Researcher Profile and Settings

Affiliation

• Faculty of Fisheries Sciences　Marine Bioresource and Environmental Science　Marine Environment and Resource Sensing

Job Title

• Assistant Professor

J-Global ID

• 201801013781490418

Research Areas

• Natural sciences / Atmospheric and hydrospheric science

Educational Organization

•  Bachelor's degree program　School of Fisheries Sciences
•  Master's degree program　Graduate School of Fisheries Sciences
•  Doctoral (PhD) degree program　Graduate School of Fisheries Sciences

Research Activities

Published Papers

• Broadband target strength of arabesque greenling, Pacific sand lance, and pointhead flounder

  Naizheng Yan, Tohru Mukai, Kohei Hasegawa, Jun Yamamoto, Yoshiaki Fukuda

  ICES Journal of Marine Science 81 (1) 195 - 203 1054-3139 2023/12/12 

  Abstract Measurement of target strength (TS) is important for estimating the abundance of species using fisheries acoustics. However, most researchers have only used a limited number of representative frequencies for acoustic measurements of fish without a swim bladder (bladderless fish). Here, we measured the broadband TS of three bladderless fish species, arabesque greenling (Pleurogrammus azonus), Pacific sand lance (Ammodytes personatus), and pointhead flounder (Cleisthenes pinetorum), using two broadband echosounders. TS measurements were conducted in a seawater tank over frequency ranges of 45–90 and 80–120 kHz using a tether method. Higher TS and directivity were observed at higher frequencies than at lower frequencies for pointhead flounder and arabesque greenling. However, the TS for Pacific sand lance was relatively flat over the measured frequency spectra. Additionally, the TS of pointhead flounder and Pacific sand lance could be expressed as a function of body length and the TS of arabesque greenling could be expressed as a function of body length and frequency, which could be used in fish species discriminations and size estimations.
• In situ broadband acoustic measurements of age-0 walleye pollock and pointhead flounder in Funka Bay, Hokkaido, Japan

  Kohei Hasegawa, Naizheng Yan, Tohru Mukai

  Journal of Marine Science and Technology 29 (2) 135 - 145 1023-2796 2021/05 [Refereed][Not invited]
   

  Measurements of the broadband acoustic backscattering from fish should improve acoustic discrimination between species. The pulse compression processing of broadband systems can be used tomeasure acoustic backscattering with high range resolution and improve signal-to-noise ratio. This may increase opportunities for in situ target strength (TS) measurements, the preferredmethod of collecting TS data. To evaluate the availability of TS spectra for acoustic discrimination, three Simrad EK80 wideband transceivers and split-beam transducers of 70, 120, and 200 kHz were used to collect in situ frequency responses of TS from age-0 juvenile walleye pollock and pointhead flounder, a swim-bladderless flat-fish, distributed in and around Funka Bay, Hokkaido, Japan. The single echoes were extracted frombackscattering data, and the TS spectra of the two species were obtained. However, processing of the broadband acoustic data is under discussion. To ensure the reliability of our data, the TS spectra of standard targets were also calculated. The measured TS spectra of the standard targets were close to the theoretical TS spectra. The individual TS spectra of two species included complex frequency response; however, the mean TS spectrum was relatively stable. The different characteristics of the frequency responses observed for the two species were in good agreement with reported observations. The results available for the acoustic discrimination were similar to the multi-frequencymethod, which uses two or more single frequencies. The rawTS spectra should aid in not only discriminating between species but also estimating the size of the fish.
• Acoustic discrimination between juvenile walleye pollock and pointhead flounder

  Naizheng Yan, Tohru Mukai, Jun Yamamoto, Kohei Hasegawa

  Fisheries Research 224 105434 - 105434 0165-7836 2020/04 [Refereed][Not invited]
  
• 3. Development of monitoring technique for estimating zooplankton density by size using multi-frequency profiler

  SAWADA KOUICHI, MATSUURA TOMOHIKO, MUKAI TOHRU, FUKUDA YOSHIAKI, HASEGAWA KOHEI, ABE KOKI, SASAKI KEI, YAMADA YUICHIRO

  NIPPON SUISAN GAKKAISHI 公益社団法人 日本水産学会 84 (5) 947 - 947 0021-5392 2018
• Development of an online multi-frequency profiler for monitoring zooplankton

  Kouichi Sawada, Tomohiko Matsuura, Kohei Hasegawa, Tohru Mukai, Matt Stone, Kei Sasaki, Hideki Nikaido

