Auxin indole-3-acetic acid (IAA) was detected in marine sediments for the first time using HPLC and immunological identification methods. The IAA content of the interstitial water In sediments varied, in the order of I O ' ~ to 1 0 ~ m01 I ' , with sampling season and location. The content in seawater was much lower than that of sediments, ca 10-" to 10-l0 1no1 l-' Considerable amounts of IAA w...

Microbial communities and their associated metabolic activity in marine sediments have a profound impact on global biogeochemical cycles. Their composition and structure are attributed to geochemical and physical factors, but finding direct correlations has remained a challenge. Here we show a significant statistical relationship between variation in geochemical composition and prokaryotic comm...

Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable ...

concentrations of zn, cu, cr, cd, pb and fe in surface marine sediments of the southern coast of sfax were studied in order to understand current metal contamination at the outlet of a mixed industrial and domestic wastewater effluent discharged into the seawater since 1953. we found that heavy metal concentrations (mg/kg dry weight) in surface marine sediments varied from 42 to 391 for zn, 15 ...

concentrations of zn, cu, cr, cd, pb and fe in surface marine sediments of the southern coast of sfax were studied in order to understand current metal contamination at the outlet of a mixed industrial and domestic wastewater effluent discharged into the seawater since 1953. we found that heavy metal concentrations (mg/kg dry weight) in surface marine sediments varied from 42 to 391 for zn, 15 ...

The nature of Re–platinum-group element (PGE; Pt, Pd, Ir, Os, Ru) transport in the marine environment was investigated by means of marine sediments at and across the Cretaceous–Tertiary boundary (KTB) at two hemipelagic sites in Europe and two pelagic sites in the North and South Pacific. A traverse across the KTB in the South Pacific pelagic clay core found elevated levels of Re, Pt, Ir, Os, a...

The biological flux and lifetime of methanol in anoxic marine sediments are largely unknown. We herein reported, for the first time, quantitative methanol removal rates in subsurface sediments. Anaerobic incubation experiments with radiotracers showed high rates of microbial methanol consumption. Notably, methanol oxidation to CO2 surpassed methanol assimilation and methanogenesis from CO2/H2 a...

a r t i c l e i n f o Keywords: paleoceanography carbonate sedimentology aqueous geochemistry Observed changes in the source of CaCO 3 sediments since Archean time suggest a first order pattern of decreasing abundance of carbonate cements precipitated directly on the seafloor. We propose that the observed reduction in CaCO 3 precipitation on the seafloor is caused by a decrease in CaCO 3 satura...

[1] Magnitudes of terrestrial (fresh) and marine (saline) sources of submarine groundwater discharge (SGD) are estimated for a transect across Indian River Lagoon, Florida. Two independent techniques (seepage meters and pore water Cl concentrations) show terrestrial SGD decreases linearly to around 22 m offshore, and these techniques, together with a model based on the width of the outflow face...

The long-term goal of this study is to develop a better mechanistic and quantitative understanding of the effects of biologically-enhanced transport, mineralogy, sediment fabric, and particle surface chemistry on biogeochemical reactions occurring in coastal sediments. Specifically, we plan to provide quantitative expressions of biogeochemical processes from field and laboratory studies and to ...