HR: 0830h
AN: OS41C-0813    [PDF]
TI: Characteristics of Flow Field in Relation to transportation of Eggs and Larvae of Pelagic Fish in the East China Sea
AU: * Morinaga, K
EM: kenjim@affrc.go.jp
AF: Seikai national fisheries research institute, 1551-8 Taira, Nagasaki, 8512213 Japan
AB: Jack mackerel (Trachurus japonicus), one of the most familiar pelagic fishes in the East China Sea was been spawned between winter and spring, estimating from temporal and spatial distributions of fishing grounds near the Kyushu coast. Recently, from result of distributions of larvae collected during February to March, it was reported that main spawning grounds had been formed in the southern part of the East China Sea. These eggs and larvae are transported from spawning grounds by the Kuroshio, and a part of them branches northward at northwest of the Amami Oshima Island. This portion is considered to be distributed to the Sea of Japan by the origin of the Tsushima warm current. However, it is difficult to estimate the amount of eggs and larvae, since there is little information about the branched flow from northern edge of the Kuroshio to the Tsushima warm current during winter season. In this paper, in order to make it clear that how eggs and larvae are transported to the Pacific Ocean or the Sea of Japan from the southern East China Sea, the flow pattern in the East China Sea is to be described. Especially a flow that branches from the Kuroshio at northwest of the Amami Oshima Island is described in detail. Using many infrared imagery obtained by NOAA satellite, we detected both the frontal waves generated at the northern edge of the Kuroshio and the path of warm water branched from the frontal waves. These results revealed important information to measure the volume transport of the Tsushima warm current efficiently. Frontal waves are to be broken on the northern edge of the Kuroshio and became the origins of the Tsushima warm current. We carried out ADCP measurement in and around a breaking frontal wave, by using the quadrireciprocal method which requires four round trip surveys along a transect during a diurnal tidal period of 24 hours and 50 minutes in order to remove a tidal current. We were able to acquire a detailed information about a fine structure of the flow field. Furthermore, from records of the water thermometer equipped at four fixed points along west coast of Kyushu, it was also shown that warm water from the breaking frontal wave influenced to the coastal environment.
DE: 4243 Marginal and semienclosed seas
DE: 4512 Currents
DE: 4528 Fronts and jets
DE: 9320 Asia
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting