Institute for Marine Resources and Environment Geological Survey of Japan AIST, Tsukuba, Ibaraki, JAPAN

a-usui@aist.go.jp

　

The compilation and simple statistics of the distribution patterns and compositional variations of ferromanganese crusts, nodules and hydrothermal massive sulfides demonstrated the characteristic distribution patterns in good correlation to geological and topographic settings of the northwestern Pacific Ocean around the Japanese Islands. Sample description, metal concentrations, and sea-bed photos have been archived for marine minerals collected at about 800 locations out of more than 15,000 search sampling points, and shall be soon open as one of homepages of the Research Information Database section (RIO-DB) of the National Institute of Advanced Industrial Science and Technology (AIST).

　

Hydrogenetic ferromanganese nodules and crusts commonly occur in the areas of erosion or non-deposition over the Cretaceous seamounts and plateaus on the Pacific plate, and less frequently on seamounts of the remnant arcs of the Paleogene to Neogene ages. The Pacific seamount crusts are most enriched in Co, and the latter is less so, while both show moderate Ni enrichment. The deposits are by contrast rare in the active volcanic arcs or backarc basins, where volcanic and tectonic activities prevent growth of hydrogenetic deposits. A very slight early-diagenetic influence is observed in some basin nodules. On the other hand, modern hydrothermal Mn deposits of specifically pure composition are widely distributed on active submarine volcanoes and backarc rifis. The contents of metals are within negligible levels except for Mg, Ba, K, and Li. Polymetallic massive sulfide deposits (PMS) have been discovered widely over the two major active volcanic island-arcs in association with modern hydrothermal venting.

　

　

¹Natl. Inst. of Advanced Industrial Science and Technology Tsukuba, JAPAN

tetsuo-yamazaki@aist.go.jp

　

²Metal Mining Agency of Japan Tokyo, JAPAN

　

Manganese nodule, seafloor polymetallic sulfide, and cobalt-rich manganese crust have received special attention as future mineral resources for Co, Ni, Cu, Mn, Au, Ag, Zn, Pb, and Pt. Their survey, R&D of the mining and metallurgical processing technologies, and study of mining impacts on the environment have been continued with private companies and nations these 40 years. The activities in the first stage in 1960s and 1970s were initiated with some international consortium organized by private companies, but their interests were gone away with less market demands ofthe metals in 1980s. The second half in 1980s and 1990s, the activities in this field were led with nations from viewpoint of national security.

　

Private companies, however, are coming back in development of deep-sea mineral resources these years. In order to understand the current situation, economic potential of the deep-sea mineral resources are re-evaluated. Though the re-evaluation is underway now, the preliminary results for manganese nodule and cobalt-rich manganese crust are introduced.

　

　

Faculty of Agriculture, Ehime University Tarumi, Matsuyama, JAPAN

kharada@agri.ehime-u.ac.jp

　

To examine the extent of genetic variation within and among populations of Kandelia candel, AFLP analysis was applied to 10 populations in Nansei Shoto. A total of 382 fragments were detected using three selective primer pairs. The proportion of the polymorphic loci and the average heterozygosity (H) for each population were ranged from 22.5 to 43.5% and 0.060 to 0.145, respectively. The means are 31.7% and 0.084, respectively. The nucleotide diversity (π) was estimated by the method of Innan et al. (1997) and ranged from 0.0060 to 0.0150 and averaged 0.0082. The nucleotide diversity shown here is about 66% of the values shown in Fagus crenata and 44% of Quercus mongolica, both are broad leaf deciduous trees in Japan; however, the fixation index (Fst) is shown to be 0.170 showing extensive differentiation among the populations. Amami-oshima population showed the largest values in both H and π UPGMA tree showed no association between the geographic distance and the genetic distance among the populations. Remarkable difference was shown between the west and the east coast populations in Okinawa Jima. NJ tree constructed on the fragment data of individual samples suggests that the population of Iriomote Jima has served as a source of genetrc vanatron.

　

　

College of Science, University of the Ryukyus Nishihara, Okinawa, JAPAN

mkunishi@sci.u-ryukyu.ac.jp

　

Since the early 1960s the red algal genus Laurencia has been subject of many chemical investigations throughout the world. Some 40 species of the genus has so far been explored, yielding more than 300 characteristic metabolites. However, the tropical species L. luzonensis has remained untapped until recently when we reported an unusual diterpene, 3-bromobarekoxide, possessing a seven-membered ring fused to trans-decalin and several new bromosesquiterpenes.

　

Our continuing research on the alga has yielded additional new sesquiterpenes. A fresh sample of the alga was extracted with ethanol. After concentration the resulting aqueous suspension was extracted with ethyl acetate to give an oil. The oil was separated by repeated chromatography on silica gel and purified by high performance liquid chromatography to yield five new sesquiterpenes. In this presentation we report the isolation and structure elucidation of the new compounds.

　

Key words: sesquiterpene, structure, elucidation, brominated compound

　

　

Department of Biology¹, Food and Nutritional Sciences Programme², and Food Science Laboratory³ , The Chinese University of Hong Kong Shatin, HKSAR, CHlNA

joyce_mwc@yahoo.com

　

Bromophenols are responsible for the sea-like and brine-like flavor in seafood. Aquacultured animals lack such flavor due to the presence of low concentrations of bromophenols. Most seaweed contains bromoperoxidases to synthesize the natural bromophenols. Therefore, the objective of this study is to evaluate a seaweed-based feed on the enhancement of the bromophenol content in an aquacutured fish.

　

A fish feed was prepared with a seaweed (Sargassum siliquastrum) containing relatively high bromophenol contents (1730 ng/g dry weight), and was used to feed the cultured silver seabream (Sparus sarba). The enhancement effect on the fish was evaluated by monitoring the changes in bromophenol contents in the fish flesh at different times and by evaluating the organoleptic character of the fish by human sensory panelists.

　

Results showed that the seaweed-containing fish feed could significantly increase the bromophenol contents in the flesh of the seabream after they were fed with the special feed for a period of eight weeks (p<0.05). The cooked fish flesh prepared from fish fed with seaweed-containing feed was significantly different in organoleptic character from that of the control one (p<0.05).

　

Bromophenol-containing seaweed feed could successfully increase the bromophenol contents, and provide desirable organoleptic character in the cultured fish. This study suggested that the seaweed-containing fish feed could be useful in enhancing the bromophenol contents in aquacultured animals, and hence their sensory properties