International Conference on Coastal Zones
Osaka, Japan
You-Shao Wang
State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology,China
Title: Long-term changes in Daya Bay ecosystems of South China Sea in response to human effects
Biography
Biography: You-Shao Wang
Abstract
As a venue of rapid industry, aquaculture development, urban expansion and population growth, Daya Bay is a natural laboratory to study the influences of human activities on coastal ecosystems. Satellite observations suggested that two nuclear power plants operated here have direct impacts on the local environment at the southwest part of Daya Bay, which takes up to ~3% (2002) and ~7% (2003) of the entire bay. Field observations over 1998 to 2007 suggested that human activities here had substantially altered the nutrient balance and driven this bay into a P limiting environment. In the past decade, phytoplankton biodiversity in this bay decreased by ~25% accompanied with significant change in community structure. Ecosystem degrade in Daya Bay was further evidenced by the observed trend of elevating petroleum hydrocarbon level. Principle Component Analysis (PCA) suggested that the long-term variations of water quality and phytoplankton biomass in Daya Bay can be grouped into three distinct clusters: Cluster A (1998 and 2004-2006) characterized by high concentrations of NH4-N and TIN and high TIN/PO4-P ratios, Cluster B (1999, 2002 and 2003) characterized by high concentrations of NO2-N, NO3-N, SiO3-Si, and chlorophyll a and high SiO3-Si/PO4-P ratios, and Cluster C (2000, 2001 and 2007) characterized by high PO4-P and phytoplankton concentrations. Marine reserve within Daya Bay was suggested and discussed based on these findings.