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The temporal-spatial distribution of the carbon and nitrogen contents and their isotopic compositions of suspended matter and sediments from the Yellow River estuary reach (YRER), the estuary to the offshore area were measured to identify the source of organic matter. The higher relative abundances of suspended and sedimentary carbon and nitrogen (POC, TOC, PN and TN) in the offshore marine area compared to those of the riverine and estuarine areas may be due to the cumulative and biological activity impact. The organic matter in surface sediments of YRER, the estuary and offshore area of Bohai Sea is basically the mixture of continental derived material and marine material. The values of δ 13 C sed fluctuate from values indicative of a land source (− 22.50‰ ± 0.31) to those indicative of a sea source (− 22.80‰ ± 0.38), which can be attributed to the fine particle size and decrease in terrigenous inputs to the offshore marine area. Contrary to the slight increase of POC and PN during the dry season, TOC and TN contents of the surface sediments during the flood season (October) were higher than those during the dry season (April). The seasonal differences in water discharge and suspended sediment discharge of the Yellow River Estuary may result in seasonal variability in TOC, POC, TN and PN concentrations in some degree. Overall, the surface sediments in the offshore area of Bohai Sea are dominated by marine derived organic carbon, which on average, accounts for 58–82% of TOC when a two end-member mixing model is applied to the isotopic data. [ABSTRACT FROM AUTHOR]

Un-restored (R 0) and restored (in 2006 (R 2006) and in 2002, (R 2002)) coastal wetlands were selected to study phosphorus (P) storage capacity and the risk of P loss in the Yellow River Delta (YRD). The results showed that the maximum P sorption capacity (Q max) in the wetland sediments varied between 201.8–1168.6 mg kg−1; the average value was 576.2 mg kg−1. Q max increased with increasing time since restoration (R 2002 > R 2006 > R 0). The eutrophication risk index (ERI) ranged between 0.27–2.07% and decreased with increasing time since restoration, but the relationship was not statistically significant (P > 0.05). A correlation analysis demonstrated that Fe ox , Mg, and Al ox are the main P sorption agents in wetland sediments, whereas TOC, pH, and clay particles have an important effect on P sorption and release. The analysis suggests that we should restore degraded coastal wetlands to help reduce the P load to offshore waters. • Phosphorus sorption increased with coastal wetland restoration in Yellow River Delta, China. • T he Fe ox 、Mg、and Al ox content dominanted phosphorus sorption in Yellow River Delta sediments. • Restored wetlands can be used for phosphorus reduction at coastal zone. [ABSTRACT FROM AUTHOR]

Abstract: Sea cucumbers are regarded as traditional, delicious and luxurious seafood in Asia. Generally, it is difficult for species identification of sea cucumbers based on morphological characterization. In this study, Multiplex-PCR was developed to identify four sea cucumber species (Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, and Parastichopus californicus). After constructing the 692bp fragments of mitochondrial cytochrome oxidase I (COI) gene, four sets of species-specific primer were designed. The amplified lengths of fragments were 212bp for A. japonicus, 301bp for C. frondosa, 261bp for T. ananas and 358bp for P. californicus respectively, which could be obviously differentiated on DNA electrophoresis. The four sets of species-specific primer were mixed and applied to detect sea cucumber species simultaneously. Therefore, multiplex-PCR provided a convenient, useful, specific and academic technique to authenticate the sea cucumber species. This methodology can be very useful for traceability of sea cucumber species. [Copyright &y& Elsevier]

Nine units in new-born intertidal zone of the Yellow River estuary, China were examined for concentrations of heavy metals (Pb, Cr, Cu, Zn and Ni) in sediments and plants. Heavy metal levels in surface sediments were in the order of Zn > Pb ≈ Cr > Cu ≈ Ni and generally increased in a seaward direction except for Z6 ( Tamarix chinensis - Suaeda salsa zone) and Z7 ( S. salsa - T. chinensis zone) units. Significant differences in metal concentrations of the 9 units were observed in the profiles ( p < 0.01). Heavy metal levels in the shoots or roots of different plants decreased in the order of Zn > Cu > Pb > Ni > Cr and differed among plants or tissues. The roots at Z2 ( Calamagrostis pseudophragmites zone), Z3 ( Imperata cylindrical zone) and Z4 ( Phramites australis zone) units accumulated greater metals than shoots [TFs (translocation factors) < 1], while the shoots at Z1 ( Sparganium minimum - Potentilla supina zone), Z7 and Z8 ( S. salsa zone) units accumulated greater metals than roots (TFs > 1), implying that intertidal plants showed different pathways in metal accumulation and internal transportation. Except for Pb, the concentrations of Cr, Cu, Zn and Ni in sediments were lower than the criteria of Class I recommended by the Environmental Quality Standard for Soils of China. Although heavy metal levels in intertidal zone were generally the lowest (Cr, Cu, Zn and Ni) or relatively moderate (Pb) compared with other estuaries or bays in Asia and Europe, high eco-toxic risk of Pb and Ni exposure still could be observed at Z4, Z6 and Z9 (mudflat zone) units. S. salsa was more suitable for the potential biomonitor or phytoremediation of all five heavy metals if intertidal sediments was seriously contaminated with increasing of pollutants loading in the Yellow River estuary. [ABSTRACT FROM AUTHOR]