part of the Deschutes River Estuary Restoration Feasibility Study, the United States Geological Survey (USGS) is modeling how tidal and storm processes will influence the river, lake and lower Budd Inlet should estuary restoration occur. Understand...

Journal: :Computers & Geosciences 2006
Guy Simpson Sébastien Castelltort

This paper presents a mathematical model coupling water flow and sediment transport dynamics that enables calculating the changing surface morphology through time and space. The model is based on the shallow water equations for flow, conservation of sediment concentration, and empirical functions for bed friction, substrate erosion and deposition. The sediment transport model is a non-capacity ...

Journal: :Applied and environmental microbiology 2001
J Zopfi T Kjaer L P Nielsen B B Jørgensen

Microsensors, including a recently developed NO3(-) biosensor, were applied to measure O(2) and NO3(-) profiles in marine sediments from the upwelling area off central Chile and to investigate the influence of Thioploca spp. on the sedimentary nitrogen metabolism. The studies were performed in undisturbed sediment cores incubated in a small laboratory flume to simulate the environmental conditi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید