Researcher Profile and Settings

Affiliation

• Field Science Center for Northern Biosphere　Aquatic Research Station

Job Title

• Associate Professor

J-Global ID

• 201301025580993714

Research Interests

• 計量魚探機   藻場   水産音響   沿岸生態系   

Research Areas

• Life sciences / Aquaculture
• Environmental science/Agricultural science / Environmental dynamics

Research Activities

Published Papers

• Spatial and economic quantification of provisioning service by eelgrass beds in Lake Notoro, Hokkaido, Japan

  Keizo Ito, Shiori Sonoki, Kenji Minami, Susumu Chiba, Hokuto Shirakawa, Toshifumi Kawajiri, Yanhui Zhu, Kazushi Miyashita

  Scientific Reports 14 (1) 2024/02/14 

  Abstract Eelgrass beds provide a habitat for many high-value fishery resources, and provisioning services, one of the ecosystem services, need to be quantified. However, few examples have been evaluated spatially. We determined the distribution of eelgrass beds in Lake Notoro, a marine lagoon in Hokkaido, Japan, and quantified the provisioning services by the eelgrass beds in relation to Pandalus latirostris, a fishery resource. Acoustic measurement surveys of the eelgrass beds and catch surveys of the shrimp were conducted in July and August 2015. The relationship between catch per unit effort (CPUE) of shrimp and the distribution of eelgrass beds was shown. The estimated distribution area of eelgrass beds was 7.07 km². Shrimp was frequently caught at water depths of 3–5 m, approximately 200 m from the edge of the eelgrass beds. The expected catch of shrimp in the fishing area of Lake Notoro in 2015 was 25.37 tons and US$ 463.6 thousand. Eelgrass beds were found to affect the fisheries production not only on the inside but also at the edge and outside. The entire coastal space should be evaluated, while considering the effect of the distribution of eelgrass beds, to quantify the provisioning services.
• Practical target strength of free-swimming chub mackerel Scomber japonicus

  Yanhui Zhu, Keizo Ito, Kosuke Mizutani, Kenji Minami, Hokuto Shirakawa, Yohei Kawauchi, Yuka Iwahara, Kimiharu Nahata, Nobuhiko Sato, Kyosuke Seki, Mitsuki Kuroda, Kazushi Miyashita

  Fisheries Science 0919-9268 2023/12/01
• Bayesian estimation of the abundance of northern fur seals Callorhinus ursinus in the wintering and feeding ground off Sanriku on the Pacific coast of northern Japan

  Yu Kanaji, Hiroto Murase, Hiroshi Nagashima, Kenji Minami, Ryuichi Matsukura, Takashi Setou, Hiroko Sasaki, Shiroh Yonezaki

  Fisheries Science 89 (3) 289 - 299 0919-9268 2023/02/11 [Refereed]
  
• Target Strength Measurements of Free-Swimming Sandeel Species, Ammodytes spp., in a Large Indoor Experimental Aquarium

  Yanhui Zhu, Kosuke Mizutani, Kenji Minami, Hokuto Shirakawa, Yohei Kawauchi, Huamei Shao, Makoto Tomiyasu, Yuka Iwahara, Tsutomu Tamura, Masahiro Ogawa, Kai Tatsuyama, Kazushi Miyashita

  Journal of Marine Science and Engineering 10 (7) 966 - 966 2022/07/14 [Refereed]
   

  The sandeel species (Ammodytes spp.) occupy a critical ecological position in connecting lower trophic levels to higher ones. However, they are strongly affected by the marine environment and their catch rates are trending downward. In this study, the target strength (TS) of sandeel species was measured in free-swimming specimens using a split-beam quantitative echo sounder with 38 and 120 kHz frequencies in a physically controlled environment. Parameters a and b used in the estimated TSmean–fork length (FL: 13.5–21.5 cm) equation were 53.7 and −124.3 dB at 38 kHz, and 71.3 and −153.2 dB at 120 kHz, respectively. The TS of the sandeel species were not proportional to the square of the FL but increased relatively rapidly with increasing body size. In addition, the mean and standard deviation of the swimming angle for the sandeel species from the acoustic data at 120 kHz were −2.2° and 7.7°, respectively, and most were in the −30° to 30°, range. Furthermore, TS was stronger at 38 kHz than at 120 kHz for all FL classes. The use of such frequency characteristics could facilitate the discrimination of fish species in the field and the sustainable assessment of sandeel species stocks.
• Estimating target strength of young chum salmon (Oncorhynchus keta)

  Kenji Minami, Hokuto Shirakawa, Yohei Kawauchi, Huamei Shao, Makoto Tomiyasu, Yuka Iwahara, Yuichi Tsuda, Hideo Takahara, Yanhui Zhu, Kazushi Miyashita

  Canadian Journal of Fisheries and Aquatic Sciences 79 (2) 195 - 199 0706-652X 2022/02 [Refereed]
   

