High nutrients in the coastal area after heavy rain observed in the central Seto Inland Sea in July 2012

Temporary enhancement of the nutrient concentrations in the coastal area was observed after heavy rain in the central Seto Inland Sea in July 2012. After passage of a stationary front accompanied by heavy rain, the river outflow was enhanced, and low salinity and high nutrient concentrations were detected near the mouths of rivers. The offshore salinity and nutrients increased and decreased, respectively, which suggested that a snapshot event, such as heavy rain, could influence the short-term variation of the coastal marine environmental conditions, such as the salinity and nutrient distributions.     

Trajectories of drift bottles released in the Tsushima Strait

Kyungsang-Namdo Fisheries Experimental Station released 620 drift bottles in the west strait of the Tsushima Strait from 1932 to 1939. Among them 183 were recovered. Fukuoka Prefectural Fisheries Experimental Station also released 1930 bottles in the east strait between 1954 and 1969. Recovered bottles were 442.The bottles drifted to the south in winter owing to a northwesterly wind, and drifted to the northeast in spring and summer with the Tsushima warm current. Bottles released at the west strait drifted to the north along the east shore of Korea, went around the Ullung Island, and then to the northeast. Drift bottles released at the east strait drifted to the north along the shore of Japan and washed ashore on the coast.