There are two methods for creating fishing ground using artificial reefs. One is a pell-mell deployment and the other is an arranged deployment. The design of arranged deployment requires characteristics of fish interested in artificial reefs and the scale of artificial reef. However, it is still not clear for design method to arrange artificial reefs. Thus this study was carried out to develop the design method to optimally arrange reefs in terms of fluid dynamics. Consequently, in situ observation represented that the difference in artificial reefs arrangement affected the flow situations around artificial reefs.
The Asari （Manila）clam, Ruditapes philippinarum, is one of the most commercially important shellfish in the world. This species is native to coasts of the western Pacific. One population of this clam, on the Nakatsu tidal flats, Japan, has collapsed in recent decades. We relate extreme variations in tidal flat, sediment surface temperature to differences in survival of juvnile Asari clams recruiting into these flats. Most juveniles clams, settled into Nakatsu sediments in autumn rather than spring or early summer. Although there was little seasonal difference in water temperature in this period, spring to early summer sediment surface temperatures were considerly higher than those experienced in autumn. Low tidal sediment surface temperature from late June to mid August indicated over 40℃a critical temperature for survival of newly settled Asari clam. Extremes in sediment surface temperature during low tide in spring to early summer and autumn were caused by differences in day length, timing （daylight） occurrence of the low tide and seasonal variation in spring tidal height. When low tidal ground temperature fell bellow the critical level for survival of settling Asari clam in late September, survivorship was greater, ultimately contributing more individuals to the population than in any other season.
In this paper, the author described a definition, an operation and a shipʼs officer education on the training vessels of the fisheries university in Japan, and then illustrated the situation, the reason and the problem in the training vessel-building.
New training ship “Oshoro Maru V”of School of Fisheries Sciences, Hokkaido University was completed in July 28, 2014. The purposes of building were as follows; （1）development of human resources playing active role in the fisheries science, （2）utilization for interchange of personnel and international collaborative research with domestic and foreign universities and research organizations, and （3）contribution for the reconstruction of the fisheries resources and industry devastated by the 2011 Tohoku earthquake and tsunami. Based on fundamental concept as quiet floating campus with little ship motions, the ship was designed and constructed as an ideal fishery training ship.
For development of human resources that take on the responsibility of regional contribution and of marine industry of Kochi prefecture, the main aim of alternative ship construction of the fifth generation “Tosa-Kaien Maru”of Kochi marine high school is to educate and train third class ship officers. The alternative ship is a through double-layer decked cruiser, tuna long-liner fishing vessel of about 450ton.