Kochi Prefecture Research Articles

Seasonal dynamics in fish distribution and abundance revealed by an acoustic survey in coastal waters of the Suzu Area, Kochi Prefecture, Japan

For Japan's fishery, it is essential to conduct sustainable and efficient fishery owing to the decline in fish catch as well as the fisher population. To obtain information that contributes to sustainable and efficient fishery, we researched appropriate set-net locations with regard to fish distribution, abundance, and environmental characteristics. We conducted surveys from 2017/5 to 2018/2 in the Suzu coastal area, Kochi Prefecture, where the only main industry is set-net fishery. We investigated the seasonal relationships between fish school characteristics, including distribution and size, and marine environmental conditions in the Suzu coastal area, using a quantitative echo sounder (KSE300 SONIC, 38 kHz) and other devices. We observed that every season showed similar trends in the horizontal structure; fish densities were higher on the coast side, and in some seasons, these were higher at approximately 2000 m offshore. In addition, fish densities were higher in seas at depths up to 30 m. Set-net fishery is conducted in Suzu District at 300 m from the shoreand at a depth of approximately 35 m. The point of installation of set-nets is based on fish school distribution. In our study, we determined the most appropriate set-net installation points. This study not only provides a scientific basis for point selection but could also enhance the existing fishery that is limited to an aging fisher population and catch instability.

高知県浦戸湾で得られたワタリガニ科のカニ類（十脚目：短尾下目）

高知県浦戸湾で得られたワタリガニ科のカニ類（十脚目：短尾下目）

高知県初記録のウスベニツバサカノコ（腹足網：アマオブネ科）

高知県初記録のウスベニツバサカノコ（腹足網：アマオブネ科）

高知県におけるクロウミウマの新産地と瀬戸湾からの追加記録（硬骨魚網：トゲウオ亜目）

高知県におけるクロウミウマの新産地と瀬戸湾からの追加記録（硬骨魚網：トゲウオ亜目）

Clinical profile and visual outcome of intraocular inflammation associated with cat-scratch disease in Japanese patients.

To evaluate intraocular inflammation in Japanese patients with cat-scratch disease (CSD). Retrospective clinical chart review. The cases of 15 consecutive patients (19 affected eyes) in Kochi Prefecture, Japan who were serologically positive for Bartonella henselae or Bartonella quintana infection in association with intraocular inflammation were reviewed. The clinical manifestations, ocular complications, and treatment modalities were recorded. The clinical charts and photographic records were also reviewed for evidence of optic disc lesions, macular star, foci of chorioretinitis, and other findings. Thirteen patients reported fever before or at the time of the initial presentation. Ten of 11 patients with decreased visual acuity manifested neuroretinitis, and the remaining patient showed retinochoroiditis with macular involvement. One patient with a visual field defect manifested branch retinal artery occlusion. Three patients without visual disturbance presented with fever of unknown cause. Discrete white retinal or retinochoroidal lesions were the most common findings (84% of eyes, 87% of patients), followed by retinal hemorrhage (63% of eyes, 80% of patients), optic disc lesions (63% of eyes, 73% of patients), serous retinal detachment (53% of eyes, 67% of patients), and macular star (47% of eyes, 60% of patients). White retinal or retinochoroidal foci were the most common ocular posterior segment manifestations of CSD in this patient population. A diagnosis of CSD should be suspected in patients with fever and chorioretinal white spots, and the absence of neuroretinitis or macular star does not exclude the possibility of intraocular inflammation in CSD.

Estimation of earthquake damage to urban environments using sparse modeling

For the establishment of precise disaster prevention measures in response to the Nankai megathrust earthquakes predicted to occur in the future, it is necessary to conduct numerous earthquake simulations and evaluate the vulnerability of the urban environment quantitatively. This vulnerability is evaluated on the basis of factors such as the extent of damage from earthquakes, as well as the attributes of residents, urban infrastructure, and systems in the environment. In this study, we propose a sparse modeling (SpM)-based technique for the evaluation of potential damage to urban environments due to Nankai megathrust earthquakes in Japan. As explanatory variables, any variables related to urban environments in Kochi Prefecture are considered. The results show that, unlike the so-called “complex disaster” events, the number of critical variables that characterize damage states when external disaster forces data (e.g. estimated seismic motion and tsunami height) and urban environment data are available is low, regardless of the magnitude of damage. In other words, urban system variables selected for damage states may be extracted as variables indicating vulnerability to earthquake damage. In addition, we evaluated the characteristics of different cities by visualizing the SpM results on a radar chart. The proposed technique is useful for gaining a deeper understanding of the influence of urban environment variables on earthquake damages. Furthermore, it is expected that measures for improving urban system resilience will be explored based on the proposed technique.

