Why did the copepod Calanus sinicus increase during the 1990s in the Yellow Sea?

Seasonal occurrence of Calanus sinicus in the northern South China Sea: A case study in Daya Bay

“…Calanus sinicus is a planktonic copepod species with a wide geographical distribution in the continental shelf waters of China, Japan and Korea (Chen, 1992;Kang et al, 2007;Uye, 2000). It is an ecologically important copepod species in the shelf ecosystems of the Northwest Pacific because its eggs, larvae and adults provide a wide size spectrum of food items for commercially important fish stocks in the near-shore spawning and nursing grounds (Zhu and Iverson, 1990).…”

“…It is an ecologically important copepod species in the shelf ecosystems of the Northwest Pacific because its eggs, larvae and adults provide a wide size spectrum of food items for commercially important fish stocks in the near-shore spawning and nursing grounds (Zhu and Iverson, 1990). As we face a changing environment, it is crucial to understand the climate-driven impacts on this key species because of its relevance to important fish stocks (Kang et al, 2007;Sun et al, 2002). Climate variability on interannual and inter-decadal scales has significantly affected the dynamics of copepods in the Northeast Pacific (Batchelder et al, 2013;Liu and Peterson, 2010;Liu et al, 2015).…”

Peaked abundance of Calanus sinicus earlier shifted in the Changjiang River (Yangtze River) Estuary: a comparable study between 1959, 2002 and 2005

“…The peaked abundance of C. sinicus may extend northward in consistent with the optimal temperature isotherms (17-18 • C). It was reported that average abundance of C. sinicus significantly increased in the Huanghai Sea compared with that in the 1980s (Kang et al, 2007). Strong biogeographic shifts in copepod assemblages were found with a northward extension of warm-water species due to the temperature increase in sea surface water, accompanied by a decrease in number of colder-water species (Hays et al, 2005;Beaugrand et al, 2002).…”

“…4), which may be responsible for its disappearance. The shifts in peaked abundance of zooplankton were affected by some kinds of environmental factors besides breeding cycle (Mackas et al, 2007), such as water temperature (Beaugrand et al, 2002), food supply and predation pressure (Kang et al, 2007;Pu et al, 2004). In this study, except for the temperature increase, the red tides mainly caused by temperature and nutrients (Shen et al, 2010;Huang et al, 2002) may accelerate the decrease of peaked abundance of C. sinicus in June of 2005.…”

“…The distribution of C. sinicus showed strong seasonal character and its abundance peaked in spring but attenuated in summer Uye, 2000). It has been shown that the distribution pattern of C. sinicus in the Huanghai Sea in spring was controlled by temperature, rather than food (Kang et al, 2007;Kang, 2004). The high amount of C. sinicus in the Huanghai Sea Cold Water Mass (HSCWM) was suggested to be an avoidance of the lethal SST in summer (Li et al, 2004;Pu et al, 2004;Wang et al, 2003).…”