The wastes and overflows of deep-sea water (DSW) have been released from land-based systems into coastal waters in Toyama Bay. To predict the effects of the enriched and cold water on Gelidium beds, relative growth rates (RGR) of cut-off Gelidium elegans Kützing branches were examined by culturing for ten days in an incubator (NEDO Bio Cube) using running DSW. In the culture to find optimal turnover rates of DSW, RGR were higher at 5-10 times/day than 1-3 times/day. In the following cultures to find optimal sea water temperature (10, 15, 20, 25 and 30°C) and light intensity (20, 60, 100 and 200μE/m²/sec), higher values of RGR were obtained at 20-25°C and at 60-100μE/m²/sec, respectively. At 20-25°C and at 200μE/m²/sec, one or more branches regenerated from each fracture more frequently. Then effects of dilution of nutrients were tested by culturing in DSW mixed with surface-sea water (SSW) at five rates (percentage of DSW/SSW; 100, 75, 50, 25, 0%). As the result, RGR elevated in waters of higher DSW rates at a combined optimal condition (5times/day, 20°C and 60μE/m²/sec). Using these data, growth of G. elegans in DSW-released areas in Toyama Bay were predicted as the function of seawater temperature and nitrogen concentration on the assumption of nitrogen limitation in coastal waters. When DSW (3°C) is released into coastal waters (SSW temperatures: 27°C in summer, 10°C in winter), growth of G. elegans will be enhanced only in summer. When released after warmed by 15°C, growth will be enhanced in both seasons. However, in higher DSW rates, an epiphytic diatom, Arachnoidiscus ornatus may increase in number and damage Gelidium beds as suggested in the present study.

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The continuous analysis of the nitrate concentration will make clear causes of the changes of nutritive salts in deep seawater. Nitrate concentrations in deep seawater pumped up in Toyama Bay were analyzed over the period of two years from January 2003 to December 2004, at hourly intervals by using ion chromatography. Deep seawater were pumped up at two different locations, at Namerikawa City (NaC) and Nyuzen Town (NyT), from the depth of 321 m and 384 m, respectively. The concentrations were usually 23 to 24 μmolL^-1 at NaC and 24 to 25 μmol L^-1 at NyT. However, some changes often occurred and continued for several hours to several days. Their changing ranges were greater at NaC (8.8 to 25.0μmol L^-1) than at NyT (17.6 to 25.4μmol L^-1). The decrease of nitrate concentration was relatedto the temperature rise. The changes usually occurred first at NaC and then at NyT, several hours later. The distribution of nitrate concentrations and temperatures from surface to 700 m depth were analyzed. Those data suggested that a seawater mass with a lower nitrate concentration and a higher temperature often might be moving in the bay, going down for 150 m, reached to the inlet of intake pipe of deep seawater. The reason that the range of nitrate concentration change at NyT is smaller than the one at NaC, could be due to the fact that the inlet of intake pipe at the former is deeper by about 60 m than the one at the later.

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In Toyama Bay, catch of sandfish, Arctoscopus japonicus, has decreased dramatically. The authors have reared brood stock of the deep-sea (cold water) species using pumped deep seawater assuming the release of mass juveniles. As reported previously, we have already succeeded in collecting eggs from reared 1-year-old brood stock in tank. In the present study, the following trials were made to obtain mass eggs; continuing culture of the used brood stock (continuously-reared group, N=200) in 4kl tank and mass production of 1-yearold brood stock (mass production group, N=3, 250) in 33kl tank. These brood stock cultures resulted in production of 189, 400 eggs in prolonged spawning periods (2 to 3 months). Most of these eggs were kept in surface-sea water to control water temperature (elevating from 4 to 12°C via 7 and 10°C) during egg incubation. As the result, we could concentrate hatching at the expected timing (last week of December) to start the seedling production from the larvae earlier than the usual trial by two months. Furthermore, by culturing the larvae in landbased tank and subsequently in sea-based net cages, we could obtain larger seedlings by 30 mm in total length in May. Some problems, including prolonged spawning periods, low spawning rates (=number of females spawned per stocked) (20-43%), low eyed-egg rates (47-73%), low hatching rate (27%) and high initial dropout (>98% of dead juvenile in two weeks) during seed production were pointed out and discussed in relation to the culture conditions.

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The objective of this study was to evaluate the effect of Suruga Bay deep-sea water on the growth and maturation of gametophytes of Eisenia arborea Areschoug. The gametophytes were cultured under the laboratory conditions, e.g. in surface water (SW), Suruga Bay deepsea water (DSW), and Provasoli's enriched seawater (PES) without iron. Average growth rate of somatic cells in male and female gametophytes were 139, 93 % in SW, 200, 175 % in 397 m DSW, 245, 247% in 687 m DSW, and 266, 213 % in PES without iron, respectively. After each culture medium was replaced by one containing iron, the gametophytes were continuously cultured for another 21 days. At the end of culture, the maturity rates of female gametophytes in SW, 397 m DSW, 687 m DSW and PES were 30, 50, 80 and 100 %, respectively. These observations suggest that Suruga Bay deep-sea water is suitable for the growth and maturation of the gametophytes.

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In the deep seawater utilization in a recent aquaculture field, only the deep seawater is often used as breeding water without mixing it with the surface seawater to maintain the cleanness of the deep seawater. For these cases, because the water temperature of the deep seawater is low, the technology that heats the deep seawater up to a suitable temperature to breed the living thing of the fishery is demanded.
In this development, the deep seawater temperature management system that efficiently adjusted the temperature by heat recovery from the heat source water such as the breeding drain or the surface seawater was developed. The measurement of the operating situation of this system was executed, and the performance of the equipment and the effect of energy conservation were clarified.
As a result, it was clarified to achieve a big effect of energy conservation compared with the system that did not recover heat, though it differed depending on conditions of the temperature and the flow rate of the heat source water. Moreover, based on the experiment results, an annual heat recovery rate of the development system was presumed, with a parameter of the flow rate ratio of the heat source water and deep seawater.

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Sandaracopimarinol, one of the diterpenes, has been isolated for the first time along with β-sitosterol from deep seawater pumped up from 687 m in the Suruga Bay. Sandaracopimarinol has been found in the Japanese cedar (“Sugi” Cryptomeria japonica), which is widely planted in the eastern Japan. We speculate that the above organic compounds have been discharged by rivers to the seawater from terrestrial environment.

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