Standing stocks and production rates of phytoplankton and planktonic copepods were investigated at 15 stations in the Inland Sea of Japan during four cruises in October-November 1979, January, April and June 1980. The overall mean of phytOplankton biomass was relatively constant during the study period, ranging from 2.3 mg chl.αm^-3 in April to 3.6mg chl.αm^-3 in October-November. Primary production was low in January (mean: 90mg C m^-2 d^-1), but higher than 375mg C m^-2 d^-1 on the other occasions. Integrated annual primary production was 122g C m^-2 yr^-1. In terms of carbon weight, Paracalanus parvus was the most important copepod species. The variation of the mean copepod biomass (range: 7.6mg C m^-3 in April to 20.2mg C m^-3 in June) was smaller than that of copepod production, which was estimated by the Ikeda-Motoda's physiological method. Copepod producion was low in cold seasons (0.6 and 0.9mg C m^-3 d-' in January and April, respectively), and increased, following the elevation of primary production, to 4.9mg C m^-3 d^-1 in June. Annual copepod production was 33.7g C m^-2 yr^-1, of which herbivore (secondary) production was 26.4g C m^-2 yr (21.7% of primary production). The ratios of pelagic planktivorous fish catch and total fish catch to the primary production were 0.82 and 1.8%, respectively, indicating very highefficiency in exploiting fishery resources in the Inland Sea of Japan.

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We analyzed hydrographic data obtained monthly by the Iwate Prefectural Fisheries Laboratory during 1977-1981. Our attention was focussed on the classification of waters based on the Temperature-Salinity (T-S) scatter diagram analyses, and on the extraction of the “mean state” of their distribution for each season. The “water system” was defined as “all waters occupying some specific region on the T-S plane”, and the mean state for each season was expressed by the distribution of the “mode water systems” (i.e., the most commonly occuring water system).
Because of the coexistence of the Tsugaru Warm Current, the Oyashio and the Kuroshio, and their large seasonal variability, the sea waters had a wide variety of T-S combinations. The detailed T-S scatter diagram analyses allowed us to classify the waters into six water systems. A time-longitude diagram of water systems and the distribution of mode water systems are presented. The latter showed clear seasonal variations of the Tsugaru Warm Current and the Oyashio.
Though the water system analysis was successfully able to present the distribution of the various waters in the Sanriku Coastal Area and to clearly extract the mean state of sea conditions, it was found that the classification of water systems on the T-S plane was not complete in all cases for this area.

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This paper examines the influence of a Sargassum forest on the pH distribution in a small cove facing Wakasa Bay. The diurnal changes in spatial distribution of density and pH were observed in May 1977 during the season of luxuriant seaweed growth, and in August 1977 during the season of little growth. The observations were made at three-hour intervals for 24hr in May, and 9hr in August. During the period of strong density stratification, the observed pH distributions were divided into two types:(1) lower pH inshore and higher offshore in the upper layer in the evening and early morning, and (2) higher pH inshore and lower offshore in the daytime. During the period of weak stratification, a homogeneous pH distribution was observed. The pH distribution influenced by Sargassum forest during the season of luxuriant growth was different from that during the season of little growth. The process that brought these spatial distributions is discussed. From early dawn to forenoon during the season of luxuriant growth, the heavier water, produced inshore by cooling through nocturnal radiation, cascaded as a stable laminar flow under the lighter water remaining under canopies of the forest and detached floating seaweeds. Reaching the offshore lower layer, and co-acting with algal respiration, this cascade influenced pH distribution. Some dynamical parameters for the process of cascading are calculated and examined.

