Eco-Environmental Impact Assessment of Pre-Leisure Beach Nourishment on the Benthic Invertebrate Community at Anping Coast

In recent years, owing to global warming and the rising sea levels, beach nourishment and groin building have been increasingly employed to protect coastal land from shoreline erosion. These actions may degrade beach habitats and reduce biomass and invertebrate density at sites where they were employed. We conducted an eco-environmental evaluation at the Anping artificial beach-nourishment project area. At this site, sand piles within a semi-enclosed spur groin have been enforced by use of eco-engineering concepts since 2003. Four sampling sites were monitored during the study period from July 2002 to September 2008. The environmental impact assessment and biological investigations that we conducted are presented here. The results from this study indicate that both biotic （number of species, number of individual organisms, and Shannon-Wiener diversity） and abiotic parameters （suspended solids, biological oxygen demand, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, total phosphorus, total organic carbon, median diameter, and water content） showed significant differences before and after beach engineering construction. Biological conditions became worse in the beginning stages of the engineering but improved after the restoration work completion. This study reveals that the composition of benthic invertebrates changed over the study period, and two groups of organisms, Bivalvia and Gastropoda, seemed to be particularly suitable to this habitat after the semi-enclosed artificial structures completion.

Coupling interaction between biodiversity and aquatic habitat area in Western Route Project vicinity

The Western Route of the South-to-North Water Transfer Project will divert water from the upper Yangtze River and its tributaries, the Dadu River and Yalong River, to the upper Yellow River. The project may ease the water shortage in the Yellow River Basin. However, it may also have some effects on the ecosystem in the upper Yangtze River Basin. Benthic invertebrates play an important role in the river ecosystem, particularly in the circulation of materials and nutrition. Benthic invertebrates are widely used to quickly assess river ecosystems because of their rapid response to changes in the water environment. The diversity of benthic invertebrates is closely associated with the aquatic habitat area. This study examined this interaction by sampling the benthic invertebrates in an expanding area. The conclusions are that the diversity of benthic invertebrates begins to decrease when the aquatic habitat area is reduced to 45% of the original area, and decreases dramatically when the aquatic habitat area is reduced to 10% of the original area. The aquatic habitat area should be kept at more than 45% of the original area in order to maintain the significant diversity of benthic invertebrates.

Bioaccumulation and effects of sediment-associated gold-and graphene oxide nanoparticles on Tubifex tubifex

With the development of nanotechnology,gold（Au） and graphene oxide（GO） nanoparticles have been widely used in various fields,resulting in an increased release of these particles into the environment.The released nanoparticles may eventually accumulate in sediment,causing possible ecotoxicological effects to benthic invertebrates.However,the impact of Au-NPs and GO-NPs on the cosmopolitan oligochaete,Tubifex tubifex,in sediment exposure is not known.Mortality,behavioral impact（GO-NP and Au-NP） and uptake（only Au-NP） of sediment-associated Au-NPs（4.9±0.14 nm） and GO-NPs（116±0.05 nm） to T.tubifex were assessed in a number of 5-day exposure experiments.The results showed that the applied Au-NP concentrations（10 and 60 μg Au/g dry weight sediment） had no adverse effect on T.tubifex survival,while Au bioaccumulation increased with exposure concentration.In the case of GO-NPs,no mortality of T.tubifex was observed at a concentration range of 20 and180 μg GO/g dry weight sediment,whereas burrowing activity was significantly reduced at 20 and 180 μg GO/g dry weight sediment.Our results suggest that Au-NPs at 60 μg Au/g or GO-NPs at 20 and 180 μg GO/g were detected by T.tubifex as toxicants during short-term exposures.

River Water Quality Assessment in Selected Yangtze Tributaries: Background and Method Development

Water pollution is among the most severe environmental problems in China, particularly in the vicinity of residential and urban areas. In almost all Asian countries, river monitoring is predominantly based on the analysis of chemical data. However, biological data are a worthwhile addition for the determination of the long-term ecological status of rivers and are particularly well-suited in case of steep pollution and disturbance gradients. A tool for river water quality assessment using benthic invertebrates has been developed for selected tributaries of the middle reach of the Yangtze River. Site selection was supported by a preclassification considering physico-chemical and hydromorphological conditions. Following a stratified sampling design, 34 samples were taken in small and large streams in the subtropical mountainous area of western Hubei （湖北） （China） covering a pollution gradient, accompanied by an extensive field protocol on stream characteristics and （physico-） chemical water analyses. The proposed assessment system is computed as an average score per taxon. The challenge to further consider the additional impact from global change into the development of such tools is discussed.

Plasticity in the antipredator behavior of the orange-footed sea cucumber under shifting hydrodynamic forces

Marine invertebrates that move too slowly to evade unfavorable environmental change may instead exhibit phenotypic plasticity,allowing them to adjust to varying conditions.The orange-footed sea cucumber Cucumaria frondosa is a slow-moving suspension feeder that is preyed on by the purple sunstar Solaster endeca.The sea cucumber's antipredator behavior involves changing shape and detaching from the substratum,which might increase its probability of being displaced by water motion into an unsuitable environment.We hypothesized that sea cucumbers'antipredator responses would be diminished under stronger hydrodynamic forces,and that behavioral strategies would be flexible so that individuals could adjust to frequent changes in water flows.In a natural orange-footed sea cucumber habitat,individuals lived along a pronounced hydrodynamic gradient,allowing us to measure antipredator behavior under different water flow strengths.We placed purple sunstars in physical contact with sea cucumbers living at various points along the gradient to elicit antipredator responses.We then repeated this procedure in a laboratory mesocosm that generated weak and strong hydrodynamic forces similar to those observed at the field site.Subjects in the mesocosm experiment were tested in both wave conditions to determine if their antipredator behavior would change in response to sudden environmental change,as would be experienced under deteriorating sea conditions.Antipredator responses did not covary with hydrodynamic forces in the field.However,antipredator responses in the mesocosm experiment increased when individuals were transplanted from strong to weak forces and decreased when transplanted from weak to strong forces.Overall,our results indicate environmentally induced plasticity in the antipredator behavior of the orange-footed sea cucumber.