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Sc and Sr were isolated from enrichment cultures using dimethyl isophthalate (DMI) as the sole carbon and energy source and mangrove sediment as an inoculum. Complete degradation of DMI required both species of bacteria at different biochemical transformation steps. The biochemical degradation pathway was DMI to monomethyl isophthalate (MMI) by Sc, MMI to isophthalate (IPA) by Sr, and IPA by both Sc and Sr sequentially. The consortium comprising of Sc and Sr was effective in complete degradation of DMI in eight days. Our results suggest that a consortium of microorganisms indigenous to the mangrove environment is responsible for mineralization of environmental pollutant DMI through biochemical cooperation.

Benthic infaunal communities at Mai Po Inner Deep Bay mudflat, Hong Kong were investigated between August 2002 and August 2003. A total of 55 species belonging to 8 Phyla from more than 99,074 specimens were recorded. The species richness varied between 13 at Station B in August 2002 and 28 at Station D in August 2003 with an average of 21 across the mudflat and the species diversity was low [′(log2) = 0.7–3.5 with an average ′ = 2.4]. Seasonal variations were also observed through abundance and biomass across the mudflat among the seasons. The abundance density was between 8,977 individuals m at Station D in February 2003 and 77,256 individuals m at Station B in November 2002 and the overall average density was 25,274 individuals m for the four stations. The benthic infauna were dominated by pollution tolerant species at this wetland mudflat.

Characterizing sorption processes is essential to understand the environmental distribution and toxicity potential of endocrine disruptors in terrestrial and aquatic systems. The sorption behaviors of three endocrine disruptors (bisphenol A (BPA), 17β-estradiol (E2), and 17α-ethynylestradiol (EE2)) on sediments were investigated using batch techniques. Samples were taken from some representative reaches in several major Chinese rivers. More attention has been paid to the effect of sediment organic components on the sorption of BPA, E2, and EE2. The results show that the sediment organic carbon-normalized partition coefficients ((sed)) for three endocrine disruptors are in the order of EE2 > E2 > BPA, which corresponds to the octanol-water partitioning coefficients (log) of the compounds. Moreover, the values for humic substances ((hs)) are comparable with the (sed) values and highly dependent on the physico-chemical properties of humic substances in sediments. The UV absorptivity at 272 nm (), which suggests the abundance of aromatic rings in humic substance structure, correlates well with the (hs) values. In addition, the infrared spectra of the humic substances extracted from sediments show four strong bands centered at 3,400 cm, 1,625 cm, 1,390 cm, and 1,025 cm. The (hs) values have a positive linear relation with the peak area ratio for peak at 1,025 cm and a negative linear relation with the peak area ratio between peaks at 1,625 cm and 1,025 cm. Hence, the hydrogen bonds play a critical role to the sorption of selected endocrine disruptors.

In the framework of the EUROSTRATAFORM projects, a multidisciplinary research was focused on processes that involve transport and deposition of riverine material in the Adriatic Sea. The aim of our contribution was to increase a more complete understanding of organic matter deposition on the Adriatic shelf, also taking into account the role of Apennine rivers beyond the Po influence. In order to characterize origin, fate and variability of sedimentary organic carbon we utilized elemental and stable carbon isotope data in surficial sediments along shallow cross-shelf transects on the western Adriatic shelf.

To reconstruct a history of polycyclic aromatic hydrocarbon (PAH) pollution in the Gulf of Trieste, one of the largest urbanized areas in the Adriatic Sea, we analyzed three long sediment cores collected between 1996 and 1997. Concentrations of total PAHs, the sum of 16 PAH compounds and six of their methylated analogues, in all three cores show a decrease from 600–800 ng g, at the surface, to levels below 250 ng g in deepest layers (down to 3 m). The same trend was shown with separate representative pyrogenic PAHs (pyrene, benzofluoranthene and phenanthrene). Using Hg as a recent geochronological tracer, we observe an increasing input of PAHs since the beginning of the 20th Century and, especially, after the Second World War coinciding with increasing industrialization and urbanization of the region. This correlation is supported by PAH ratios that are indication of combustion processes and represent a marker for anthropogenic inputs. No correlation exists between PAHs and black carbon within the core profiles, indicating two different fractions of the ‘black carbon continuum’.

