The changes in marine environment and biological community in sea areas around an artificial upwelling structure during the summer

摘要

In order to examine the changes in a biological community in the South Sea of Korea that is caused by the installation of an artificial upwelling structure during the summer season when the forming of the stratification is the strongest, the researchers evaluate the water's temperature and nutrients, the standing crops and species diversity of phytoplankton and zooplankton, and the benthic organisms. The forming depth of Maximum Thermocline of Water Column (MTWC) is elevated after installing an artificial upwelling structure. Also, instead of showing a clear stratification where the concentration of nutrients increases as the depth of the sea increases, the distribution of nutrients after installing an artificial upwelling structure has changed, showing a lower degree of stratification by causing the mixing of the water mass. Compared to 2005, when the artificial upwelling structure was first introduced, the standing crop of phytoplankton and zooplankton has increased by 58.2 and 30.0 times in 2008, thus showing a tendency to increase as the size of the artificial upwelling structure becomes bigger. Also, the species diversity index of phytoplankton and zooplankton has increased and the size of the artificial upwelling structure has become greater. When the environment underwater around the artificial upwelling structure was examined in 2008, the underwater environment, arthropods such as Balanus albicostatus , mollusks such as Patinopecten yessoensis and Batillus cornutus , echinoderms such as Asterina pectinifera and Comanthus japonica , chordates such as Halocynthia roretzi , and fishes such as Sebastes inermis and Oplegnathus fasciatus were found, thus forming a benthic environment.