To explore impact on marine habitats caused by coastal pollution, predictive models of the Indo-Pacific humpback dolphin (Sousa chinensis) distribution were generated using the Maxent modelling approach, based on dolphin occurrence data in Sanniang Bay and its adjacent waters in Guangxi Province during 2006-2007, the independent oceanographic parameters derived from Google Earth Digital Elevation Model (DEM) and Landsat images, and the water environmental data from the marine investigation in 2012. Results indicated that the distance to the major river mouths was the strongest predictors, and water nutrition and persistent pollutants were the important factors for the dolphin distribution in both wet and dry seasons. Based on the results, habitat selection strategies of the dolphin were discussed: the dolphin tended to select estuaries with abundant prey and avoid highly polluted areas, which could be useful in designing Marine Protected Areas (MPAs) and formulating management strategies.

Based on related study on land use and methods of ecosystem service value assessment, using GIS technology, this paper analyzed the land use changes of Hongsipu irrigated area 1996, 2000, 2006 and 2010 and calculated ecosystem service value, in order to study how the ecosystem service value changes with the land use. Results showed that the changes of land use in Hongsipu irrigated area were significant from 1996 to 2010. The main land use types are grassland, cropland and sandy wasteland. In 1996 the main type was grassland while in 2010 it’s changed to cropland. During 1996 to 2010, grassland area decreased and cropland area increased most significantly, followed by the increase of construction land and woodland area, while water area changed slightly. Total ecosystem service value of the study area increased from about 249.56 million yuan in 1996 to about 266.64 million yuan in 2010, which showed an increasing tendency. It’s the increase of cropland and woodland area that caused the increase of total ecosystem service value. And also the ecosystem service value of cropland, woodland and water accounts for 84.59% of the total ecosystem service value. The distribution of unit area ecosystem service value is also closely related to land use changes and directly reflects the process of land use change during the irrigated area construction and development, indicating that the land use changes of Hongsipu irrigated area had a positive effect on total ecosystem service value increase.