MEPS prepress abstract  -  DOI: https://doi.org/10.3354/meps12272

Initial occurrence, ontogenic distribution-shifts and advection of Nemopilema nomurai (Scyphozoa: Rhizostomeae) in Liaodong Bay, China in 2005-2015: Is the Liaodong Bay a possible source of bloom?

Jing Dong*, Bin Wang, Yan Duan, Won Duk Yoon, Aiyong Wang, Xiuze Liu, Yulong Li, Ming Sun, Yu Chai

*Email: 1024470248@qq.com

ABSTRACT: Large aggregations of Nemopilema nomurai have occurred in the northern East China Sea, Yellow Sea, and East Sea/Japan Sea since the end of 20th century, and Changjiang River mouth and its adjacent sea have been suspected as the source of jellyfish bloom. Bohai Sea, China located in the northwestern Yellow Sea has had similar blooms that have had a major impact on the local and regional fisheries, and as a consequence ecological studies have been initiated since 2005 to further understand the ecology and dynamics of this jellyfish. In this paper, we present results of N. nomurai’s spatiotemporal pattern in distribution and abundance in Liaodong Bay (LDB) and the southern waters of Liaodong peninsula. These waters exhibit decreasing temperature and increasing salinity with depth. Warm and less saline waters are found in the river mouths, and relatively colder and more saline waters in the central part of LDB. The first appearance of N. nomurai metaephyrae or juveniles in LDB occurs in the northern inner coastal areas every year, clearly indicating that LDB is a habitat of N. nomurai polyps. As the season progresses, N. nomurai become big and mature, this restricted distribution area expands to the whole LDB or advected to the southern Liaodong peninsula. This is interpreted as a horizontal advection that facilitates the N. nomurai’s population to complete its whole life cycle in the area.