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Abyssal currents along the northern periphery of the Shikoku Basin south of Japan were measured by current meters moored off Cape Daio-zaki, Cape Shiono-misaki and Cape Ashizuri-misaki and on the eastern foot of the northernmost part of the Kyushu-Palau Ridge. Total length of observation off Cape Shiono-misaki was about five years including the periods of the Kuroshio large meander and no meander. Analyses of current data show:
1) Mean currents with a magnitude of 5-10cm sec-1 were observed during the whole observation period at all of current meters which were set 400m above the sea bottom that was deeper than 4, 500m. The mean current for each current meter was parallel to the local bottom contour arond each station and was toward a direction looking the Nankai Trough (a trough located along the northern end of the Shikoku Basin) to the left.
2) At each station located above the shelf toe off Cape Daio-zaki and off Cape Shiono-misaki and on the foot of the Kyushu-Palau Ridge, the mean current increases with depth (a bottomward intensification of the mean current), and the vertical extent of the mean current is estimated to be about 2, 000m above the sea bottom.
3) At a station located at 2, 600m depth on the continental slope off Cape Shiono-misaki, no bottom-ward intensification of currents was observed.
These results strongly suggest that a steady abyssal flow exists in the depths deeper than about 3, 000m along the northern and northwestern peripheries of the Shikoku Basin. Existence of the abyssal circulation system is also suggested, at least, in the north of the Shikoku Basin.

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Some aspects of the biology of the micronektonic fishes Cyclothone pallida and C. acclinidens are described on the basis of samples taken during a series of 20 cruises from December 1982 to November 1985 at a fixed station near the center of Sagami Bay, Central Japan. C. pallida is a regular component of the Cyclothone population in Sagami Bay, being found in more than 90% of the samples. On the other hand, C. acclinidens was encountered sporadically, being found in less than 25% of the samples. The depth range of C. pallida is estimated to be about 400-1, 000m. It spawns mainly during the spring and summer in Sagami Bay. C. pallida releases about 1, 000-3, 000 eggs and may spawn several times during its life span. On the average, it reaches 18.5mm standard length (SL) in one year, 24mm SL in two years and 29.5mm SL in three years during its subadult stage. Extrapolation of the growth curve suggests that males and females attain first sexual maturity in three to four years at 30-35mm and five to six years at 40-45 mm SL, respectively. Cyclothone pallida is concluded to have a regular life cycle in Sagami Bay. It remains uncertain whether or not C. acclinidens reproduces in this area.

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Copper toxicity in Chattonella antiqua (Raphidophyceae) was examined using an artificial seawater medium. The growth rate (μ) was found to be a unique function of cupric ion activity (acu) as follows:
μ=μmax/(1+K (acu) ²),
where μmax and K are 0.63 d^-1 and 2.4×10²⁰ mol^-2l², respectively. The value of acu at which μ is reduced to half the maximum is 10^-10.2M.
A comparison of our results with those for other phytoplankton species indicated C. antiqua to be rather sensitive to cupric ions. Furthermore, the growth of C. antiqua was strongly influenced at the calculated cupric ion activity of natural seawater in the Seto Inland Sea, assuming only inorganic copper complexation. Thus, organic chelation may be necessary before C. antiqua is capable of competing with other phytoplankton species.

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Adult females of Acartia omorii were allowed to feed on fecal pellets voided by its juveniles (copepodite stages I and II) in a mixture with the diatom Thalassiosira decipiens. The rate of filtering of pellets by adult females was 50.3±11.5ml indiv^-1 d^-1, being twice as high as the rate of filtering of T. decipiens.

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This is a review of the study on the oceanic environments relating to the marineliving resources carried out since 1947, during more than 35 years which are the period of the authors oceanographic research life for fisheries. Its content consists of describing the outlines of, (1) the oceanographic study of the Subarctic Region of the Northwestern Pacific as the salmon living waters, (2) the study on dilution processes of the effluent in the coastal waters in relation to marine pollution, (3) the oceanographic study on transportation and diffusion of fish eggs and larvae in relation to the recruitment of living resources and (4) the study on forecasting of the fisheries and oceanographic conditions, and a short note on direction of fisheries oceanography expected to be studied in the future.

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