  Although chum salmon (Oncorhynchus keta) is an important fishery resource in Japan, acoustic methods cannot be applied to biomass estimation because the target strength (TS) is unknown. This study clarified the TS for each fork length (FL: 5.5–33.5 cm) of young chum salmon inhabiting the Japanese coastal area to the Bering Sea by measuring free-swimming fish. The size dependences of the TS values were TS_mean = 20 log₁₀ FL – 68.0, for both 38 and 120 kHz. This facilitated the estimation of biomass of young salmon using acoustic methods.
• 福島県さくら湖における計量魚群探知機を用いた藍藻類の音響計測の試み

  中森陸, 南憲吏, 白川北斗, 朱妍卉, 沖津二朗, 大杉奉功, 東信行, 金相曄, 谷田一三, 黒田充樹, 長岡祥平, 佐藤信彦, 宮下和士

  Laguna(汽水域研究) 29 87 - 98 2022 [Refereed]
  
• 長期間の連続観測データからみた宍道湖の水質の変化特性

  金相曄, 瀬戸浩二, 南憲吏, 林昌平, 清家泰

  Laguna(汽水域研究) 29 27 - 33 2022 [Refereed]
  
• 成層化したダム湖におけるウグイ（Pseudaspius hakonensis）の生息場と環境要因との関係の解明

  長岡祥平, 黒田充樹, 南憲吏, 沖津二朗, 白川北斗, 大杉奉功, 東信行, 上田健太, 朱妍卉, 中森陸, 佐藤信彦, 宮下和士

  Laguna(汽水域研究) 29 99 - 114 2022 [Refereed]
  
• Sonic tagging reveals age and size-specific spatial variation during Pacific herring spawning migrations in northern Japan

  Makoto Tomiyasu, Hokuto Shirakawa, Yuki Iino, Daichi Oshiyama, Masahiro Ogawa, Takashi Kitagawa, Hiromichi Mitamura, Nobuaki Arai, Yoshinori Miyamoto, Keiichi Uchida, Kenji Minami, Kazushi Miyashita

  Fisheries Research 242 106020 - 106020 0165-7836 2021/10 [Refereed]
  
• Acoustic characteristics of a potentially important macroalgae, Sargassum horneri, for coastal fisheries

  Kenji Minami, Chihomi Kita, Hokuto Shirakawa, Yohei Kawauchi, Huamei Shao, Makoto Tomiyasu, Yuka Iwahara, Hideo Takahara, Takashi Kitagawa, Kazushi Miyashita

  Fisheries Research 240 105955 - 105955 0165-7836 2021/08 [Refereed]
  
• Site fidelity and return trips of visually and olfactorily inhibited black rockfish (Sebastes schlegelii) individuals tracked by acoustic telemetry

  Mitsuki Kuroda, Yoshinori Tatsu, Yuya Ueda, Hokuto Shirakawa, Kenji Minami, Kazushi Miyashita, Makoto Tomiyasu

  Journal of Marine Science and Technology-TAIWAN 29 (2) 158 - 167 2021/05 [Refereed]
  
• Development of a biomass assessment method using echo sounder for coastal fisheries

  Kenichi Kobayashi, Yanhui Zhu, Daichi Oshiyama, Kenji Minami, Hokuto Shirakawa, Kazushi Miyashita

  Journal of Marine Science and Technology-TAIWAN 29 (2) 168 - 174 2021/05 [Refereed]
  
• Seasonal dynamics in fish distribution and abundance in coastal waters of Kochi Prefecture Suzu Area by acoustic survey

  Yanhui Zhu, Kenji Minami, Yuka Iwahara, Kentaro Oda, Koichi Hidaka, Osamu Hoson, Koji Morishita, Sentaro Tsuru, Masahito Hirota, Hokuto Shirakawa, Kazushi Miyashita

  Journal of Marine Science and Technology-TAIWAN 29 (2) 146 - 157 2021/05 [Refereed]
  
• 長期間の連続観測データからみた中海の下層における溶存酸素濃度の変動特性

  金 相曄, 濱田孝治, 南 憲吏, 清家 泰

  Laguna(汽水域研究) 27 33 - 40 2020/12 [Refereed]
  
• 音響計測手法を用いた中海大根島周辺におけるオゴノリ類群落の分布と季節変化

  南 憲吏, 倉田健悟, 安永志織, 金 相曄

  Laguna(汽水域研究) 27 21 - 31 2020/12 [Refereed]
  
• Estimating fish population abundance by integrating quantitative data on environmental DNA and hydrodynamic modelling

  Keiichi Fukaya, Hiroaki Murakami, Seokjin Yoon, Kenji Minami, Yutaka Osada, Satoshi Yamamoto, Reiji Masuda, Akihide Kasai, Kazushi Miyashita, Toshifumi Minamoto, Michio Kondoh