  2018 OCEANS - MTS/IEEE KOBE TECHNO-OCEANS (OTO) 2018 

  The density of zooplankton within bays and in inshore areas is an important environmental parameter for determining the optimal release timing of juvenile salmon (Oncorhynchus keta) from hatchery stations. This is because the juveniles remain in these areas for 1 month, during which time they feed upon zooplankton before they begin their journey to the ocean. We monitored zooplankton, water temperature and salinity from 2013 to 2017 in Yamada Bay, Iwate Prefecture, Japan, using a multi-frequency acoustic profiler collocated with temperature-salinity sensors and a depth sensor. Our observations revealed that the large zooplankton preferred by juvenile salmon are transported into the bay by the Oyashio Current. Therefore, it is important to determine the timing of this transportation. We developed an online profiler to record these events at a hatchery station in Yamada Bay.
• Monitoring the behavior of young bluefin tuna Thunnus orientalis and yellowtail Seriola quinqueradiata in set nets using ultrasonic biotelemetry

  Keiichi Uchida, Hiromichi Ogawa, Kohei Hasegawa, Yoshinori Miyamoto, Hideki Noro, Yuka Wada, Seiji Akiyama

  Nippon Suisan Gakkaishi (Japanese Edition) 84 (1) 14 - 22 1349-998X 2018 [Refereed][Not invited]
   

  As the resource management of bluefin tuna Thunnus orientalis is becoming increasingly important, a new technology for set-net fisheries to separate young bluefin tuna from other catches is needed. If behavioral diŠerences in a set net between bluefin tuna and other species could be detected, it would help to develop such new technology. In this study, we used an ultrasonic telemetry system to study the behavior of young bluefin tuna and yellowtail Seriola quinqueradiata in a set net. The results showed that bluefin tuna swim back and forth between the second bag net and the first bag net, while yellowtail swim all the way into the final net. These behavioral diŠerences could be used in the development of a technology to separate young bluefin tuna from other catches in set nets.
• Evaluation of reflection error using ultrasonic telemetry system

  K. Hasegawa, K. Uchida, Y. Miyamoto

  The Journal of the Marine Acoustics Society of Japan 海洋音響学会 44 (1) 1 - 12 0916-5835 2017/01 [Refereed][Not invited]
  
• Prototype of a simple acoustic survey system for attachment to a GPS plotter echo sounder

  Y. Miyamoto, K. Uchida, K. Amakasu, K. Hasegawa, Y. Theparoonart, M. Anongponyoskun, S. Ishikawa, Y. Minlee, T. Sasakura

  The Journal of the Marine Acoustics Society of Japan 特定非営利活動法人 海洋音響学会 43 (2) 71 - 78 0916-5835 2016/04 [Refereed][Not invited]
   

  Biological production is thriving in the coastal areas of Southeast Asia. However, resource evaluation has not progressed. In addition, the valid acoustic research needed for resource assessment is not being conducted or disseminated. Therefore, we developed a simple measurement system to perform acoustic investigations and provide basic education. We then conducted a field test in an effort to understand the distribution of fish schools in Tateyama bay, Chiba, Japan. Depth of the target research area was about 20 m. The acoustic device was composed of a GPS plotter and echo sounder (FURUNO GP1670F)+ Interface Box and PC. The concept has been used previously. However, the equipment is simple and easy to use in collecting acoustic data. First, we assumed the amount of resources for recreational boats to measure the distribution of fish using the fish finder. Results confirmed that the system was sufficiently effective.

• Development of a real-time depth monitoring system for small fishing gear using an acoustic telemetry technique

  Kohei Hasegawa, Yoshinori Miyamoto, Keiichi Uchida

  FISHERIES SCIENCE 82 (2) 213 - 223 0919-9268 2016/03 [Refereed][Not invited]
   

  A system for real-time monitoring the depth of small fishing gear was developed using acoustic telemetry to improve the efficiency of fishing operations. The system consisted of an acoustic transmitter (pinger), an omni-directional hydrophone with a depressor, and a receiver. Using a pinger equipped with a depth sensor, a fisherman can confirm whether the fishing gear is at the intended depth. The battery of the developed pinger can be replaced easily for repeated use. The performance of the system was evaluated in a field experiment. The accuracy of measured depth was 0.4 m and was constant even if the pinger was moving. In the experiment, the system could successfully monitor the pinger depth every several second. The system was implemented in hairtail trolling to examine its effectiveness. The implementation experiments revealed some issues with the system, such as the effect of signal reflections or the installation method of the hydrophone. However, the system could monitor the depth of the fishing gear continuously in real time and it operated successfully without any problem during the fishing operation. Application of the developed system is expected to aid fishermen in adjusting the gear depth easily and accurately.
• Position accuracy of ultrasonic biotelemetry system using "Inverse cross bearing"

