**4. Acknowledgment**

This study was funded by the State 863 High-Technology R&D Project of China (2003AA603510 and 2004AA603310), the Knowledge Innovation Program of the Institute of Oceanology, Chinese Academy of Sciences (Y02507101Q), The National Natural Science Foundation of China (NSFC) (41076100 an31072212) and the earmarked fund for Modern Agro-industry Technology Research System (nycytx-50).