  Molecular Ecology 30 (13) 3057 - 3067 0962-1083 2020/07/20 [Refereed]
  
• Target strength measurement of free-swimming jack mackerel using an indoor large experimental tank

  YOHEI KAWAUCHI, KENJI MINAMI, HOKUTO SHIRAKAWA, KAZUSHI MIYASHITA, YUKA IWAHARA, MAKOTO TOMIYASU, MOTOKI KOBAYASHI, TAKESHI SAKAI, HUAMEI SHAO, MASAHIRO NAKAGAWA

  NIPPON SUISAN GAKKAISHI 85 (1) 2 - 16 0021-5392 2019/01/15
• Target strength of a common kelp species, Saccharina japonica, measured using a quantitative echosounder in an indoor seawater tank

  Huamei Shao, Kenji Minami, Hokuto Shirakawa, Yohei Kawauchi, Ryuichi Matsukura, Makoto Tomiyasu, Kazushi Miyashita

  Fisheries Research 214 110 - 116 0165-7836 2019 [Refereed][Not invited]
  
• Seasonal and interannual variation in the density of visible Apostichopus japonicus (Japanese sea cucumber) in relation to sea water temperature.

  Minami, Kenji, Masuda, Reiji, Takahashi, Kohji, Sawada, Hideki, Shirakawa, Hokuto, Yamashita, Yoh

  Estuarine, Coastal and Shelf Science in press 2019 [Refereed][Not invited]
  
• 屋内大型水槽を用いた自由遊泳するマアジのターゲットストレングス測定

  川内陽平, 南憲吏, 白川北斗, 宮下和士, 岩原由佳, 富安信, 小林基樹, 酒井猛, 邵花梅, 中川雅弘

  日本水産学会誌 2019/01 [Refereed][Not invited]
  
• Stage-specific distribution of Japanese sea cucumber Apostichopus japonicus in Maizuru Bay, Sea of Japan, in relation to environmental factors

  Kenji Minami, Hideki Sawada, Reiji Masuda, Kohji Takahashi, Hokuto Shirakawa, Yoh Yamashita

  Fisheries Science 84 (2) 251 - 259 1444-2906 2018/03/01 [Refereed][Not invited]
   

  The Japanese sea cucumber Apostichopus japonicus plays important ecological and economic roles in the coastal areas of Japan. Here, we aim to reveal the relation between habitat characteristics and density of juvenile and adult sea cucumbers in Maizuru Bay. Density of adult sea cucumbers was estimated by underwater visual surveys and bottom trawls and that of newly settled individuals by seedling collectors distributed in the bay. The physical environment of the sea bottom was evaluated from median diameter, total organic carbon, total nitrogen, carbon-to-nitrogen ratio, carbon isotope ratio, nitrogen isotope ratio, depth, slope, and distance from the coastline. Adult sea cucumber density was higher in the east side than the west side of Maizuru Bay, the former having a no-take zone for sea cucumbers. Juvenile sea cucumbers were most abundantly collected in the central part of the bay. High organic matter from the sea, short distance from the coastline, and high seabed gradient (steepness) had a positive effect on the density of adult sea cucumbers, and depth had positive effects on their body size. We suggest that sustainable management of sea cucumbers can be achieved by a combination of the establishment of no-take zones and increased protection of nursery habitats.
• Verification of echosounder measurements of thickness and spatial distribution of kelp forests

  Huamei Shao, Kenji Minami, Hokuto Shirakawa, Takashi Maeda, Toshiaki Ohmura, Yoshikazu Fujikawa, Norishige Yotsukura, Masahiro Nakaoka, Kazushi Miyashita

  Journal of Marine Science and Technology (Taiwan) 25 (3) 343 - 351 1023-2796 2017 [Refereed][Not invited]
   

  Acoustic methods can be used to assess seaweed meadows. The accuracy of the methods is a key factor in the estimation of seaweed distribution and conditions. We obtained and verified thickness and spatial distribution values measured using an echosounder. We determined the thickness of seaweed growing in the coastal waters off Higashidoori-mura, Aomori, Japan on June 5-6, 2013. Acoustic data were collected using an on-board quantitative echosounder at 120 kHz. The thickness was also directly measured at 14 points. The root mean square error (RMSE) of the thickness determined by the acoustic and direct methods was calculated. A survey to determine the spatial distribution was performed in Miyako-shi, Iwate on July 18, 2014. The estimated spatial distribution was determined from the thickness data collected by the acoustic method of varied transect lines by changing transect orientation and intervals. The kelp forest distribution was also observed directly at 106 points. Then, the concordance rates of the visual observations and estimated spatial distribution were obtained. The RMSE of the acoustic and directly measured thickness of the kelp forests (Saccharina japonica), was 0.06 m, similar to the vertical resolution of the echosounder. The concordance rate between the acoustic and directly measured values was 92% when the maximum transect interval was 21 m. Smaller transect intervals yielded higher accuracy. High accuracy for the thickness and acoustically derived spatial distribution were obtained by the acoustic method when suitable thresholds were used, which has important applications for the evaluation of seaweed stands.
• The relationship between body angle and target strength of ribbonfish (Trichiurus japonicus) displaying a vertical swimming motion

