Oxygen deficiency in the near-bottom water associated with eutrophication has been shown to have negative impacts on marine benthos in many Scandinavian waters. In the present study, the benthic fauna and the sedimentary habitat have been studied between 7 and 34 m depth; at 14 stations in three Swedish fjords in four different years, and at 12 stations along the Swedish coast in three differen...

In this paper we study the propagation of acoustic waves in two dimensional oceans with porous-elastic seabeds. First we outline our results developed for three dimensional ocean with rigid bottom and a depth dependent index of refraction. Then we extend this problem to an ocean bed consisting of porous, elastic sediment, lying over an elastic rock substrata.

Fecal coliform concentrations increased significantly (F test) in the immediate vicinity of a maintenance dredging operation in the Mississippi River navigation channel. Increased counts were attributed to the disturbance and relocation of bottom sediments by dredging and a concomitant release of sediment-bound fecal coliforms.

A thorough knowledge of sedimentary processes that cause the production, transportation and deposition in varied hydrodynamic conditions, is most important in environmental reconstruction. Size analysis of sediment is an essential requirement to understand their mechanism of transportion and deposition. Textural parameters are primarily related to made of transportation and energy condition of ...

Sedimentary phosphorus sPd composition was investigated in Effingham Inlet, a fjord located on the west coast of Vancouver Island in Barkley Sound. Solid-state P nuclear magnetic resonance sNMRd spectroscopy was applied to demineralized sediment samples from sites overlain by oxic and anoxic bottom waters. The two sites were similar in terms of key diagenetic parameters, including the mass accu...

Filter-feeding molluscan shellfish can concentrate zoonotic and anthroponotic waterborne pathogens. Cysts of Giardia sp. were detected by immunofluorescent antibodies in tissues of the clams Macoma balthica and M. mitchelli from Rhode River, a Chesapeake Bay (Maryland) subestuary. Molecular tests identified the cysts as Giardia duodenalis Genotype A, the most common genotype recovered from huma...

Lake Towuti is a tectonic basin, surrounded by ultramafic rocks. Lateritic soils form through weathering and deliver abundant iron (oxy)hydroxides but very little sulfate to the lake and its sediment. To characterize the sediment biogeochemistry, we collected cores at three sites with increasing water depth and decreasing bottom water oxygen concentrations. Microbial cell densities were highest...

A study of the ecotoxicological quality of surface sediment was carried out on samples collected in the main fjords and interior channels between Reloncaví and Corcovado gulfs. The surface sediment samples were taken with a box corer and analyzed for organic matter content and grain size. Dissolved oxygen was measured in water samples taken 10 m off the bottom. The ecotoxicological evaluation o...

Acoustic bottom-interacting measurements from the Shallow Water '06 experiment experiment (frequency range 1-20 kHz) are presented. These are co-located with coring and stratigraphic studies showing a thin (approximately 20 cm) higher sound speed layer overlaying a thicker (approximately 20 m) lower sound speed layer ending at a high-impedance reflector (R reflector). Reflections from the R ref...

We want to look at the dynamics of the coherent vortex structures which are generated at the bottom of sea waves by 1) the instability of the laminar boundary layer and the development of turbulence, 2) the nonlinear interaction of the oscillatory boundary layer with a wavy bed of small amplitude and with a sloping bottom and 3) the separation of the boundary layer at the crests of 2-D ripples ...