  K. Hasegawa, Y. Miyamoto, K. Uchida, T. Kakihara

  The Journal of the Marine Acoustics Society of Japan The Marine Acoustics Society of Japan 39 (4) 163 - 172 0916-5835 2012/10 [Refereed][Not invited]
   

  Tracking system, one of the biotelemetry systems, detects signals from pingers using a receiver located on an observation boat. This system can be used without location constraints, unlike monitoring systems and positioning systems for which a receiver must be installed in the actual sea. But such a system cannot measure the pinger position in detail. In order to measure the pinger position in greater detail using a tracking system, a new method using "inverse cross bearing" was developed. This method determines the horizontal pinger position using the intersection point of more than two bearing lines from as many observation points. The vertical position of the pinger is measured by a depth sensor on the pinger itself. This system calculates the relative azimuth of the pinger using the receiving time differences among the four transducers. The GNSS compass, to convert the absolute azimuth of the pingers relative azimuth, measures the ships heading. To estimate the theoretical error factors, experiments were conducted in actual seas. The estimation results were compared to the results of the field experiments. In certain conditions, the estimated positioning accuracy was 14 m, and the measured value was 21 m. This discrepancy may be due to factors such as agitation of the ship.

Books etc

• Guide to operation of acoustic data collection system (AQFI-1301) for shallow waters

  Y. Miyamoto, K. Uchida, Y. Theparoonrat, M. Anongponyoskun, K. Thongsila, Y. Minlee, T. Sasakura, K. Hasegawa (Joint work)
  Research Institute for Humanity and Nature 2017/02 (ISBN: 9784906888351)

Conference Activities & Talks

• タチウオ曳縄漁業を対象にした漁具深度モニタリングシステムの開発

  長谷川浩平

  令和3年度日本水産学会春季大会第72回漁業懇話会講演会  2021/03
• In situ broadband acoustic measurements of 0-age walleye pollock and pointhead flounder in Funka Bay

  長谷川浩平

  The 13th Annual Meeting of Asian Fisheries Acoustics Society  2019/11
• 遺伝的アルゴリズムを用いた広帯域送受波器の素子配列の最適化

  長谷川浩平

  海洋音響学会2019年度研究発表会  2019/05
• 不規則配列を適用した送受波器のビーム特性シミュレーション  [Not invited]

  長谷川 浩平

  海洋音響学会2017年度研究発表会  2017/05

MISC

• スケトウダラ稚魚のターゲットストレングスの体長依存性および周波数特性

  閻乃箏, 向井徹, 長谷川浩平, 山本潤  日本水産学会大会講演要旨集(CD-ROM)  2023-  2023
• 懸垂法を用いたマサバの広帯域ターゲットストレングス特性

  王梓, 閻乃箏, 長谷川浩平, 向井徹  日本水産学会大会講演要旨集(CD-ROM)  2023-  2023
• 北海道噴火湾周辺海域に生息するカイアシ類,オキアミ類,タンキャク類とスケトウダラ稚魚の周波数特性

  段ぎょく, 長谷川浩平, 閻乃箏, 向井徹  日本水産学会大会講演要旨集(CD-ROM)  2023-  2023
• 多周波数音響プロファイラーを用いた噴火湾砂原沖の魚群観測

  長谷川浩平, 向井徹, 閻乃箏, 東一彦  日本水産学会大会講演要旨集(CD-ROM)  2023-  2023
• 計量魚群探知機による琵琶湖固有種アナンデールヨコエビの分布調査

  藤田航生, 石川可奈子, 永田貴丸, 閻乃箏, 長谷川浩平, 向井徹  日本水産学会大会講演要旨集(CD-ROM)  2023-  2023
• Bottom classification from backscattering data collected by quantitative echosounders in Funka Bay, Hokkaido

  大谷寛礼, 向井徹, 長谷川浩平, YAN Naizheng  海洋音響学会研究発表会講演論文集  2023-  2023
• Broadband target strength characteristics of juvenile walleye pollock

  YAN Naizheng, 向井徹, 長谷川浩平, 山本潤  海洋音響学会研究発表会講演論文集  2023-  2023
• Measurements and Theoretical Model Simulation of Target Strength of Pacific Chub Mackerel for Use in a Quantitative Sonar

  YAN Naizheng, 向井徹, 長谷川浩平, 飯田浩二, 鶴田直剛  海洋音響学会誌  50-  (4)  2023
• 全周ソナーを用いた北海道釧路沖におけるサバ類・マイワシの魚群形状の測定