  Makoto Tomiyasu, Wan-Yu Kao, Koki Abe, Kenji Minami, Taro Hirose, Michio Ogawa, Kazushi Miyashita

  ICES JOURNAL OF MARINE SCIENCE 73 (8) 2049 - 2057 1054-3139 2016/09 [Refereed][Not invited]
   

  During movement, the body angles of ribbonfish change, including a unique vertical swimming motion that influences their target strength (TS). In this study, we observed body angle changes in ribbonfish using an acceleration data logger and video recordings. Based on these data, variations in echo intensity in response to body angle changes were revealed using radiograph images of the swim-bladder and the respective TS values. The frequency of a body angle >60 degrees was 57.78% peak at 77 degrees. The swimbladders were found to be slender ellipses inclined 3-4 degrees upward from the body axis. The TS peaked (about -30 dB for the average pre-anal length of 223.9 +/- 21.8 mm) when the body angle was horizontal or inclined 2-3 degrees downward. The TS decreased substantially when the body angle was vertically inclined. From about 10 degrees upward inclination to vertical, the TS fluctuated between -50 and -60 dB. In a comparison of the average TS values among body angle categories, the TS values for body angles grouped as 'vertical' (between 60 degrees and 90 degrees), showing static mode activity patterns in video recordings, were low (-55.7 +/- 3.9 dB, Mean +/- SD), whereas those for the horizontal body angle (between 0 degrees and 30 degrees) category, comprising the active mode, were high (-47.0 +/- 8.7 dB) (P-value < 0.01). In the natural habitat, ribbonfish are known to gather at the sea floor during the daytime. In contrast, at night they disperse and move actively while foraging. Consequently, their echo intensities in natural habitats change substantially in response to their diel changes in behavioural ecology. Additional measurements or theoretical models considering the influence of ribbonfish behaviour should be undertaken as a result of this study.
• Environmental DNA as a 'Snapshot' of Fish Distribution: A Case Study of Japanese Jack Mackerel in Maizuru Bay, Sea of Japan

  Satoshi Yamamoto, Kenji Minami, Keiichi Fukaya, Kohji Takahashi, Hideki Sawada, Hiroaki Murakami, Satsuki Tsuji, Hiroki Hashizume, Shou Kubonaga, Tomoya Horiuchi, Masamichi Hongo, Jo Nishida, Yuta Okugawa, Ayaka Fujiwara, Miho Fukuda, Shunsuke Hidaka, Keita W. Suzuki, Masaki Miya, Hitoshi Araki, Hiroki Yamanaka, Atsushi Maruyama, Kazushi Miyashita, Reiji Masuda, Toshifumi Minamoto, Michio Kondoh

  PLOS ONE 11 (3) 1932-6203 2016/03 [Refereed][Not invited]
   

  Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R-2 value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10-150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a 'snapshot' of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.
• Using Acoustics to Determine Eelgrass Bed Distribution and to Assess the Seasonal Variation of Ecosystem Service

  Shiori Sonoki, Huamei Shao, Yuka Morita, Kenji Minami, Jun Shoji, Masakazu Hori, Kazushi Miyashita

  PLOS ONE 11 (3) 1932-6203 2016/03 [Refereed][Not invited]
   

  Eelgrass beds are an important source of primary production in coastal ecosystems. Understanding seasonal variation in the abundance and distribution of eelgrass is important for conservation, and the objectives of this study were to 1) monitor seasonal variation in eelgrass beds using an acoustic monitoring method (Quantitative echo sounder) and 2) broadly quantify the carbon circulation function. We obtained acoustic data of eelgrass beds in coastal areas north and east of Ikunojima Island. Surveys were conducted nine times over the 3-year period from 2011 to 2013 in order to monitor seasonal variation. Acoustic data were obtained and used to estimate the spatial distribution of eelgrass by geostatistical methods. To determine supporting services, we determined carbon sink and carbon fixation by eelgrass beds using data from the National Research Institute of Fisheries and Environment of Inland Sea (2011). The height and distribution of eelgrass beds were at a maximum in May and at a minimum in November of each year. Distribution trends were different between the north and east areas. Supporting services showed the same patterns throughout the year. The area of distribution was considered to be coincident with the life history of eelgrass. Distribution differed by area and changed yearly due to the effects of bottom characteristics and wind direction. Quantifying the supporting services of eelgrass beds was shown to be useful for managing the conservation of coastal ecosystems.
• Spatial and Temporal Distribution of Hairtail (Trichiurus japonicus) in the Bungo Channel, Japan

