The Yellow Sea and East China Sea have undergone drastic 꼧 changes in the pastdecades as witnessed by species shifts, increasing outbreaks of HABs, andjellyfish blooms. More recently, macroalgal blooms appeared in the westerncoastal areas of the Yellow Sea and East China Sea (Liu et al. 2009). These andother changes indicate the ecosystem structure is rapidly shifting.꼧There is clear evidence of ongoing eutrophication in the Yellow Sea from therecord of organic deposition in sediments, increases in biomass and abundanceof the benthos during the past decade, and the appearance of an hypoxic area.꼧Warming of the ocean surface waters has occurred since the mid- to late 1980s,with a parallel increasing trend in mesozooplankton abundance. The mechanismof this linkage and a possible interaction with eutrophication is unclear.꼧Changjiang River discharge has been reduced with an accompanying impact onecosystem productivity and structure in the vicinity of the river mouth. Animpact on a larger scale on the shelf area is not yet evident.꼧In the Yellow Sea, nitrogen:phosphorus and nitrogen:silicon ratios have beenincreasing basin-wide for the past three decades.꼧The most prominent pressures to the ecosystem in the past decades wereoverfishing, eutrophication and disturbances in the freshwater budget.꼧A recent survey indicates that the volume of the Yellow Sea Bottom Cold Wateris reduced.꼧A complicated network of pressures, anthropogenic as well as natural, is atwork in these ecosystems with an anticipation of even more changes in nearfuture. These changes are expected to have a significant impact on the resourceutilization of the Yellow Sea and East China Sea.