Studies of the dC of pore water dissolved inorganic carbon (dC-DIC) were carried out in shallow water carbonate sediments of the Great Bahamas Bank (GBB) to further examine sediment–seagrass relationships and to more quantitatively describe the couplings between organic matter remineralization and sediment carbonate diagenesis. At all sites studied dC-DIC provided evidence for the dissolution o...

Faecal contamination of estuarine and coastal waters can pose a risk to human health, particularly in areas used for shellfish production or recreation. Routine microbiological water quality testing highlights areas of faecal indicator bacteria (FIB) contamination within the water column, but fails to consider the abundance of FIB in sediments, which under certain hydrodynamic conditions can be...

[1] Phosphorus (P) fractionation and distribution in sediments are of great concern in the Florida Everglades ecosystem because potential eutrophication of surface waters usually results from P external loading and stability. Intact core sediment samples were collected to a depth of 35 cm from wetlands and canals across Water Conservation Area 3 (WCA‐3) of the Florida Everglades. These sediment...

In sediments with oxidized surface layers, the percentage of mineralized nitrogen that is nitrified/ denitrified, compared with that released directly as ammonium, appears to be affected by the presence of sea salts. In estuarine systems, a significant portion of the nitrogen is released as ammonium, whereas in freshwater systems, most of the mineralized nitrogen is often released from the sedi...

Everglades sediments (wetland soils) near sources of agricultural runoff had low redox potentials, were blackened with sulfide, and displayed high porewater phosphorus (total) concentrations and high water column conductivities. These sediments yielded 10(sup3)- to 10(sup4)-fold-higher numbers of culturable anaerobes, including methanogens, sulfate reducers, and acetate producers, than did sedi...

The purpose of this paper was to compare two methods of fractionation of reactive phosphorus forms (RP) in bottom sediments of polymictic water reservoirs located in rural areas. As a criterion for estimation, quantities RP extracted in analyzed fractions versus the general content of Al, Fe and Ca were used. The sediments were collected in springtime, from rural areas with different land use i...

Methanogens are implicated in the production of methane that accumulates in marine sediments. However, the factors that control the distribution of the microbial communities that influence the presence of methane in these sediments are not well understood. Our objective is to determine the quantity, diversity, and distribution of microbial communities in the context of abiotic (e.g., grain size...

Anaerobic ammonium oxidizing (anammox) bacterial community structures were investigated in surface (1-2 cm) and lower (20-21 cm) layers of mangrove sediments at sites located immediately to the mangrove trees (S0), 10 m (S1) and 1000 m (S2) away from mangrove trees in a polluted area of the Pearl River Delta. At S0, both 16S rRNA and hydrazine oxidoreductase (HZO) encoding genes of anammox bact...

Clay-rich sediments from the Kajjansi, Kitiko, Kitetika, and Ntawo valleys in central Uganda were analyzed for mineralogical and chemical composition, including the rare earth element (REE) contents. The valleys are filled with Quaternary to Recent alluvial and lacustrine sands, silt, and gravels, which formed from the bed rock metasediments of the Buganda-Toro System and from granitoid rocks t...

Contaminated sediments contain a variety of volatile and semi-volatile hydrocarbons, which are released into the air, when these sediments are stored in confined disposal facilities (CDFs). Polycyclic aromatic hydrocarbons (PAHs) are one class of sediment contaminants that of great interest, since they are carcinogenic and pose a significant health hazard. Hence quantitative data and models are...