Detailed information on post-logging sediment dynamics in tropical catchments is required for modelling downstream impacts on communities and ecosystems. Sediment tracing methods, which are potentially useful in extending to the large catchment scale and longer time scales, are tested in primary and selectively logged rainforest catchments of Sabah, Borneo. Selected nutrient (P and N) and trace metal (Ni and Zn) concentrations are shown to discriminate surface, shallow subsurface and deep subsurface sediment sources. Analysis of channel-stored fine-sediment samples and use of an unmixing model allow the relative importance of these vertical sediment sources to be estimated and erosion processes to be inferred for catchments of contrasting size.

The holistic river basin approach of the European Water Framework Directive (WFD) requires the combined assessment of ecological risks and the development of remediation measures. This paper presents a three-step strategy for the assessment of risks on Rotterdam harbour arising from historical contaminated sediment in the Rhine river basin, by the identification of (1) substances of concern, (2) areas of concern and (3) areas of risk with regard to the probability of polluting the sediments in the downstream reaches. The pragmatic approach provides initial evidence, that sediment-associated hexachlorobenzene (HCB) from the Higher and Upper Rhine has a significant effect on the quality of dredged material from Rotterdam harbour and that this HCB contamination is a candidate for the Category 1 of WFD Article 16 Source/Pathway S.11.1 ‘Historical Pollution from Sediments’: This HCB source can contribute to a failure of the objectives of the WFD in the Rhine Basin and may require additional measures for its control.

This paper describes a study examining the potential of mineral magnetic, geochemical and organic properties to determine if a 2003 wildfire in a catchment in British Columbia, Canada, caused a change in the sources of the suspended sediment transported in the channel relative to a nearby unburnt (reference) catchment. The results show that some of the properties offer the potential to determine sediment sources in the unburnt catchment. However, the 2003 wildfire modified the concentrations of some properties and this can either compromise or enhance their ability as tracers in the burnt catchment. At present, the source tracing results are inconclusive. This has implications for the use of certain properties as fingerprints and raises important issues about approaches to sediment source identification.

In August of 2003 a severe wildfire burnt the majority of Fishtrap Creek, a 170 km catchment in central British Columbia, Canada. The objective of this study was to determine the short-term (15-month) influence of the wildfire on the amount and composition of fine sediment delivery and retention in the system and to compare it to a similar unburnt catchment. In the spring of 2004 automatic water samplers were installed at a gauging site on Fishtrap Creek to collect suspended sediments from the snowmelt runoff and gravel traps were deployed on the channel bed surface to collect composite samples of suspended fine sediment. Jamieson, the reference creek, exhibits similar geology and pre-burn vegetation and was sampled in the same manner for comparison. Composite suspended sediment collected in the traps was removed from the streams in mid-summer and early September. Quantitative estimates of the amount and particle size structure of the naturally stored fine sediment in, and on, the gravel creekbed were obtained in pre-melt, mid and late-summer conditions. Estimates of suspended sediment yields indicated that while the burnt system delivered 66% more material per unit area, the total seasonal suspended sediment yield was low (855 kg km) compared to other fire-disturbed systems. While the burnt catchment was primed to deliver sediment, the hydrologic drivers were not of sufficient magnitude to generate a substantial response, suggesting that in this first post-fire year the system was transport-limited, not supply-limited. Differences were noted in the spatial and seasonal composition of the <500 µm composite suspended sediments, with the burnt catchment having significantly (≤0.05) more OM%. Seasonally a significant increase of OM% in late summer samples was associated with instream biofilms and possible delivery of black carbon. The system’s post-fire response was not geomorphically substantial but significant biological differences were noted in the short-term.

Soil erosion and associated off-site environmental impacts have attracted increasing attention in recent decades, and there is a growing need for reliable information on rates of soil loss. The potential for using Cs fallout to quantify rates and patterns of soil redistribution over medium-term timescales (ca. 45 years) has been successfully demonstrated in a wide range of environments around the world. The similar behaviour of fallout Pb in soils offers potential for its use as an alternative to Cs, in areas where Cs inventories are low or are complicated by additional fallout from the Chernobyl accident. There have, however, to date been few attempts to validate the use of fallout Pb measurements for assessing erosion rates. This paper reports an attempt to explore the use of fallout Pb to estimate rates of water-induced soil erosion on uncultivated land. It focuses on three small forest/rangeland catchments located in Calabria, southern Italy, for which measurements of sediment output are available. Comparison of the estimates of net soil loss from the catchments derived from Pb measurements with the measured sediment output, confirmed the validity of the Pb approach. The soil redistribution rates estimated using Pb measurements were also consistent with equivalent estimates obtained for the same study catchments using Cs measurements.