Observational data along the regular sections in last 40 years (1965～2004) which have been performed by the Shizuoka Prefectural Fisheries Experiment Station were used toa nalyze long-term variabilities ofte mperature and salinity fields in the upper ocean layer of Suruga Bay and its surrounding area. Interannual variability of the temperature field showed (1) high amplitude in the subsurface layer ofar eas near the baym outha nd outside ofth e bay, byc haracterized as warmingi nt he lasth alfof 19 70s, and (2) the amplitude was eminent in the near-surface layer inside of the bay by warming since the last half of 1990s. The former change had high correlation with off-shore distance of the Kuroshio axis from Daiozak i, possibly because it is controlled by open oceanic condition. Similar interannual changew as also found int he salinity field ofth e subsurface layer in the same region, and thus the subsurface temperature and salinity became both higher when the Kuroshio had taken a large meander path. We detected a long-term salinity change which is dominant in the near-surface layer. This had a significant correlation with the lag of a half year with the precipitation change at Shizuoka, by suggesting the importance of freshwater flux through the sea surface or volume flux change from rivers.

The shelf topography plays an important role in the formation of the coastal branch flow of the Tsushima Warm Current. This shelf breaks a part of the branch flow around Toyama Bay. Although its path east of Toyama Bay has been inferred as the offshore baroclinic flow from temperature distributions, its flow pattern and seasonal variability around Toyama Bay have not been clarified. By using long-term GEK, ADCP and sea level data, we describe the seasonal change of surface current around the Bay. Sea level differences between Sado Is. (Ogi) and coastal stations (Wajima, Toyama, Kashiwazaki) reveal that there are two periods in which the eastward surface current velocity is enhanced in July and November. Based on this feature, we classify the annual cycle into five seasons in order to examine temporal change in spatial distributions of surface flow using GEK and ADCP data. The annual common flow pattern shows that there are two main paths, the one consisting of the eastward of shore flow (the boundary being 39°N latitude) and the other a coastal branch flow on the Japanese shelf joining near Sado Is (east of Noto Peninsula). This means that there is the northward flow west of Sado Is. throughout the year. On the other hand, the flow pattern around Toyama Bay has a prominent seasonal cycle, and our gridded current field with fine spatial resolution shows that there are actually two flow patterns. One is the inflow into Toyama Bay (the near-shore branch along the western bay coast) which is identified in April to September and weakens in September. The other is a flow across the bay mouth (the baroclinic flow from the north of Noto peninsula into Sado strait), which exists throughout the year and is clearly seen in autumn after the disappearance of Toyama Bay inflow.

Using an adhesion substrate (carrier of bacteria attached) and antagonistic bacteria of the Strain LMC9, this research produced a bioreactor and examined its repressing effect on the growth of the cold-water disease pathogen Flavobacterium psychrophilum on Ayu fish (Plecoglossus altivelis). Initially, a sterilized microscopic glass slide (2.6×7.6 cm) was adopted in order to check the interactions between the antagonistic bacteria LMC9 and F. psychrophilum on the adhesion substrate; that is, we followed fluctuations in the number of bacteria attached to it under different conditions. Consequently, when the glass slide was first immersed into antagonistic bacterium liquid, and successively immersed into the F. psychrophilum liquid (10⁹ CFU (colonyforming unit) ml^-1), the number of F. psychrophilum attached to the glass slide decreased with increasing concentrations of LMC9. The number of attached F. psychrophilum decreased significantly when the glass slide was immersed first in LMC 9 liquid of a concentration exceeding 10⁷ CFU ml^-1; the number of attached bacteria was several hundred times less than when immersed in 10⁶ CFU ml^-1 of LMC9 liquid.

Zeolite as an adhesion substrate was immersed in 10⁶ CFU ml^-1 of Strain LMC9 for 1h and then packed into a glass column to construct the bioreactor. When F. psychrophilum liquid (10⁴ CFU ml^-1) was introduced into this bioreactor at a rate of 1 L d^-1, F. psychrophilum could not be detected in the outflow liquid even on the 14^th day, using the agar plate culture method. But when F. psychrophilum at a concentration of 10⁶ CFU ml^-1 was introduced into the bioreactor, the above effect was not obtained; that is, F. psychrophilum in the outflow was detected on the agar medium by the 2^nd day of the experiment.

The outflow liquid from the bioreactor was examined with a PCR device to clarify whether even a very low concentration of F. psychrophilum could be detected when 10⁴ CFU ml^-1 of F. psychrophilum was introduced into the bioreactor. As a result, DNA of F. psychrophilum was detected on the chromatogram after PCR. This suggests that the growth ability of F. psychrophilum was repressed due to the antagonistic bacterial effect in the bioreactor, and consequently F. psychrophilum could not form colonies on an agar plate medium.

Most of this article deals with an oceanic anthology of “Tanka”, which is a traditional Japanese poem composed of five lines each having 5, 7, 5, 7 and 7 syllables, except for cases with extra or fewer syllables. This article is composed of three chapters: (1) an anthology composed and selected by the author, mainly related to fisheries oceanography; (2) an anthology of 54 poems related to the Kuroshio, all composed by various famous poets and classified into six categories; and (3) an essay entitled “Kuroshio and Japanese”. Since composing “Tanka” oneself and evaluating those composed byo thers are both difficult tasks, my selection of “Tanka” in this article might be arbitrary. As far as “Tanka” that are related to fisheries oceanography or to the Kuroshio, however, my unique experiences hopefully make a contribution in describing human and social aspects of Japanese oceanography.