Coastal Environmental Changes and Management in China in the Context of Global Changes and Human Activities

Coastal zone is the complex area with intense sea-land interaction. There are various types, complex environments and developed economy in coastal area of China. Under the influence of global change and human activities, the ecosystem of coastal zone is vulnerable and has sensitive response to environment changes. The environmental problems of sea-level rising have attached close attention by countries all over the world. As far as regions concerned, relative sea-level rising is more important than theoretical sea-level rising. The relative sea-level rising has resulted in series of environment disasters in coastal area of China, such as coastal erosion, seawater invasion, and floods in coastal lowlands, etc. The flux of sediments transported by rivers into sea is the main material source of marine pollution. The human activities are controlling factors of variations in river sediment loads. Under the influence of high strength development in the upstream region, the results are that the reduction of seagoing sediments in main rivers of China, and damage of coastal material balance. Land-based pollution is the main source of marine pollution. With rapid economic development in China s eastern coastal, pollutants flux into sea increase gradually. The results are that the environmental quality and seawater quality of marine have being deteriorated and pollution is serious increasingly. To meet the land demand of industrialization and urbanization, the sea reclamation has become an effective means to alleviate the contradiction between human and land in coastal area of China. This leads to large-scale reduction of coastal wetland area, and the heavy losses of ecological service value of coastal wetland. To face the environmental changes in coastal area of China and solve the contradiction among population, resources, environment, development, it is required to set up the system concept of man-land-sea relationship, so as to achieve sustainable development. The feasible measures include improving coastal management system, strengthening integrated basin management, attaching importance to construction of the coastal environment engineering, and raising the environmental monitoring and early warning level.

Sedimentary Characteristics and Response to Climate Change and Human Activities in Shilianghe Reservoir,Jiangsu Province

Reservoirs,as artificial lakes,suffer from silting inevitably since being constructed,the sediments from surrounding environment can provide a continuous record of environmental change.Shilianghe Reservoir,the largest artificial lake in Jiangsu Province,was constructed in 1959,and plays an important role in flood control,irrigation,water supply,and so on.Nevertheless,the silting situation of the reservoir is also quite serious.In this paper,the grain-size distribution of core from Shilianghe Reservoir and its response to environmental changes were studied.It is due to two driving factors:climate variability and human activities.Based on the analysis of the grain size distribution data,the sediments were mainly composed of clayey silt and silty clay with a clear tendency of upward fining.But a grain-size peak appeared at 86 cm,and the sand proportion was also very big,indicating that hydrodynamic force was stronger.There was a consistent trend of change between sediment record in Shilianghe Reservoir and historical precipitation in the basin.According to the dating mark of137 Cs,it can be determined primarily that the abnormal grain-size at 86 cm reflected possibly the rainstorm and flood event occurring in 1970.Human activities reduced the hydrodynamics of depositional environment.Hydraulic projects are direct human activities,and land use/cover changes are indirect human activities.It turned out that sediment yield and sediment load were more and more less,and sedimentation rate showed a decreasing trend.Furthermore,sediments tended to become smaller and had better sorting property.

MtsR, an Iron-Dependent Regulator in <i>Streptococcus iniae</i>

Streptococcus iniae (S. iniae) is a major pathogen that is capable of resulting severe economic loss to cultured fish. Steadily iron availability from micro-environment is an important virulence factor for pathogens, and S. iniae encodes the iron-transporter MtsABC to accomplish heme utilization, but very little was known about the mechanisms involved in regulating and maintaining iron balance in S. iniae. In this study, the role of a putative iron-dependent transcriptional regulator MtsR was investigated, and the results showed that MtsR regulated the expression of iron-transport mtsABC to control iron homeostasis in S. iniae.