  KAO Wan-Yu, TOMIYASU Makoto, TAKAHASHI Ryuzo, OGAWA Michio, HIROSE Tarou, KUROSAKA Kouhei, TSURU Sentarou, SANADA Yasuhiro, MINAMI Kenji, MIYASHITA Kazushi

  The Journal of the Marine Acoustics Society of Japan 特定非営利活動法人 海洋音響学会 42 (4) 167 - 176 0916-5835 2015/10 [Refereed][Not invited]
   

  To ensure sustainable utilization of the hairtail (Trichiurus japonicus) fishery resources in the coastal and offshore waters of Japan, 15 acoustic surveys were conducted from 2007 to 2013 using a 38 kHz split-beam echo sounder. The hairtail was mainly distributed depth between 80 and 280 m in winter (particularly between 80–120 m), 60–280 m in depth (particularly between 120–160 m) in autumn, and 70–260 m in depth (particularly between 70–140 m) in summer. The average area backscattering coefficient (s_a) was higher in winter and spring between 2008 and 2009; in the other years it was highest in autumn. The average s_a was significantly influenced by depth, temperature, salinity, and turbidity in univariate analyses (p<0.05). However, in linear regression analyses, the average s_a significantly increased only with increases in temperature and salinity, whereas the effects of depth and turbidity were not statistically significant.
• 音響反射強度測定による来留見ノ瀬のホンダワラ科藻場の現存量推定と季節変化

  南 憲吏, 濱野 明, 東条斉興, 中村武史, 村瀬 昇, 安間洋樹, 宮下和士

  海洋音響学会誌 42 1 - 10 2015/01 [Refereed][Not invited]
  
• Quantitative mapping of kelp forests (Laminaria spp.) before and after harvest in coastal waters of the Shiretoko Peninsula, Hokkaido, Japan

  Kenji Minami, Naoki Tojo, Hiroki Yasuma, Yusuke Ito, Takahiro Nobetsu, Shin-ichi Fukui, Kazushi Miyashita

  FISHERIES SCIENCE 80 (3) 405 - 413 0919-9268 2014/05 [Refereed][Not invited]
   

  In the Shiretoko Peninsula, a World Natural Heritage site, the sustainable management of kelp forests has drawn public attention because of the economic and ecological importance of kelp. We spatially estimated the distributions of kelp forests in the Shiretoko Peninsula before and after harvest. Field surveys were conducted in coastal waters (23.74 km(2)) at the ends of July and August 2008, immediately before and after harvest. Data on the presence or absence and thickness of the kelp forests were collected via acoustic observation. The data were interpolated using geostatistical methods. Before harvest, the kelp forests were continuously distributed over 5.64 km(2) (thickness 33-132 cm), especially near the north part of the study area. After harvest, they were sparsely distributed over 2.73 km(2) (thickness 35-105 cm). In the southern part of the study area, the influence of harvests was observed as declines in forest area. In addition, relatively thickly forested areas formed the majority of the part most likely to be harvested. Selective harvesting for area and size was confirmed though quantitative mapping of kelp forests. The quantitative mapping of both the distribution and harvest of kelp forests was successful.
• Tilt angle and theoretical target strength of the Japanese sandeel, Ammodytes personatus, captured in the Northern coast of Hokkaido

  Safruddin, Yohei Kawauchi, Yusuke Ito, Kenji Minami, Kazuhiko Itaya, Keiji Maeda, Ryuichi Matsukura, Koki Abe, Hiroki Yasuma, Kazushi Miyashita

  The Journal of the Marine Acoustics Society of Japan 40 1 - 10 2013/10 [Refereed][Not invited]
  
• Spatial estimation of the kelp forests (Laminaria spp.) distribution in coastal waters of Osatsube Hokkaido, Japan, using acoustic method and geographic information

  Huamei Shao, Yusuke Ito, Kenji Minami, Hiroki Yasuma, Kazushi Miyashita

  GIS/Spatial Analyses in Fishery and Aquatic Sciences 5 133 - 149 2013/06 [Refereed][Not invited]
  
• Comparison of measurements and model calculations of target strength of juvenile sandeel in Sendai Bay

  Ryuichi Matsukura, Kouichi Sawada, Koki Abe, Kenji Minami, Hiroshi Nagashima, Shiroh Yonezaki, Hiroto Murase, Kazushi Miyashita

  Nippon Suisan Gakkaishi (Japanese Edition) 79 (4) 638 - 648 1349-998X 2013 [Refereed][Not invited]
   