Multi-hazard earthquake-tsunami loss estimation of Kuroshio Town, Kochi Prefecture, Japan considering the Nankai-Tonankai megathrust rupture scenarios

The Nankai-Tonankai Trough is the primary source of major subduction earthquakes in western and central Japan, and the preparedness against future Nankai-Tonankai megathrust subduction events is of critical importance. This study develops a novel multi-hazard catastrophe model for the future Nankai-Tonankai megathrust subduction earthquake and tsunami based on a stochastic earthquake source modeling approach, and applies it to Kuroshio Town, Kochi Prefecture, Japan, that faces significant seismic-tsunami hazards due to the Nankai-Tonankai subduction earthquakes. The earthquake-tsunami catastrophe model incorporates the stochastic rupture sources, spatially correlated ground motion fields, tsunami inundation simulations, detailed building portfolio data, seismic and tsunami fragility models, and building damage cost estimation. It produces the multi-hazard and single-hazard loss distributions, accompanied by detailed earthquake rupture scenarios, shaking-tsunami hazard intensity distributions, and building damage distributions. The earthquake-tsunami loss estimation results for Kuroshio Town indicate that the tsunami loss tends to increase with the magnitude more significantly than the shaking loss and contributes more towards the increase in the multi-hazard total loss with the earthquake magnitude. Importanly, the new multi-hazard tool facilitates the identification of critical multi-hazard loss scenarios and leads to integrated hazard-risk maps that are particularly useful for disaster risk reduction and management purposes.

Food habits of raccoon dogs in Kochi Prefecture, Shikoku—stomach contents—

Food habits of raccoon dogs in Kochi Prefecture, Shikoku—stomach contents—

Proposal a road recovery method Considering the Number of Selection for Emergency Route and Restoration Date: A Case Study of Road Recovery Plan in Kochi Prefecture

Proposal a road recovery method Considering the Number of Selection for Emergency Route and Restoration Date: A Case Study of Road Recovery Plan in Kochi Prefecture

高知県沿岸から得られた四国初記録のミナミウシノシタ（ササウシノシタ科）と本種の成長に伴う形態・色彩変化

高知県沿岸から得られた四国初記録のミナミウシノシタ（ササウシノシタ科）と本種の成長に伴う形態・色彩変化

Washed up bivalves from the beach in Tosashimizu City, Kochi Prefecture

Washed up bivalves from the beach in Tosashimizu City, Kochi Prefecture

A Seafloor Survey Using Multiple Methodologies to Verify the Existence of a Village Submerged after a Historical Nankai Earthquake in Nomi Bay, Kochi Prefecture

A Seafloor Survey Using Multiple Methodologies to Verify the Existence of a Village Submerged after a Historical Nankai Earthquake in Nomi Bay, Kochi Prefecture

The Reality of Coastal Pole-and-Line Fishing of Bonito and Foreign Technical Interns: The Case of J-Maru of Kure, Nakatosa-cho, Kochi Prefecture

The Reality of Coastal Pole-and-Line Fishing of Bonito and Foreign Technical Interns: The Case of J-Maru of Kure, Nakatosa-cho, Kochi Prefecture

Paleoenvironmental changes and a tsunami deposit inferred from fossil diatom assemblages at Ohki lowland in Tosashimizu City, Kochi Prefecture, western Japan

Paleoenvironmental changes and a tsunami deposit inferred from fossil diatom assemblages at Ohki lowland in Tosashimizu City, Kochi Prefecture, western Japan

Acute stroke treatment in a local city ～an example in Kochi Prefecture～

Acute stroke treatment in a local city ～an example in Kochi Prefecture～

Plains Cupid confirmed in Susaki City, Kochi Prefecture

Plains Cupid confirmed in Susaki City, Kochi Prefecture

Challenges of Writing for Junior High School Students in Kochi Prefecture

Challenges of Writing for Junior High School Students in Kochi Prefecture

Records of Erthesina fullo (Thunberg,1783) (Heteroptera, Pentatomidae) from Kochi Prefecture and Tokushima Prefecture.

Records of Erthesina fullo (Thunberg,1783) (Heteroptera, Pentatomidae) from Kochi Prefecture and Tokushima Prefecture.

Four bird species newly recorded in Kochi Prefecture

Four bird species newly recorded in Kochi Prefecture

Washed up gastropods from the beach in Tosashimizu City, Kochi Prefecture

Washed up gastropods from the beach in Tosashimizu City, Kochi Prefecture