ORIGIN OF THE GIANT JELLYFISH IN QINGDAO OFFSHORE IN SUMMER
青岛外海夏季水母路径溯源研究

In the summer of 2011, massive giant jellyfish was observed in Qingdao offshore. These jellyfish, including Nemopilema nomurai,Cyanea nozakii and Aurelia aurita, were remote origin because their larvae were not found in Qingdao offshore in the past winter and spring. We conducted a series of backward Lagrangian particle-tracking experiments driven by the Princeton Ocean Model (POM) hydrodynamical results to identify possible source regions of the observed giant jellyfish. Passive particles representing the jellyfishwere released in surface layer and at some other depths atdifferent times in summer. The trajectories of the particles depended on both the depth and the date of release. Backward tracking from the summer to spring, the released particles insurface layer were mainly found in Haizhou Bay, Jiangsu coast area, and the region adjacent to Changjiang Estuary, and those released at 10m depth and the bottom were all found to the north of 35°N. These places may be the source regions of the observed massive giant jellyfish. This conclusion was also supported by the consistence of the jellyfish species in these areas and Qingdao offshore.