Unprecedented development along tropical shorelines is causing severe degradation of coral reefs primarily from increases in sedimentation. Sediment particles smother reef organisms and reduce light available for photosynthesis. Excessive sedmentation can adversely affect the structure and function of the coral reef ecosystem by altering both physical and biological processes. Mean sediment rat...

Survival and settlement of Pocillopora damicornis larvae on hard surfaces covered with fine (<63 µm) terrigenous red clay was measured in laboratory Petri dishes. The dishes were prepared with sediment films of various thicknesses covering the bottoms. Coral larvae were incubated in the dishes for two weeks and the percent that settled on the bottom was determined. There was a statistically sig...

BACKGROUND Sorption and biodegradation are the primary processes of organic pollution remediation in aquatic and soil/sediment environments. While researchers have substantially reported their findings regarding these processes, little attention has been given to description of experimental apparatus. This technical paper aims to present the development and detailed design of a fixed-bed column...

The vast marine deep biosphere consists of microbial habitats within sediment, pore waters, upper basaltic crust and the fluids that circulate throughout it. A wide range of temperature, pressure, pH, and electron donor and acceptor conditions exists-all of which can combine to affect carbon and nutrient cycling and result in gradients on spatial scales ranging from millimeters to kilometers. D...

Accumulations of sediment beneath the Antarctic Ice Sheet contain a range of physical and chemical proxies with the potential to document changes in ice sheet history and to identify and characterize life in subglacial settings. Retrieving subglacial sediments and sediment cores presents several unique challenges to existing technologies. This paper briefly reviews the history of sediment sampl...

An ~1:1 mixture of ferrihydrite and nanocrystalline akaganeite (β-FeOOH; 10–15 nm) was incubated with Shewanella putrefaciens (strain CN32) under anoxic conditions with lactate as an electron donor and anthraquinone-2,6-disulfonate (AQDS) as an electron shuttle. The incubation was carried out in a 1,4-piperazinediethanesulfonic acid (PIPES)-buffered medium, without PO4 at circumneutral pH. Iron...

Neoproterozoic carbon isotope excursions are commonly attributed to changes in the global fraction of organic burial associated with climate instability and/or oxygenation. Here we show that carbonate sediment deposited during ca. 661 – <651 Ma Cryogenian non-glacial interlude between Sturtian and Marinoan glaciations exhibit lateral offsets carbonate-carbon values from coeval units by as much ...

Arsenic (As) fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment samples of lakes of the East Plain Lake Ecoregion are higher than those of Yungui Plateau Lake Ecoregion. Residual As is the main fraction in sediment samples of lakes from both ecor...

The response of coccolithophore calcification to ocean acidification has been studied in culture experiments as well as in present and past oceans. The response, however, is different between species and strains, and for the relatively small carbonate chemistry changes observed in natural environments, a uniform response of the entire coccolithophore community has not been documented so far. Mo...

erosion and sediment movement phenomena are one of the most complex issues in management of rivers drainage areas that in water projects are very important. that its measurement wants high time and cost. issue of surface runoff in river basin is a complex issue that human knowledge and understanding about its physical laws a viewpoint of some mathematical formulas is limited. in this study to i...