DETECTING DECADAL CHANGES IN MARINE ENVIRONMENTAL CHARACTERISTICS AND FISHERY RESOURCES IN KOREAN WATERS

participantChanges in temperature and salinity were analyzed using serial station data of NFRDI (National Fisheries Research and Development Institute) from 1962 to 2007, by dividing Korean waters into eight areas, which are two in the Japan/East Sea, three in the Yellow Sea, and three in the East China Sea. RSI (regime shift indices) were calculated for the eight areas to examine patterns of the changes among the areas. All the eight areas showed decadal patterns of the changes in the years of 1976-77, 1988-89 and 1998-99, which are widely known as the years of climatic regime shifts (CRS) in the North Pacific. The changes in the index for 1988-89 and 1998-99 were stronger than that for 1976-77. The changing pattern for 1976-77 was only shown in the Japan/East Sea at E1 and E2 stations, and the RSI was weak in 1976-77 at S3 which is connected with E2. Although changes in RSI were commonly detected in 2006-07 in the whole Korean waters, the magnitude was not statistically significant. The 1976-77 CRS was manifested by a replacement in biomass and catch of major exploited fisheries resources, such as Pacific saury, sardine and filefish in the Japan/East Sea. In addition, fishery production in the waters showed decadal fluctuation trends with an increase in 1976, a decrease in 1986, and an increase again since late 1990s. In 1960s and 1990s common squid was the most dominant, but in 70s and 80s it was replaced by walleye pollock. Other CRS events also changed the structure and function of the marine ecosystem, and the biomass and production of fisheries resources in Korean waters