夏季大规模死亡一直是困扰贝类养殖产业健康发展的世界性难题。引发贝类夏季病害爆发的因素种类繁多且相互关联、错综复杂，而生态免疫学从机体能量代谢平衡和免疫的能量代价角度为研究贝类病害发生机制提供了新思路。繁殖期能量的分配及免疫防御能力的变化是解析贝类夏季病害发生的核心，环境病原微生物及宿主共生微生物群落变化是揭示贝类病害发生的关键。本研究拟运用生态免疫学、分子生态学、免疫学、细胞和分子生物学等方法手段，调查环境因素变化及其对夏季长牡蛎死亡的影响，探究夏季长牡蛎能量代谢、分配特征及其调节机制，免疫应答水平的变化及其调控特征，解析环境病原微生物及共生微生物群落变化及其致病机理，以期揭示长牡蛎疾病爆发的原因，阐释长牡蛎体内外微生物与宿主的相互作用，为长牡蛎病害的免疫防治及预警预报体系的构建提供理论基础。

The large-scale summer mortality of bivalve is a worldwide problem, which threatens the healthy and sustainable development of the aquaculture industry. There are various factors contributing to the oyster summer mortality, and they are closely intricately interrelated. The emerging ecological immunology provides a new insight into the mechanism of the bivalve disease with the idea of trade-off and immune cost. The changes of energy metabolism and allocation as well as immunity during the reproductive period are the prerequisites of the occurrence of bivalve disease. The alternations of pathogenic microorganism in the environment and host symbiotic microbial community are the key determinants of the outbreak of summer mortality. The techniques including ecological immunology, molecular ecology, immunology, cell biology and molecular biology are employed in the present study to (1) investigate the changes of environmental factors and their effects on the summer mortality of oysters, (2) explore the changes of energy metabolism and allocation, the change of immune response level, and their regulation mechanisms of oyster during reproductive period, (3) analyze the change of symbiotic and environmental microbial community and the pathogenic mechanism with the objectives to reveal the causes and mechanism of oyster summer mortality. The results may provide a theoretical basis for the prevention and control of the oyster diseases and the construction of the early warning and prediction system.