The burial of organic carbon in marine sediments removes carbon dioxide from the ocean-atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we s...

Species diversity, phylogenetic affiliations, and environmental occurrence patterns of thiosulfate-oxidizing marine bacteria were investigated by using new isolates from serially diluted continental slope and deep-sea abyssal plain sediments collected off the coast of New England and strains cultured previously from Galapagos hydrothermal vent samples. The most frequently obtained new isolates,...

middle-late eocene deep marine deposits (483 m.) of the islam-ghaleh section, south mashhad, rich in ichnofossils in shale and sandstone layers. these flysch type sediments are composed of sandstone, shale and marl in gray to green in color and are divided into five subunits. the lower boundary of these successions is gradual with red conglomerate and sandstone and their upper boundary is gradu...

Phylogenetic analysis of 16S rRNA gene sequences from deep marine sediments identified a deeply branching clade, designated candidate division JS1. Primers for PCR amplification of partial 16S rRNA genes that target the JS1 division were developed and used to detect JS1 sequences in DNA extracted from various sedimentary environments, including, for the first time, coastal marine and brackish s...

The short chain, gaseous alkanes ethane, propane, n- and iso-butane are released in significant amounts into the atmosphere, where they contribute to tropospheric chemistry and ozone formation. Biodegradation of gaseous alkanes by aerobic microorganisms, mostly bacteria and fungi isolated from terrestrial environments, has been known for several decades. The first indications for short chain al...

[1] It has been suggested that much of the observed glacial-interglacial variability in the atmospheric mixing ratio of CO2 (xCO2) could potentially be driven by a perturbation of the marine Si cycle. To date, only relatively simple steady-state analysis has been made of this hypothesis. In this study, we develop a description of the ocean carbon cycle, incorporating novel descriptions for the ...

Sediment internal nitrogen release is a significant pollution source in the overlying water of aquatic ecosystems. This study aims to remove internal nitrogen in sediment-water microcosms by coupling sediment microbial fuel cells (SMFCs) with submerged aquatic plants. Twelve tanks including four treatments in triplicates were designed: open-circuit (SMFC-o), closed-circuit (SMFC-c), aquatic pla...

Biological criteria for defining water quality and the presence of acceptable levels of benthic resources are evaluated for estuarine macrobenthic communities of the lower Chesapeake Bay, USA. Models of expected community values as a function of salinity are presented for community biomass, numbers of individuals, species richness, percent biomass of deep-dwelling species, percent biomass of eq...

Sediment bacteria play important roles in the biogeochemistry of ocean sediments; however, factors influencing assemblage composition have not been extensively studied. We examined extractable sediment bacterial abundance, the composition of bacterial assemblages using a high-throughput molecular fingerprinting approach, and several sediment biogeochemical parameters (organic matter content and...

The deep subseafloor biosphere is among the least-understood habitats on Earth, even though the huge microbial biomass therein plays an important role for potential long-term controls on global biogeochemical cycles. We report here the vertical and geographical distribution of microbes and their phylogenetic diversities in deeply buried marine sediments of the Pacific Ocean Margins. During the ...