The Evaluation Of Coastal Wetland Ecosystem In Sansha Bay

The wetlands are a kind of ecosystems which has a variety of unique features on the earth.It not only provides humans with large quantities of food，raw materials and water resources，but also plays an important role in many aspects，for example，maintaining ecological balance，keeping biological diversity and rare species resources，conserving water sources，storingfloodwater and preventing aridity，reducing pollution and regulating climates，replenishinggroundwater，controlling soil erosion and so on. Sansha Bay coastal wetland is a typicallandscape of the gulf. The surrounding landscape interacts with the sea view. At the same time，it has good ecological resources，such as the exotic islands，fertile estuaries，winding coastalbeach，beautiful mountains and forests，etc. Definitely，it has favorable conditions of developinggulf tourism. This study from the evaluation of the quality of the environment, ecologicalevaluation, comprehensive evaluation value rating of Sansha Bay coastal wetlands do a wholeecological evaluation results show that:1、Overall, the Sansha Bay water quality in good condition, the indicators are in line withthe second category of national water quality standards, but there is a growing trend of heavymetals like mercury, arsenic, ammonium, nitrate content. Intertidal and subtidal sediments ofenvironmental quality in general, the indicators are in line with the national standard II or III,were not excessive, but the trend of environmental contamination. September2005, thebiological quality status analysis showed that the heavy metals lead, cadmium, arsenic,petroleum hydrocarbons, DDT content in oysters than in the body of the mercury content of largeyellow croaker and white shrimp body, large yellow croaker,666, PCBs content is higher thanthe relatively low levels of these factors of several pollution indicators, oysters and shrimp, whiteshrimp and666in oyster and white shrimp total did not find, in addition to the large the yellowcroaker body mercury content in line with the national biological quality second-class standard,other indicators are in line with the national biological quality standards, the enrichment factor ofthe enrichment factor of the large yellow croaker was significantly higher than that of shrimp andoysters.2、Sansha Bay phytoplankton chlorophyll a mass concentration is low, modest interannualand seasonal changes, basic maintenance1.00mg/m3about the low overall level of primaryproductivity and seasonal changes in spring and summer, higher in autumn and winter thanis low.An increase in the amount of phytoplankton, while from2005to2006spring and autumn abnormally high, surpassed10×106/m3, diversity and evenness declined, the dominant speciesin the inter-annual presents replacement, Skeletonema costatum in early and recent dominant.The zooplankton biomass seasonal variation, the spring high autumn low, the overall downwardtrend, variety, species diversity, species diversity index is greater than3, and evenness of greaterthan0.8. Obvious trend of changes in the number of benthic organisms,2000, showing the trendof decrease after the first increase and a decrease in the number of species, the the two voyagesfindings below historical data, and in the proportion of species composition polychaetes. Littlechange in biomass characteristics intertidal habitat density, variety, and from2005to2006theannual spring and autumn survey reached139species and106kinds of high species diversityindex, maintained at about2.0. Ecologically sensitive areas including Sandu’ao the wetlandwaterfowl mangrove nature reserve, large yellow croaker Guanjingyang reproduction ofprotected areas, affected by human activities, area decreasing trend. Bay Spartina alternifloraflooded, a serious threat to the Gulf ecosystem. Sansha Bay wetlands have been included in thethe wetland List "China’s Action Plan for Wetland Protection", is one of the important wetlands,the existing provincial, municipal and county-level protection zone5, dispersed in differentlocations in the Bay, the ecological environment will be a certain protection.3、Sansha bay coastal wetlands ecosystem from the results of the assessment of the healthstatus of view, in a healthy state, and the state were lower than the weighted average of0.300,good natural coastal wetlands, coastal vegetation coverage is very low degree of landscapefragmentation, sediment unpolluted, bird species and more than the number of the variousindicators show that the the Sansha Bay coastal wetlands in general good health status, theecosystem is still in the range of self-regulation can bear, but a long time Chl a content The lowbenthic biodiversity decline than in the past, these should cause us to pay attention to. From apressure point of view, and the the Sansha Bay surrounding counties population density and percapita GDP close to the Fujian Province evaluate the level of per capita water emissions slightlylower than the average of Fujian Province. Sansha Bay history many times inning, but the harborarea, winding coastline, Bay Bay, ring Sansha Bay along the degree of industrialization in thelevel of underdevelopment, which coastal land use intensity shoreline Less developed. Greaterpressure on the sansha bay coastal wetlands ecosystem alien species Spartina cordgrass tidal flatsmadness spread as well as sewage emissions, which are caused by the degradation of the sanshabay coastal wetlands ecosystem. Internet spend the Spartina invasive native plants (such asmangroves) habitat, occupy the waterway, have a significant impact on farming and shipping, isfairly typical in Sansha Bay; the Sansha Bay sewage discharge in addition to land-basedemissions, excessive farming caused a large number of aquaculture wastewater discharged alsoan important reason, and farming a major source of pollution is the sea inorganic nitrogen and active phosphate. Together, the pressure index value in the range can withstand, if not solve theSpartina cordgrass and over-breeding problem Sansha Bay coastal wetland ecosystems pressurewill intensify in the future. From the response index, Sansha Bay coastal wetlands in response tothe strength of the general level. Sansha Bay set up a number of marine protected areas, theprotection of the harbor mangroves, wetlands, waterfowl and rare marine life, but thesurrounding counties is no sewage treatment facilities, industry, agriculture and sewage directlyinto the harbor, and sansha bay breeding density generated a large number of aquaculturewastewater also had an impact on the ecological environment protection management policiesand measures taken, can not completely relieve the subject of environmental pressures, if notincrease response efforts, it will cause the the coastal wetlands future ecological the deteriorationof the environment.4、Including integrated on the the Sansha Bay shoals ecological services value the direct usevalue and indirect use values, the sansha bay coastal wetlands total service value of about1.65billion yuan. Has great development prospects in sansha bay vast shoals ecological servicefunction hosted by the shoals, but can not be ignored in the development process, musteffectively strengthen the protection of the ecological environment, under the premise ofscientific planning and orderly development to achieve sustainable development.