Regional Report for PICES Region: 19 - Marine Ecosystems of the North Pacific Ocean 2009–2016

In particular, a long-term decreasing trend of the upwelling index during the summer seasons of 1948-2018 was reported for the Korean coast and considered to be caused by the changes in the summer monsoon. [...] ⚫ Giant Jellyfishes invasion which occurred in the southern part of Region 19 in the middle of the 2000s and caused serious harm to the fisheries and tourism has not been observed during the 2010s. [...] The slowdown of the long-term deepening in deep water boundaries (between Central Water and Deep Water and between Deep Water and Bottom Water) and bottom water dissolved oxygen is supported by structural changes observed in the deep water masses and results of the 1-dimensional model and allows the formation of a three-layered deep structure expected to remain until at least 2040 (Fig. [...] The spatial trend pattern is rather homogeneous in the entire sea; however, the trends are stronger in the southern area, up to 7 mm/yr in the south-western part and up to 6 mm/yr in the south- eastern part (Fig. [...] The fluorescent intensity of the humic-like component was negatively correlated with salinity in the surface water of the sea and the continental shelves (Kim and Kim, 2015).