On the 88/89 regime shift in the marine ecosystems around Korea

Abstract

Past decades have seen many abrupt changes in the marine ecosystems adjacent toKorean Peninsula: Yellow Sea, East China Sea, and East Sea. The ecosystem changes inthese seas are expected to have a significant impact on the resource utilization in theregion. These changes are related with climate change as well as human activities thathave increased steadily in the region. It is difficult to tease out the compounding impactsof climate change and anthropogenic forcing.Of the changes, most prominent and common one in the three seas was the regimeshift around the end of 1980s. This shift seemed related to the warming and occurred inall the three seas with slight differences in the timing. Concurrent changes have occurredin climate factors, physical oceanographic variables, phytoplankton biomass, zooplanktonbiomass, and fish community structure. For the southern East Sea, we put forward ahypothesis on the linkage between the physical environments and lower trophic level inthis change. This hypothesis relates, among others, the Tsushima Warm Current as aproximate linking agent of large-scale climate variability and lower trophic ecosystem.However, at the moment, we do not have a hypothesis to offer that can explain theecosystem changes in the Yellow Sea and East China Sea, which occurred in a similartime frame. Further studies are needed to understand the mechanisms of the regionalscale ecization in theregion. These changes are related with climate change as well as human activities thathave increased steadily in the region. It is difficult to tease out the compounding impactsof climate change and anthropogenic forcing.Of the changes, most prominent and common one in the three seas was the regimeshift around the end of 1980s. This shift seemed related to the warming and occurred inall the three seas with slight differences in the timing. Concurrent changes have occurredin climate factors, physical oceanographic variables, phytoplankton biomass, zooplanktonbiomass, and fish community structure. For the southern East Sea, we put forward ahypothesis on the linkage between the physical environments and lower trophic level inthis change. This hypothesis relates, among others, the Tsushima Warm Current as aproximate linking agent of large-scale climate variability and lower trophic ecosystem.However, at the moment, we do not have a hypothesis to offer that can explain theecosystem changes in the Yellow Sea and East China Sea, which occurred in a similartime frame. Further studies are needed to understand the mechanisms of the regionalscale ec