  The target strength (TS) of juvenile sandeel (3.1-7.7 cm in standard length, SL) was measured for various tilt angles (-30° to 30°) at 120 kHz, and was compared with the theoretical TS calculated using the theoretical sound scattering model. The maximum TS measured at the tilt angle of 0° ranged from -68.8 to -60.8 dB, whereas the range of the theoretical TS was from - 68.7 to - 61.5 dB. The difference of the measured and theoretical values of the maximum TS was -1.6 to 0.9 dB, and the TS patterns showed good agreement, particularly in the range of the main lobes, in the tilt angle (-10° to 10°). The theoretical model was used to calculate the TS under the same conditions where the specimens were collected. The correlation between the SL and the maximum TS is given by the equation: TS=43.1 log SL - 96.1.
• Estimation of the spatial distribution of a Sargassum bed in Kuruminose, Yamaguchi, Japan, using an acoustic method

  Kenji Minami, Akira Hamano, Naoki Tojo, Takeshi Nakamura, Hiroki Yasuma, Kazushi Miyashita

  Nippon Suisan Gakkaishi (Japanese Edition) 78 (2) 171 - 179 0021-5392 2012 [Refereed][Not invited]
   

  Sargassum beds play important ecological roles as nursery grounds, feeding grounds and hiding grounds for coastal fauna in Kuruminose, Yamaguchi, Japan (12 km 2). In this study, we tried to estimate the spatial distribution of a Sargassum bed using an acoustic method. For this purpose, binarization and geostatistical methods were used. The binarization provided the optimum thresholds to separate the bottom and head of the Sargassum bed. The bottom threshold and the head threshold were -22.4 dB, and -56.4 dB, respectively. The horizontal distribution was interpolated every 1 m 2 using kriging. The area of the Sargassum bed was estimated to be 1.94 km2, with thickness of 0.50 to 2.24 m. The Sargassum bed in the south-southeast of Kuruminose was thicker and larger than that near Kuruminose, suggesting that the south-southeast Sargassum bed is important for the coastal ecosystem in Kuruminose. The estimated thickness and distribution corresponded with those by direct observation by diving and underwater TV camera, suggesting that acoustic measurement is adequate for estimating the spatial distribution of Sargassum beds.
• 音響手法を用いたコンブ場の厚さ計測

  南 憲吏, 安間洋樹, 東条斉興, 伊藤祐介, 福井信一, 野別貴博, 宮下和士

  数理水産科学誌 9 62 - 74 2011/12 [Refereed][Not invited]
  
• Swimming angle and target strength of larval Japanese anchovy (Engraulis japonicus)

  Yusuke Ito, Hiroki Yasuma, Reiji Masuda, Kenji Minami, Ryuichi Matsukura, Saho Morioka, Kazushi Miyashita

  FISHERIES SCIENCE 77 (2) 161 - 167 0919-9268 2011/03 [Refereed][Not invited]
   

  The swimming angle of larval Japanese anchovy (Engraulis japonicus) was measured in a tank, and target strength (TS) was calculated using a theoretical scattering model. The mean swimming angle was 12.8A degrees (SD +/- 22.1). Increased speeds of flow led to increased mean swimming angles. The mean swimming angle at flow of 5 cm s(-1) was higher than at other speeds. TS values were estimated using a distorted-wave Born approximation model for two cases. Average values were 1-3 cm s(-1) (11.5A degrees A A +/- A 22.1) and 5 cm s(-1) (16.6A degrees A A +/- A 21.7) for cases 1 and 2, respectively. For case 1, TS ranged from -92.0 to -74.7 dB with a mean of -79.4 dB at 120 kHz. For case 2, TS ranged from -92.2 to -75.2 dB with a mean of -79.9 dB. The mean TS in case 2 was lower than that in case 1, with the maximum difference being 1.0 dB at 120 kHz (standard length 22.0 mm). However, there were no significant differences between the regression lines of cases 1 and 2. Thus, changes in flow speed altered the swimming angle of larval Japanese anchovy, but had little influence on TS.
• Spatial estimatiion of euphausiid abundance of Pacific coast off Hokkaido, Japan in early summer of 2008

  Naoki Tojo, Kenji Minami, Ryuichi Matsukura, Yohei Kawauchi, Tetsuichiro, Funamoto, Masayuki Chimura, Akira Nishimura, Kazushi Miyashita

  Journal of Marine Science and Technology 19 294 - 301 2011/01 [Refereed][Not invited]
  
• Estimation of kelp forest, Laminaria spp., distributions in coastal waters of the Shiretoko Peninsula, Hokkaido, Japan, using echosounder and geostatistical analysis

  Kenji Minami, Hiroki Yasuma, Naoki Tojo, Shin-ichi Fukui, Yusuke Ito, Takahiro Nobetsu, Kazushi Miyashita

  FISHERIES SCIENCE 76 (5) 729 - 736 0919-9268 2010/09 [Refereed][Not invited]
   

  Sustainable management of the kelp forests of the Shiretoko Peninsula, a World Natural Heritage site, is necessary due to kelp's ecological and economic importance. The objectives of this study were to estimate the area of kelp forests and to clarify their spatial characteristics in coastal waters of the Shiretoko Peninsula. Data on the presence/absence and thickness of kelp forests were collected via acoustic observation on transects over about 80 km using an echosounder at 200 kHz. Acoustic data were geostatistically interpolated, and the areas covered by kelp forests were estimated. Differences in kelp distribution between the eastern and western sides of the peninsula were compared. The total area of kelp forest was 3.88 km(2) (eastern area: 3.49 km(2); western area: 0.39 km(2)). The range of thickness of the kelp forests was 34-91 cm. Many kelp forests in the eastern area were thick (>78 cm) and distributed continuously, while kelp forests in the western area were sparsely distributed.
• Shape and target strength of vesicles of two Sargassum species common to the coastal waters of Japan

  MINAMI Kenji, HAMANO Akira, NAKAMURA Takeshi, TAKAO Yoshimi, YASUMA Hiroki, MIYASHITA Kazushi

  The Journal of the Marine Acoustics Society of Japan The Marine Acoustics Society of Japan 37 (3) 147 - 155 0916-5835 2010/07 [Refereed][Not invited]
   

  The size of vesicles and amount of gas they contain is a major factor in the acoustic scattering of Sargassum plants. Here we investigate the morphological character of the vesicles and gas, and their theoretical and experimental target strength (TS) for two Sargassum species, Sargassum macrocarpum and S. siliquastrum. Both species are abundant in the coastal waters of Japan. A total of 593 vesicles were measured using a soft X-ray system, and their gas shapes were applied to two theoretical TS models (non-resonance and resonance). Experimental TS were obtained at 70 and 200 kHz using quantitative echo sounders in a freshwater tank. Gas fields were found in 418 vesicles, and the gas radius and external size of the vesicles were linearly related in both species. The theoretical TS of the non-resonance model was similar to the experimental TS of large vesicles (≥4.1 mm at 70 kHz, ≥2.8 mm at 200 kHz), whereas the theoretical TS of the resonance model was similar to the experimental TS of small vesicles (≤3.1 mm at 70 kHz, ≤1.9 mm at 200 kHz). Finally, we estimated TS-size equations according to the gas-size relationships and compared the results.
• 仙台湾周辺における計量魚探を用いた鯨類餌生物の種判別

  永島 宏, 村瀬弘人, 米崎史郎, 松倉隆一, 南 憲吏, 永木利幸, 川原重幸, 宮下和士

  宮城水産研報 8 15 - 25 2008/03 [Refereed][Not invited]
  
• Characteristics of the Measurement Accuracy by the Inclination of kinematic GPS Antenna

  Kuniharu Okuda, Kenji Minami, Kojiro Motomura, Satoru Inoue, Masatoshi Sakaide

  Journal of National Fisheries University 水産大学校 54 (2) 55 - 62 0370-9361 2006/03 [Refereed][Not invited]
   

  KGPSは約2cmの精度で測定することができる。KGPSによる測定は多くの利点があるので、その利用範囲は広まりつつある。移動体の傾斜角度を求めることもその利用方法の一つである。KGPSによって船体の傾斜角度を高精度で簡単に測定することができれば、水産分野への応用が考えられる。そのためには、KGPSによる傾斜角度の測定精度を明らかにして把握する必要がある。本論では、移動体が傾斜するとき、KGPSのアンテナも傾斜するので、アンテナ傾斜による測定精度について解析を行った。また、動揺するアンテナを基準として計算した傾斜角度についても解析した。その結果、傾斜角度に対する測定精度とその劣化精度を明らかにすることができ、移動体での測定が有効であることが分かった。

Works

• 平成30年度日本水産学会秋季大会シンポジウム「若手研究者による中国・四国地方の水産研究とこれから」

  企画責任 2018/09
• 平成30年度日本水産学会秋季大会シンポジウム「持続可能な漁業産業を支援するためのICTの活用」

  企画責任 2018/09

MISC

• 総論：持続可能な漁業産業を支援するためのICTの活用－ICT技術を社会実装するために－

  佐野稔, 宮下和士, 南憲吏  月間海洋特集 持続可能な漁業産業を支援するためのICTの活用  51-  131  -138  2019/03  [Not refereed]
  
• シラスの体形状の測定とターゲットストレングスの理論推定

  加藤謙治, 甘糟和男, 南憲吏, 邵 花梅, 小林憲一, 宮下和士  海洋音響学会2018年度研究発表会講演論文集  47  -48  2018/05  [Not refereed][Not invited]
  
• 舞鶴湾におけるマアジとカタクチイワシの環境DNAの水平・鉛直分布 口頭

  村上 弘章, 山本 哲史, 源 利文, 南 憲吏, 宮下 和士, 深谷 肇一, 尹 錫鎭, 笠井 亮秀, 澤田 英樹, 鈴木 啓太, 益田 玲爾, 山下 洋, 近藤 倫生  平成30年度日本水産学会春季大会  p.28  2018/03/27  [Not refereed][Not invited]
  
• 環境DNA定量による定量的な魚群分布調査と計量魚群探知機による検証

  山本哲史, 南 憲吏  超音波テクノ  29-  53  -58  2017/06  [Not refereed][Not invited]
  
• 計量魚探による現存量調査. 水産海洋地域研究集会「出口に向けた水産総合研究 ―豊後水道域のタチウオひきなわ漁業を例として―」

  宮下和士, 富安信, 高宛愉, 安部幸樹, 南憲吏, 濱田貴史, 竹下文雄, 高橋竜三, 三谷曜子  水産海洋研究  79-  188  -189  2015  [Not refereed][Not invited]
  
• 舞鶴湾におけるマナマコの分布密度の季節変化と生息環境

  南 憲吏, 益田玲爾, 高橋宏治, 澤田英樹, 上野正博, 山下 洋  2013年度水産海洋学会シンポジウム  2013-  p.129  2013/11/15  [Not refereed][Not invited]
  
• 計量魚群探知機を使用した藻場の分布推定

  南 憲吏  超音波テクノ  25-  15  -22  2013/11  [Not refereed][Not invited]
  
• 計量魚群探知機を用いたガラモ場の現存量推定

  南 憲吏, 安間洋樹, 濱野 明, 東条斉興, 中村武史, 宮下和士  海洋音響学会2012年度研究発表会講演論文集  1  -2  2012/06  [Not refereed][Not invited]
  
• Symposium: Marine ecosystem of the western North Pacific with special interest in cetaceans

  宮下和士, 松倉隆一, 東条斉興, 南 憲吏, 安間洋樹, 永島 宏, 小野寺恵一, 渡邉 光, 米崎史郎, 村瀬弘人  Bulletin of the Japanese Society of Fisheries Oceanography  75-  (3)  183  -184  2011/08  [Not refereed][Not invited]
  
• 音響カメラDIDSONによるクラゲおよび魚類の現存量推定値と濁度の関係

  大畑 亮輔, 益田 玲爾, 真壁 竜介, 栗原 拓也, 上野 正博, 南 憲吏, 山下 洋, 上 真一  平成23年度日本水産学会春季大会  2011/03/30  [Not refereed][Not invited]
  
• カタクチイワシシラスの遊泳姿勢とターゲットストレングスの推定

  伊藤 祐介, 守佐保, 南 憲吏, 益田 玲爾, 宮下 和士  平成22年度日本水産学会春季大会  2010  [Not refereed][Not invited]
  
• Estimation of prey preference of common minke whales (Balaenoptera acutorostrata) in a coastal component (off Sanriku) of JARPNII from 2005 to 2006

  HIROTO MURASE, SHIGEYUKI KAWAHARA, HIROSHI NAGASHIMA, KEIICHI ONODERA, TSUTOMU TAMURA, RYOSUKE OKAMOTO, SHIROH, YONEZAKI, RYUICHI MATSUKURA, KENJI MINAMI, KAZUSHI MIYASHITA, HIDEYOSHI YOSHIDA, MUTSUO GOTO, TAKEHARU BANDO, DENZO INAGAKE, MAKOTO OKAZAKI, HIROSHI OKAMURA AND, HIDEHIRO KATO  IWC JARPNII report  1  -14  2008  [Not refereed][Not invited]
  
• ホンダワラ類の気胞の音響散乱特性

  南 憲吏, 濱野 明, 高尾芳三, 中村武史, 宮下和士  海洋音響学会2006年度研究発表会講演論文集  1  -2  2006/05  [Not refereed][Not invited]
  

Research Grants & Projects

• 魚類の心理特性に注目した新たな増養殖技術基盤の開発

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2022/06 -2025/03 

  Author : 高橋 宏司, 南 憲吏, 持田 浩治

   

  本研究は、“サカナ”が持っている心理特性である「情動」に注目し、摂食行動の基盤にある摂食情動を摂餌音および赤色光刺激によって促進させることで、飼育魚の成長効率の向上を目指すことを目的とする。初年度である2022年度では、摂餌音の確認および録音・再生システムの構築を実施し、同時並行で赤光の摂食情動促進効果について検討した。水産有用魚種に適用する前に、モデル生物であるゼブラフィッシュを対象に、摂餌音・赤色刺激の実験を実施した。摂餌音については、水槽下でのゼブラフィッシュの摂餌時に特徴的な周波数の摂餌音が確認され、摂餌音の録音・再生システムを構築することができた。また、赤光刺激については、ゼブラフィッシュの摂餌行動は、赤光環境下で活発な摂餌が持続しやすい効果が確認された。水産有用種での検討では、マアジを用いて赤光が摂餌行動におよぼす効果について検討をした。赤光の照射によってマアジの摂餌量の増加効果は確認されなかったが、水面下での遊泳行動の増加効果は確認されたことから、赤光は摂餌活性を高める可能性が示唆された。