  川添祐斗, 長谷川浩平, 福田美亮, 閻乃筝, 向井徹, 山口浩志, 守田航大  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• 動物プランクトンのTS推定に必要な形状パラメータの自動計測

  斉書豪, 福田美亮, 長谷川浩平, 閻乃筝, 向井徹  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• Broadband side-aspect target strength of Japanese jack mackerel and chub mackerel

  池田大典, 長谷川浩平, 向井徹, 福田美亮, YAN Naizheng  海洋音響学会研究発表会講演論文集  2021-  2021
• Wideband target strength characteristics of bladderless fishes with different body shapes

  YAN Naizheng, 向井徹, 長谷川浩平, 山本潤, 福田美亮  海洋音響学会研究発表会講演論文集  2021-  2021
• Development of the target strength measuring system using the acrylic water tank.

  福田美亮, 長谷川浩平, 向井徹, 今泉智人  海洋音響学会研究発表会講演論文集  2021-  2021
• 計量魚群探知機を用いた海底底質判別手法の検討

  藤貫雅礼, 向井徹, 長谷川浩平, 福田美亮, 閻乃筝  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• 音響手法を用いたスケトウダラ稚魚に対するフレーム型中層トロール(FMT)の採集効率の昼夜比較

  呂振, 向井徹, 藤森康澄, 飯田浩二, 長谷川浩平  日本水産学会大会講演要旨集  2019-  2019
• Study on acoustic scattering characteristics of pointhead flounder Cleisthenes pinetorum : Target strength measurements of pointhead flounder using a broadband acoustic system

  閻 乃筝, 向井 徹, 山本 潤, 工藤 尚之, 長谷川 浩平  電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  118-  (199)  33  -36  2018/08/30  [Not refereed][Not invited]
  
• Study on acoustic scattering characteristics of pointhead flounder Cleisthenes pinetorum―Characteristics of pointhead flounder observed with a quantitative echosounder―

  向井徹, YAN Naizheng, 山本潤, 長谷川浩平  電子情報通信学会技術研究報告  118-  (199(US2018 41-48))  29‐32  2018/08/23  [Not refereed][Not invited]
  
• 擬似ランダムノイズ信号を用いた超音波発信器の受信距離

  長谷川浩平, 内田圭一, 宮本佳則, 柿原利治  日本水産工学会学術講演会講演論文集  2013-  93  -96  2013  [Not refereed][Not invited]
  
• 逆クロスベアリングを用いた超音波バイオテレメトリーシステムの測位精度評価

  長谷川浩平, 宮本佳則, 内田圭一, 柿原利治, 笹倉豊喜  日本水産工学会学術講演会講演論文集  2012-  129  -132  2012  [Not refereed][Not invited]
  

Research Grants & Projects

• 計量魚群探知機を用いた北海道噴火湾に生息する海洋生物の音響判別手法の開発

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2022/04 -2025/03 

  Author : 長谷川 浩平
• Research for migration and distribution of pointhead flounder in Funka Bay, Hokkaido using acoustic methods

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2019/04 -2022/03 

  Author : Hasegawa Kohei

   

  To estimate predation pressure of pointhead flounder on juvenile walleye pollock in Funka Bay, Hokkaido, We investigated the distribution of the both species in the area. Surveys were conducted from April to June when the both species appears in the area. Relative large school of pointhead flounder and walleye pollock was observed and the distribution of the both species overlapped. The overlapping gradually became smaller in scale in May and in June. The results implied that the predation pressure of pointhead flounder on juvenile walleye pollock was largest in April.
• Elucidation of acoustic characteristics of the "floating pointhead flounder" by field and tank experiments and realization of acoustic survey of fisheries resources

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2019/04 -2022/03 

  Author : MUKAI Tohru

   

  The acoustic characteristics of pointhead flounder were investigated by field surveys and tank experiments to realize their acoustic resource survey. We accumulated basic information necessary for acoustic resource surveys and identified the optimum survey season. First, in the field survey, we examined the characteristics of the fish schools of pointhead flounder captured by the quantitative echo sounder, and found that they were patchy in the mid-water layer. Next, tank experiments were conducted to investigate the acoustic characteristics and differences in their behavior during the day and night, as a result, acoustic surveys of pointhead flounder should be conducted during the daytime. Finally, we investigated the differences in the frequency characteristics and the echo shapes by the quantitative echo sounder in field surveys of other fish species and zooplankton overlapping with pointhead flounder, and proposed the method for discriminating these species.

Educational Activities

Teaching Experience