著者
渡辺 勝敏 一柳 英隆 阿部 司 岩田 明久
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.61, no.2, pp.69-83, 2014-11-05 (Released:2016-12-25)
参考文献数
27
被引用文献数
1

The population of the botiid Parabotia curtus in the Katsura River, Lake BiwaYodo River system, Kameoka, Kyoto Prefecture, Japan, the only one recorded in the Kinki region since the year 2000, was subjected to a population viability analysis (PVA) based on demographic data between 2006 and 2013 (8 years). Count-based and age-structured models with several conditions for density-dependence, carrying capacity, migration rate, and bias in population estimation (48 settings in total) were used for calculating the quasi-extinction probability within 50 years (extinction threshold <10 individuals), using computer simulations. The estimated population for the 8 year period fluctuated from 200 to 2,300 individuals (average ca. 935, with a coefficient of variation of 66%). PVA demonstrated a significant extinction risk for this population (23–82% extinction in 45 of 48 settings). Although further population monitoring is necessary for a more precise evaluation, we conclude that this population faces a real extinction risk. Sensitivity analysis suggested several requirements for effectively enhancing population viability, i.e., restraining large biotic and abiotic environmental perturbations to avoid extreme depression of the recruitment of young, enhancing winter survival, and promoting upstream migration into the spawning site.
著者
阿部 司
出版者
応用生態工学会
雑誌
応用生態工学 (ISSN:13443755)
巻号頁・発行日
vol.15, no.2, pp.243-248, 2012 (Released:2013-04-24)
参考文献数
28
被引用文献数
2 2

Japanese kissing loach Parabotia curta (Cypriniformes, Botiidae) is one of the most endangered freshwater fishes in Japan. This species inhabits in a narrow region of western Honshu Island. The loach inhabits rivers and irrigation channels with gravel substrates hiding in crevices or holes, and spawns for a few days in the early rainy season at temporarily submerged, flooded grounds, which were originally very common lowland environments in monsoon Asia. However, recent artificial environmental changes, especially river improvements and farm land consolidation, have destroyed such environments and resulted in many local population extinction. Volunteers and Japanese/local governments are performing restoration and maintenance of artificial floodplains for the spawning as well as surveillance of poaching, but this loach is still critically endangered with some serious problems. In the agricultural area which has many restrictions, conservation techniques cannot be fully put to practical use. Although the technique of the ecology and civil engineering is effective for the restoration of floodplain environment and improvement of habitat, the sociological approach is crucial to utilize the technique in the local community.
著者
阿部 司
出版者
応用生態工学会
雑誌
応用生態工学 (ISSN:13443755)
巻号頁・発行日
vol.15, no.2, pp.243-248, 2012
被引用文献数
2

Japanese kissing loach <i>Parabotia curta</i> (Cypriniformes, Botiidae) is one of the most endangered freshwater fishes in Japan. This species inhabits in a narrow region of western Honshu Island. The loach inhabits rivers and irrigation channels with gravel substrates hiding in crevices or holes, and spawns for a few days in the early rainy season at temporarily submerged, flooded grounds, which were originally very common lowland environments in monsoon Asia. However, recent artificial environmental changes, especially river improvements and farm land consolidation, have destroyed such environments and resulted in many local population extinction. Volunteers and Japanese/local governments are performing restoration and maintenance of artificial floodplains for the spawning as well as surveillance of poaching, but this loach is still critically endangered with some serious problems. In the agricultural area which has many restrictions, conservation techniques cannot be fully put to practical use. Although the technique of the ecology and civil engineering is effective for the restoration of floodplain environment and improvement of habitat, the sociological approach is crucial to utilize the technique in the local community.
著者
毎熊 輝記 阿部 司 斎藤 徳美 小林 直太 中島 直吉 中村 操 野越 三雄 MAIGUMA Teruki ABE Mamoru SAITOH Tokumi KOBAYASHI Naota NAKAJIMA Naoyoshi NAKAMURA Misao NOGOSHI Mitsuo
出版者
社団法人物理探査学会
雑誌
物理探査 (ISSN:09127984)
巻号頁・発行日
vol.40, no.5, pp.p338-356, 1987-10
被引用文献数
1

The 1983 Japan Sea Earthquake(M=7.7)caused heavy damage associated with remarkable liquefaction to many houses and the ground soils at certain areas(2kmx6km)in the Noshiro City region, Akita Pref. The geomechanical character of the ground there has been investigated through use of shear wave velocities from in-situ measurements, results of grain-size analyses, geoteclmical in formation from many drill holes and data for ground water depths. Almost all of the sites investigated in many places are underlain by loosely-packed sandy soils of fine-to medium-grained sediments(0.3 mm~0.5 mm), with low shear wave velocities less than 120m/s and small values of uniformity coefficients between 1.6 and 2.3. Seismicmicrozonation maps showing areas where local soil conditions would be favorable for liquefaction have been compiled for assessing future earthquake hazards in certain areas. In the Noshiro City areas investigated, all sites with shear wave velocities less than about 120m/s and with ground water depths less than 2 meters would be much likely to liquefy except for sites underlain mainly by silty and clayey soils. Sites with shear velocities greater than 150m/s would not have susceptibility to liquefaction.