Inland Sea Region Research Articles

Spatial characteristics of seawater pCO<sub>2</sub> in the Seto Inland Sea and adjacent region

Spatial characteristics of seawater pCO<sub>2</sub> in the Seto Inland Sea and adjacent region

Evaluation of straightforward and rapid multi-element analyses of stream sediments for geochemical mapping in the remote islands of Japan — Seto Inland Sea region —

The straightforward and rapid determination of 53 elements in stream sediments using ICP-AES (inductively coupled plasma atomic emission spectrometry), ICP-MS (inductively coupled plasma mass spectrometry), and AAS (atomic absorption spectrometry) were evaluated for the geochemical mapping of isolated islands. Samples of 0.1 g were decomposed with HF, HNO3, and HClO4 at 125–145°C for 3 h to improve the determination of elements, including refractory minerals. The concentrations of rare earth elements (REEs), Nb, and Ta increased by 5–15% on average, and those of Zr and Hf increased by 30% on average. For arsenic determination, 0.1 g samples were digested using a mixed acid solution with an oxidizing reagent (KMnO4) at 120°C for 20 min. Decomposition without using the oxidizing reagent and/or extended decomposition times has been shown to cause a decrease in As concentrations in geochemical reference materials. However, similar As concentrations in stream sediment samples were obtained irrespective of KMnO4 addition and decomposition time. AAS was used to Hg measurement after thermal decomposition of about 50 mg samples without pre-treatment. The estimated concentrations of 53 elements in geochemical reference materials measured using ICP-AES, ICP-MS and AAS were agreement with the recommended values. Thus, it is concluded that the precision and accuracy of the rapid and straightforward analysis for geochemical mapping were satisfactory.

The possibility of deeper or shallower extent of the source area of Nankai Trough earthquakes based on the 1707 Hoei tsunami heights along the Pacific and Seto Inland Sea coasts, southwest Japan

To validate the abundance of scenarios of large earthquakes in the Nankai Trough, we examined the effects of both lateral and vertical expansions of the source areas on maximum tsunami heights along the Pacific coast and Seto Inland Sea. The recently proposed Nankai Trough earthquake scenario (Mw = 9) has a maximum slip of 20 m near the trough axis. However, the predicted tsunami heights exceeded those obtained from historical records of damage caused by the 1707 Hoei tsunami event at Tosa Bay and along the Pacific coastlines near the Kii Channel, owing to the large slip on the up-dip extension of fault segments off Shikoku Island. Such discrepancy indicates that for segments off Shikoku Island, the slip near the trough axis was unremarkable, even for the 1707 Hoei earthquake event, which is considered one of the larger historical Nankai Trough earthquake events. For segments east of the Kii Peninsula, the large slip on the up-dip end might be ineffective. While the proposed Mw9-class scenario also includes large slip of several meters on the down-dip side (down to about 35-km depth), coseismic crustal subsidence reached further landward than is usual for Nankai Trough earthquakes. For the Seto Inland Sea region, this resulted in maximum subsidence of about 1 m, and such crustal subsidence effectively increased the height of the tsunamis. Furthermore, simulated tsunami heights, corrected for crustal subsidence, were in good agreement with those obtained from historical records of the damage caused in the Seto Inland Sea region.

Phylogeography of Quercus phillyraeoides (Fagaceae) in Japan as revealed by chloroplast DNA variation

In order to elucidate the phylogeographical relationships and to find the past colonization routes of evergreen oak (Quercus phillyraeoides), we collected samples from 19 populations from the central to western part of Japan and examined chloroplast DNA sequence variation. We analyzed the genetic variation for four non-coding and one coding region and examined a total of 3,665 bp. Total nucleotide diversity (π) was 0.00017 ± 0.00001, and the scaled mutation rate (θw) was 0.00021 ± 0.00011. These values were relatively smaller than those formerly reported for Japanese deciduous oak species (Q. mongolica var. crispula). A total of five haplotypes, two of which included two subtypes (A1, A2, B, C, D1, D2, E), were identified, with types A1 and D2 the most frequent. A large degree of genetic differentiation had occurred across the populations (GST = 0.833 for haplotype data and FST = 0.858 for sequence data). The data suggested several possible refugia populations on the Pacific Ocean coast and the East China Sea coast, nearly identical to those previously suggested for the lucidophyllus forest refugia. We could not find any evidence showing that any part of the Seto Inland Sea populations could be possible refugia. Largest genetic differentiation across the populations in the Seto Inland Sea region suggests that these areas have been recently colonized following the last glacial maximum from the refugia in the Pacific coast or in southern Kyushu.

Network and Information Exchange Among Salt-pan Communities in the Seto Inland Sea Region(Article on the Symposium Topic,<Special Issue>the 37th Symposium on Marine Transport and Network in Japan)

Network and Information Exchange Among Salt-pan Communities in the Seto Inland Sea Region(Article on the Symposium Topic,<Special Issue>the 37th Symposium on Marine Transport and Network in Japan)

Molecular detection of pestiviruses in aborted foetuses from provinces in northern Turkey

All pestiviruses are important veterinary pathogens causing economic losses in cattle, sheep and pigs. Besides the important economical losses, pestiviruses may compromise the normal immune response to other pathogens and increase the severity of other infections in sheep. In this study, aborted foetuses (cattle and sheep) in either coastal or inland Black Sea region of Turkey were surveyed for the presence of RNA from pestiviruses (bovine viral diarrhoea virus (BVDV), border disease virus (BDV)). The presence of BVDV RNA was found in 6 of 21 aborted calves (28.57%), although BDV RNA was detected in 14 of 21 aborted lambs (66.66%) by reverse transcriptase polymerase chain reaction. This study also investigates the distribution of viral RNA within the brain, liver and lung of aborted foetuses. The viral RNA positivity rates for the organs varied and were as follows: brain 40.47% and liver and lung 38.09%. The results revealed that pestiviruses are important abort pathogen in the provinces of northern Turkey.

Molecular Detection of Crimean‐Congo Haemorrhagic Fever Virus (CCHFV) but not West Nile Virus (WNV) in Hard Ticks from Provinces in Northern Turkey

In this study, the hard ticks collected from a variety of mammalian species (cattle, sheep, goat, buffalo) and a turtle in either coastal or inland Black Sea region of Turkey were surveyed for the presence of RNA from Crimean-Congo haemorrhagic fever virus (CCHFV) and West Nile virus (WNV). No WNV genomic RNA was detected in any tick sample. However, CCHFV RNA was found in 29 of 421 tick pools (6.88%). Positivity rates for the provinces varied and were as follows: Samsun 4.38%; Ordu 4.34%; Giresun 6.32%; Sinop 14.63%; Amasya 5.55%; Tokat 3.38% and Sivas 4.83%. Crimean-Congo haemorrhagic fever virus genomic RNA was detected in seven of eleven tick species tested. These results suggest that these hard ticks may act as a reservoir for CCHFV in northern Turkey, but probably have no role in WNV transmission.

An antigenic investigation of Crimean-Congo hemorrhagic fever virus (CCHFV) in hard ticks from provinces in northern Turkey

Crimean-Congo hemorrhagic fever virus threatens human health. Exposure of the infected tick is a strong risk factor for human disease. In this study, the hard ticks collected from a variety of mammalian species (cattle, sheep, goat, and buffalo) and a turtle in either coastal or inland Black Sea region of Turkey were surveyed for the presence of antigen from Crimean-Congo hemorrhagic fever virus (CCHFV). CCHFV antigen was found in 46 of 421 tick pools (10.92%). Positivity rates for the provinces varied and were as follows: Samsun 33.87%, Ordu 4.34%, Giresun 8.86%, Sinop 6.09%, Amasya 7.40%, Tokat 5.08%, and Sivas 8.06%. CCHFV antigen was detected in seven of 11 tick species tested. These results suggest that these hard ticks may act as a reservoir for CCHFV in northern Turkey.

Tidal Simulation around Japanese Coastal Region with a Global Ocean Tide Model

This study examines the sensitivity of tidal simulation to the model-domain size, and validates the accuracy of tidal simulation with broad model domain as the storm surge simulation. The tidal simulation models which adopt the driving force given by the global ocean tide model are developed. The models cover the Seto Inland Sea and coastal region of Kyushu-Shikoku with three different model-domain sizes. The size of the broadest domain is just as the storm surge simulation. Validation with the tide-gauge data shows that the accuracy is high in the narrower domain cases, however, in the broadest domain case the calculational error of tide becomes large in Bungo Channel and eastern coastal region of Kyushu.

Predators, Protectors, and Purveyors: Pirates and Commerce in Late Medieval Japan

OVER the course of late medieval Japan (ca. 1333–1590), some leaders of seafaring bands who appear in historical sources as “pirates” (kaizoku ) gained widespread acceptance as important figures in the political and economic structure of the time.1 Japan in this period was subject to two large historical processes: decentralization in the political realm and commercialization in the economic. Contests over the post of shogun and the imperial succession, internecine inheritance feuds, and the rise of local elites resulted in a decentralized political order in which no one could fully enforce a claim to be the ultimate arbiter of sanctioned violence. In such an environment, often only brute force sufficed to resolve disputes.2 At the same time, the economy was growing increasingly complex. Estate (shoen ) networks linking proprietors and producers competed with, intersected with, and sometimes evolved into cash-based regional, transarchipelagic, and overseas commercial networks.3 In much of Japan, especially the Seto Inland Sea (Setonaikai ) region, commercialization occurred most dynamically in the littoral. A range of traditional and new authorities established ports, toll barriers, lodges, and other infrastructure

Information Distribution of Tokugawa Shogunate Envoys' Return Itinerary from Nagasaki to Edo : Analysis of Information .Distribution Process from the area around Nagasaki to the Seto Inland Sea Region

Information Distribution of Tokugawa Shogunate Envoys' Return Itinerary from Nagasaki to Edo : Analysis of Information .Distribution Process from the area around Nagasaki to the Seto Inland Sea Region

Production of juvenile marine finfish for stock enhancement in Japan

Utilizing the potential and untapped productivity of the sea through the development of stock enhancement technology has a long history in Japan. In 1997, of the 88 species of seed produced in Japan by 284 facilities, 73 species were released. The total numbers of finfish seeds produced and released were 97 million from 36 species, and 71 million from 30 species, respectively. Over 10 million seed were produced for each of three finfish species: Japanese flounder ( Paralichthys olivaceus) and red sea bream ( Pagrus major), which have been developed throughout Japan, and black sea bream ( Acanthopagrus schlegeli), which has been developed only in the Seto Inland Sea region and the Japan Sea region. Steady progress made by stock enhancement programs, based on the release of hatchery-raised juveniles, has highlighted the importance of physiological, morphological, and ecological characteristics of the hatchery-raised juveniles in the effectiveness of the release operations. Fish health (or physiological wellness) and fish quality (or ecological robustness, described in terms of behavior and feeding activity) determine the ability of hatchery-raised juveniles to adapt to natural conditions in released environments. The releasing time, which is dependent upon the spawning time, is another important factor affecting the recovery rate of released hatchery-raised seed. Technological development of broodstock management is in induced spawning techniques, including manipulating temperature and photoperiod. Technological development of seed production in Japan has shifted its focus from quantity to quality, since health and adaptability of hatchery-raised seed are the most important factors determining the recovery rate. As a result, the focus of development of stock enhancement technology for the Japanese flounder and red sea bream is on raising the quality of health and the adaptability of the seeds.

地球温暖化防止施策検討のための都道府県単位の二酸化炭素排出構造の試算

In this study, CO2 emission sources are categorized into industrial sector, business and household, transportation, waste treatment, and energy supply sector, and their emission of CO2 are estimated respectively. Based on the calculation, carbon dioxide emission pattern in Japan is viewed.This study indicates that regions with large amount of CO2 emission are located in the Tokyo-Osaka-Fukuoka corridor. Especially carbon dioxide emission is large in prefectures which are in suburban of metropolitan areas and the Seto Inland Sea Region. This fact is due to intensified activities of heavy industries such as theiron and steel industry, chemical industry, and machinery industry which are located in these areas. Industrial structure have an influence on CO2 emission pattern in prefectural zones. It is clear that the classification with primary, secondary, and tertiary industries is incomplete for estimation and that each secondary industries have different emission per yield.

瀬戸内海沿岸域における環境特性マップ作成の試み

In recent years, more interest has been paid to making environmental indices, through a synthesis of the various environmental data, for the purpose of understanding the environmental status of a region.In this study, we have chosen the Seto Inland Sea region of Japan as our study area. We have set six environmental indices and analyzed the value of each index by using twenty-one environmental data factors. The region was divided into 207 municipal areas, which serve as the units for estimation, providing a detailed view of the study area. Using these environmental indices, a cluster analysis was performed on the entire region. These values were further classified into seven regions exhibiting similar environmental characteristics. The results were then used to create a map detailing the environmental characteristics of the region.

A Markov approach for describing post‐fire succession of vegetation

AbstractVegetation dynamics in the coastal area of the Seto Inland Sea region in Japan, where wild fires occur frequently, were described using a stationary Markov model. In this region, vegetation types of Miscanthus‐Pleioblastus grassland, Lespedeza‐Mallotus scrub, Pinus‐Rhododendron forest and Crassocephalum‐Erechtites community have been identified, and these show cyclic succession under the influence of fires.The model uses parameters determining fire frequency and rate of successional change to analyze the effect of variation in these parameters on the areal ratio of each vegetation type at equilibrium and on the time taken for one vegetation type to succeed another (elapsed successional time). The effect of fire frequency differs between hypothetical habitats with high and low productivity. A policy for vegetation management in areas of high and low productivity is proposed. The advantages and limitations of applying Markov models to studies of vegetation succession are also discussed.

Sacral Kingship and Confederacy in Early Izumo

A SERIES of startling archaeological discoveries in old Izumo province during the 1980s has changed our vision of how that region developed from Yayoi through early imperial times. Of particular interest is the way in which this new evidence is expanding our understanding of political organization and rulership in early Japan. Japan's early history as it is known in the West is largely Yamato-centered. That is hardly surprising, for the Yamato area saw the emergence of an early political hegemony that subsequently became the center of Japan's first unified state. In recent years, however, widespread construction work and popular support for archaeology have brought the buried past to light in many other regions of the country. The new data fills critical gaps in the written record even as it challenges parts of that record. Although historians in Japan as elsewhere have traditionally preferred written sources as the basis for their research, they have recently taken a great interest in the work of archaeologists and ethnologists, seeking a broader array of data and methods by which to trace the evolution of society, polity, and culture. A fuller understanding of historical processes and a firmer sense of chronology have resulted. In the twenty years since Professor John Hall provided English-language readers with a first look at this kind of work for the old Inland Sea region of Kibi in his Government and Local Power in Japan, 500 to 1700, a great deal has been learned about other regions as well. My attention was drawn to this progress when I took part in the Early History Seminar (Nihon Kodaishi Sama Semina) in Matsue City during July 1987. The seminar is a yearly event that brings together early historians, archaeologists, and ethnologists. In 1987 discussion focused on recent discoveries in former Izumo province, part of present-day Shimane prefecture.

A NEW METHOD FOR IDENTIFICATION OF INTER‐AND INTRA‐SPECIES OF THE RED TIDE ALGAE CHATTONELLA ANTIQUA AND CHATTONELLA MARINA (RAPHIDOPHYCEAE) BY MEANS OF MONOCLONAL ANTIBODIES1

ABSTRACTFour monoclonal antibodies AT‐83, AT‐86, MR‐18 and MR‐21 were obtained from culture supernatants of hybridomas which had been established by cell fusion between myeloma and spleen cells of mice immunized with the raphidophycean algae Chattonella antiqua (H) O NIES‐83 and 86 and Chattonella marina (S) H et C NIES‐118 and 121, respectively. Antibody AT‐86 was reactive with all ten strains of Chattonella antiqua tested but not with those of Chattonella marina. On the other hand, MR‐18 was reactive with those of Chattonella marina but not with those of Chattonella antiqua. Species can thus be identified using these two antibodies. Antibody MR‐21 was reactive with some of the strains of Chattonella antiqua and all six strains of Chattonella antiqua and all six strains of Chattonella marina. AT‐83 was reactive with some strains of Chattonella antiqua By the selective reactivities of these four monoclonal antibodies, strains of the two species could be separated into two groups. AT‐83 could distinguish between Chattonella marina isolated from Kagoshima prefecture (reactive) and the Seto Inland Sea region (non‐reactive). Reactivities of MR‐21 suggested that at least two groups of Chattonella antiqua caused red tides in Harima‐Nada during 1977 and 1978. Monoclonal antibodies appear to be useful for the identification of inter‐species and grouping of intra‐species of these organisms.

Wet deposition of sulfate in the Inland Sea region of Japan

Precipitation chemistry data derived from a sampling network operated in the Inland Sea model region (June 1984–May 1985) are used as a basis for discussing the wet deposition of sulfate on a regional scale in Japan. Horizontal distribution, seasonal variation, relationship between wet deposition and precipitation amount, sulfate/nitrate ratio, and transport of sulfate from the ocean are discussed. Temporal trends in concentrations of atmospheric sulfur compounds and sulfate wet deposition in the model region are also covered.

Natural regions of Japan

In order to subdivide the natural regions of Japan, first, the regional subdivisions or distributions of geology, landforms, soils, climates, hydrology, flora, forests and vegetations are shown separately. The characteristics of the subdivided regions or zones are described briefly to illustrate the distribution of every element in Japan. Secondly, a tentative division of natural regions of Japan is given in reference to the subdivisions or distributions mentioned in the first part. The numbers of the natural regions of Japan tentatively proposed in this paper are 7 in the 1. order, 20 in the 2. order and 58 in the 3. order. The average area of the 3. order regions in Kyushu, Shikoku, Honshu and Hokkaido is about 8,100 km2, which implies a meso-scale dimension. The names of the regions in the 2. order are: I1) Nansei Islands, I2) Daitojima, II1) Ogasawara Islands and others, II2) Minamitorishima (Marcus Is.), III1) Pacific coast (Nankai), III2) Mountain area of SW Japan, III3) NW Kyushu, III4) Inland Sea region, III5) Pacific side of Central Japan, IV1) Izu Islands, IV2) Kanto-tosan, IV3) Pacific side of NE of Honshu, V1) San'in district, V2) NW of Central Japan, VI1) NE of Central Japan and S of N Honshu, VI2) Japan Sea side of N Honshu, VI3) SW Hokkaido, VII1) Pacific side of Hokkaido, VII2) E of Hokkaido, and VII3) W of Hokkaido.

Prospect for the Future Environmental Change of the Inland Sea Region in Japan

Along the shores of the Inland Sea in Western Japan, many new factories have been constructed here and urbanization have remarkably expanded during the 1960's. As a results the region is facing air and water pollution and also urban sprawl is aggravated. We regret to say we had scarcely any scholars who studies to forecast the present condition. This paper is the first report of study on the future environmental changes of the Inland Sea region which deals with land and sea areas. We recognized that the following two points seem to the basic subjects to investigate : 1) to discuss the balance of water supply and demand on account of the Mediterranean sea climate and lack of big rivers, 2) consider to the quality of sea water inflow of home usage water, industrial and agricultural effluents. And we made efforts to approach the objects through systematic analysis on the items-size of population and industrial output in the future, possibility of developing water resource and discharge of pollutant water into the sea.The results of this research are summarized as follows : 1) During the period from 1965 to 1985, the region will come to have 10.6 million inhabitants, its concentration into the small coastal lands will be accelerated, and the industrial output will increase eight times, which is much indebted to the growth the heavy-chemical industries. The estimated demand for fresh water will amount to 75 million tons daily, incidentally 52 million tons are now needed every day. As it is difficult to meet the demand especially in the central part of the region, that part will surely become a serious water shortage area. 2) Total volume of the BOD, COD, SS and oil pollutant will amount to 1.4 times during the period from 1969 to 1985, even under the government restriction on the discharge level which is 50 percent severer. The industrial and agricultural effluents occupied the greater part of burden, and the COD pollutant will increase remarkably.The point which author especially emphasizes is that we have make efforts to alter the industrial structure from resource-consuming industries to value added industries, and to promote to use the recycled water for home usage. But the study on the diffusion of polluted water in the sea is the subject for a future study.