نتایج جستجو برای: marine sediments

تعداد نتایج: 116648  

2000
R. F. Chen

Chlorophyll degradation products are preserved in marine sediments over timescales of thousands of years. The production of chlorophyll in the water column is related to biological productivity, so chlorophyll degradation products (chlorins) preserved in marine sediments can be used as indicators of paleoproductivity. A new, rapid, nondestructive method of determining chlorin concentrations in ...

2015
Gordon Webster Louise A. O'Sullivan Yiyu Meng Angharad S. Williams Andrea M. Sass Andrew J. Watkins R. John Parkes Andrew J. Weightman

Archaea are widespread in marine sediments, but their occurrence and relationship with natural salinity gradients in estuarine sediments is not well understood. This study investigated the abundance and diversity of Archaea in sediments at three sites [Brightlingsea (BR), Alresford (AR) and Hythe (HY)] along the Colne Estuary, using quantitative real-time PCR (qPCR) of 16S rRNA genes, DNA hybri...

Journal: :Applied and environmental microbiology 2000
S C Nold J Zhou A H Devol J M Tiedje

The diversity of ammonia-oxidizing bacteria in aquatic sediments was studied by retrieving ammonia monooxygenase and methane monooxygenase gene sequences. Methanotrophs dominated freshwater sediments, while beta-proteobacterial ammonia oxidizers dominated marine sediments. These results suggest that gamma-proteobacteria such as Nitrosococcus oceani are minor members of marine sediment ammonia-o...

Journal: :Marine pollution bulletin 2007
Virginia Garrison Kevin Kroeger Douglas Fenner Peter Craig

hydrocarbons (PAHs) in coastal marine sediments: case studies in Cotonou (Benin) and Aquitaine (France) areas. Marine Pollution Bulletin 40, 387–396. Steinhauer, M.S., Boehm, P.D., 1992. The composition and distribution of saturated and aromatic hydrocarbons in near shore sediments, river sediments, and coastal peat of Alaskan Beaufort Sea: implications for detecting anthropogenic hydrocarbon i...

1999
DAVID J. BURDIGE WILLIAM M. BERELSON KENNETH H. COALE JAMES MCMANUS KENNETH S. JOHNSON

Fluxes of dissolved organic carbon (DOC) from marine sediments represent a poorly constrained component of the oceanic carbon cycle that may affect the concentration and composition of DOC in the ocean. Here we report the first in situ measurements of DOC fluxes from continental margin sediments (water depths ranging from 95 to 3,700 m), and compare these fluxes with measured benthic fluxes fro...

2015
Anna Hanke Jasmine Berg Theresa Hargesheimer Halina E. Tegetmeyer Christine E. Sharp Marc Strous

In coastal marine sediments, denitrification and fermentation are important processes in the anaerobic decomposition of organic matter. Microbial communities performing these two processes were enriched from tidal marine sediments in replicated, long term chemostat incubations at 10 and 25°C. Whereas denitrification rates at 25°C were more or less stable over time, at 10°C denitrification activ...

Journal: :Applied and environmental microbiology 2002
Rebecca J Melcher Sabine E Apitz Barbara B Hemmingsen

Experiments were carried out to develop methods to generate well-characterized, polycyclic aromatic hydrocarbon (PAH)-spiked, aged but minimally altered sediments for fate, biodegradation, and bioavailability experiments. Changes in indigenous bacterial populations were monitored in mesocosms constructed of relatively clean San Diego Bay sediments, with and without exposure to gamma radiation, ...

Background: Land and water pollution by heavy metals is a universal issue. Although the pollution affects all countries, but its range and severity vary hugely. The pollution of the marine environment by heavy metals is a worldwide problem. Marine sediments can be sensitive indicators for monitoring contaminants in aquatic environments. Methods: The concentration of 10 elements (As, Cd, Cr, Cu...

2012
Alejandro H. Buschmann Alexandra Tomova Alejandra López Miguel A. Maldonado Luis A. Henríquez Larisa Ivanova Fred Moy Henry P. Godfrey Felipe C. Cabello

Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbu...

2017
Diego C. Franco Camila N. Signori Rubens T. D. Duarte Cristina R. Nakayama Lúcia S. Campos Vivian H. Pellizari

Microorganisms dominate most Antarctic marine ecosystems, in terms of biomass and taxonomic diversity, and play crucial role in ecosystem functioning due to their high metabolic plasticity. Admiralty Bay is the largest bay on King George Island (South Shetland Islands, Antarctic Peninsula) and a combination of hydro-oceanographic characteristics (bathymetry, sea ice and glacier melting, seasona...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید