SEARCH

Search Details

Yamamoto Jun

Field Science Center for Northern Biosphere　Aquatic Research StationAssistant Professor

Researcher basic information

■ Degree
  • 博士(水産科学）, 北海道大学
  • 修士, 北海道大学
■ URL
researchmap URLホームページURL■ Various IDs
J-Global ID■ Research Keywords and Fields
Research Field
  • Life Science, Ecology and environment
■ Educational Organization

Career

■ Career
Educational Background
  • 1997, Hokkaido University, 水産学研究科, 研究生中退, Japan
  • 1997, Hokkaido University, Graduate School, Division of Fisheries
  • 1996, Hokkaido University, 水産学研究科, Japan
  • 1996, Hokkaido University, Graduate School, Division of Fisheries
  • 1994, Hokkaido University, School of Fisheries Sciences, 特設専攻科, Japan
  • 1994, Hokkaido University, Faculty of Fisheries
  • 1993, Hokkaido University, School of Fisheries Sciences, 漁業学科, Japan
  • 1993, Hokkaido University, Faculty of Fisheries
Committee Memberships
  • 2001 - 2003
    日本水産学会, 北海道支部庶務監事, Society

Research activity information

■ Awards
  • Nov. 2021, Asian Fisheries Acoustics Society, Young Fisheries Acoustician Award
    Broadband target strength measurements of three bladderless fishes.
    Yan N, Mukai T, Hasegawa K, Yamamoto J and Fukuda Y
  • Dec. 2017, 日本DNA多型学会, 優秀研究賞
    時岡駿;柳本卓;山本潤;桜井泰憲
  • Apr. 2016, Best student Award, Best student Award
    YAMAMOTO Jun
■ Papers
■ Other Activities and Achievements
■ Books and other publications
  • Todarodes pacificus
    Sakurai Y; Kidokoro H; Yamashita N; Yamamoto J; Uchikawa K; Takahara H, 249-272
    Nova Science Publishers, Inc., 2013, [Joint work]
■ Syllabus
  • 水圏科学特論Ⅱ, 2024年, 修士課程, 環境科学院
  • ﾌｨーﾙﾄﾞ科学基礎論, 2024年, 修士課程, 環境科学院
  • 環境と人間, 2024年, 学士課程, 全学教育
  • 海洋生物科学実験Ⅱ, 2024年, 学士課程, 水産学部
  • 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育
  • 科学・技術の世界, 2024年, 学士課程, 全学教育
  • 海洋資源科学実験Ⅲ, 2024年, 学士課程, 水産学部
  • 沿岸実習Ⅰ, 2024年, 学士課程, 水産学部
  • 沿岸実習Ⅱ, 2024年, 学士課程, 水産学部
  • 水産科学英語Ⅰ, 2024年, 学士課程, 水産学部
  • 国際交流Ⅱ, 2024年, 学士課程, 国際本部
  • 英語演習, 2024年, 学士課程, 全学教育
  • 北方生物圏生態科学, 2024年, 学士課程, 水産学部
■ Affiliated academic society
  • 水産海洋学会
  • 日本水産学会
■ Research Themes
  • How does ocean heat wave affect marine animal populations? Understanding the mechanisms of polymorphism in squid.
    Grants-in-Aid for Scientific Research
    01 Apr. 2024 - 31 Mar. 2028
    岩田 容子; 時岡 駿; 山本 潤; SANCHEZSILVA LUISGUSTAVO
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 24K01834
  • 最先端複合化学分析で明らかにするイカ類回遊生態：環境変動応答の理解の深化に向けて
    科学研究費助成事業
    01 Apr. 2024 - 31 Mar. 2028
    石村 豊穂; 山本 潤; 瀬戸 陽一; 坂本 達也; 浅沼 尚; 鈴村 明政
    日本学術振興会, 基盤研究(A), 京都大学, 24H00523
  • 親イカ由来の細菌と溶存態有機物（DOM）に着目したスルメイカ初期餌料の解明
    科学研究費助成事業
    01 Apr. 2023 - 31 Mar. 2026
    山本 潤; 足立 亨介; 柳本 卓; 中屋 光裕
    日本学術振興会, 基盤研究(B), 北海道大学, 23K26975
  • 多元素同位体の複合解析による回遊生物の新たな生物地球化学タグの確立
    科学研究費助成事業
    20 May 2022 - 31 Mar. 2025
    石村 豊穂; 山本 潤; 西田 梢; 則末 和宏; 田副 博文
    日本学術振興会, 学術変革領域研究(B), 京都大学, 22H05029
  • Study on the first food of Todarodes pacificus paralarvae focus on bacterial transmission between and mother-to-paralarvae
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2020 - 31 Mar. 2023
    山本 潤; 足立 亨介; 柳本 卓; 中屋 光裕
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 20H03055
  • Elucidation of acoustic characteristics of the "floating pointhead flounder" by field and tank experiments and realization of acoustic survey of fisheries resources
    Grants-in-Aid for Scientific Research
    01 Apr. 2019 - 31 Mar. 2022
    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.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 19K06201
  • Development of shrimp pot with escape vent to prevent the catch of small individual of Corn-stripe shrimp in Funka-Bay, Hokkaido
    Grants-in-Aid for Scientific Research
    01 Apr. 2018 - 31 Mar. 2021
    Fujimori Yasuzumi
    This study investigated a method to improve selectivity of shrimp pot aiming to protect the stock of Coonstripe shrimp Pandalus hypsinotus in the Funka-Bay, Hokkaido. It was found that small individuals were particularly active at night from the water tank experiment to investigate the behavior and diurnal activity. This suggested mesh size expansion and the installation of escape gap on pot for exclusion of small shrimp would be effective.
    The mesh selectivity of the pot was estimated by water tank experiments, and it was elucidated that 35 mm mesh size was suitable to protect individuals with 20 mm carapace length which correspond to the size of recruitment. Also, we confirmed that the circular escape gap with an inner diameter of 25 mm was expected to exclude the carapace length of 30 mm which correspond to the size after sexual conversion.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 18K05775
  • Study on use of microbial loop by Japanese flying squid paralarvae
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2016 - 31 Mar. 2019
    YAMAMOTO Jun; SAKURAI Yasunori
    The present study examined the first food of Todarodes pacificus paralarvae by assuming that the paralarvae consume microorganisms which were produced by biological loop. The bacterial profile of the egg masses which were obtained through natural spawning in a large experimental tank was similar to those of the nidamental gland (the secretary organ of adult). This result suggested that the adhering bacteria might have originated from indigenous or symbiotic bacteria of the nidamental gland. While， metagenome analysis (CI1 and 16S-rRNA) on the gut contents which were extract from wild paralarvae by Laser Micro-dissection showed that the gut contents were consist of many species of eukaryote and prokaryote (the results on eukaryotic results may require additional testing). The result suggested paralarvae intake microorganism called “detritus”.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 16H04963
  • Development of quantitative monitoring method for zooplankton inhabiting the ocean twilight zone
    Grants-in-Aid for Scientific Research
    01 Apr. 2014 - 31 Mar. 2018
    MUKAI TOHRU
    This application was aimed at developing a method of quantifying zooplankton inhabiting the ocean twilight zone with depths of 200 to 500 meters using a combination of the acoustic and the optical method. Using the acoustic method, besides krill, which has many examples of measurements up to now, it was also possible to measure the acoustic scattering cross-section which is the scale factor in quantification for copepods and amphipods. On the other hand, with the optical method, it was possible to photograph zooplankton at depths of up to 100 meters using a general-purpose digital camera with external flash. Further shooting at greater depths could not be realized due to troubles in the equipment.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 26660151
  • Studies on stock fluctuation of seasonal cohorts of Japanese flying squid related to the success of reproduction and recruitment
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2013 - 31 Mar. 2016
    Sakurai Yasunori; YAMAMOTO Jun
    The experiment was conducted to test the reproductive hypothesis of Todarodes pacificus in a large tank (200 tons). The maturation process untill spawning were controled by temperatures during 13 and 20°C. Ripe females and males were released into the large tank.The egg masses were observed suspended in the thermocline. However, without the thermal gradient,egg masses collapsed on the bottom, and eggs were infested by microbes.Twenty-one females spawned 39 egg masses (30 to 120 cm diameter).The paralarvae survived for up to 13 days, which was suggested that they fed on DOM with marine bacteria.
    Annual catches of fall cohort are gradually decreasing after 2000s.The inferred spawning area was covered by warm surface water above 24°C . However, annual catches of winter cohort are stable after 2000s. The inferred spawning area was formed along continental slope in the East China Sea. The fishing area shifted to more northern area and the southward migration was delayed by December.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 25292117
  • A new method of measuring the size of fish on the image from digital camera
    Grants-in-Aid for Scientific Research
    01 Apr. 2012 - 31 Mar. 2015
    FUJIMORI Yasuzumi; YAMAMOTO Jun
    This study aims to develop a new method of measuring the size of fish on the image from camera. The tank experiment was conducted using a digital camera and laser unit that generate flat beam. Further, sea experiment was done preparing a measuring system installed to watertight case that has capability of 300 m sea depth.
    The measurement error was 4 % in mean and up to 5 % in the tank experiment. In the sea experiment, the measuring system was hanged underwater from the ship. The fish that recognized as walleye pollock was observed. The estimated length accorded with the size of walleye pollock distributed in the experimental area.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 24580254
  • Initiation of sustainable trap cage fisheries improved by observation of behaviors of North Pacific giant octopus
    Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    01 Apr. 2012 - 31 Mar. 2014
    SAKURAI Yasunori; NORO Kyosei; YAMAMOTO Jun
    North Pacific giant octopus is caught by the trap cage for octopus in the coast water of northern Japan. However, the catch is gradually decreasing after 2000. The causes were estimated by the bycatch of small octopus under 3kg BW and cannibalism between octopuses in cage.
    The aim of this study is to develop improved trap cage for escaping the small octopus. We observed some behaviors of giant octopus in captivity, such as entering into cage, positioning in cage, aggressive behavior and cannibalism between octopuses in cage. After that, we attached the several size of circular ring in the side net of cage. We found that small octopus under 3 kg can escape through the ring of 55 mm in diameter in the side net from cage. We also examined octopus behavior around the setting trap cages by biologging methods. Then, we confirmed that 3 kg octopus was not caught by the improved trap cage. This new trap cage will be more useful for the local octopus fisheries management in the northern Japan.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 24658164
  • クラゲ異常発生の行方とその大量の死骸が海洋生態系へ与えるインパクトの解明
    科学研究費助成事業
    2008 - 2010
    山本 潤; 向井 徹
    本研究では主に大型クラゲを対象にし,近年,連続して発生している大型クラゲの異常発生に伴う,その大量の死骸が海洋生態系へ与えるインパクトを解明することを目的としている。初年度である20年度は,海底に沈降後の大型クラゲの死骸に誘引される生物を撮影するための一定間隔で撮影を行うタイム・ラプス・カメラシステムを2器作製してテストを実施してきたが,大型クラゲの大量発生はなく実海域での実験はできなかった。21年度は,本種が日本海に大量に出現する10月に北海道大学水産学部附属練習船おしょろ丸の日本海実習航海時に,隠岐諸島の南東の水深約240mの点にて,上記タイム・ラプス・システムを用いて,大型クラゲ死骸に誘引される生物の観察を行った。その結果,死骸が海底に到達してまもなく(約10分後)から,腐肉食者であるクモヒトデ,巻貝がクラゲ死骸に集まるのが観察できた。
    最終年度である22年度は、当該大型クラゲの大発生が予測されたが、限定的な発生にとどまった。このような状況ではあったが、発生期の10月下旬におしょろ丸にて日本海の南西部において目視観測を実施したが、その分布は認められなかった。本研究で明らかにした水中におけるクラゲの音響散乱特性を考慮して、日本海において計量魚群探知機を用いてクラゲを探査したが、当該大型クラゲおよびクラゲに集まる他の生物との対応を認めることはできなかった。クラゲの異常発生は、今後、発生する可能性の非常に高い問題であり、本助成が終了した後も、実施する予定である。
    日本学術振興会, 挑戦的萌芽研究, 北海道大学, 20651002
  • Prediction of short- and long-term stock fluctuations of Japanese common squid, Todarodes pacificus related to climate change
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2007 - 2009
    SAKURAI Yasunori; YAMAMOTO Jun; MORI Ken; KIDOKORO Hideaki; GOTO Tsuneo
    We used the new reproductive hypothesis to explain and predict the stock structure or stock fluctuation related to climatic regime shifts and global warming scenario during the 20^-21^ Century. We conclude that short and long-term change of T. pacificus stock can be explained and predicted by physical parameters such as SST, and bottom topography during the spawning period based on this new reproductive hypothesis. Based on this method, we can then monitor the trend of stock fluctuation and structural change such as a seasonal shift of the spawning period related to abrupt changes of the inferred spawning areas. As an example, we present how to monitor the recent seasonal changes of inferred spawning areas and predict the stock condition of the next year cohort. Further, we try to predict the fate of T. pacificus during the 21st Century based on the Global Warning Scenario (IPCC, 2007) using the Earth Simulation System (FRCGC, Frontier Research Center of Global change, Japan). The inferred main spawning grounds still occur from the southern Japan Sea and the East China Sea by 2099. However, the peak of spawning period will shift from October-February in 2005 to November-March in 2050, and December-April in 2099.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 19380105
  • Development of adaptive marine ecosystem management and co-management plan in Shiretoko World Natural Heritage Site : Interaction between land and marine ecosystems
    Grants-in-Aid for Scientific Research
    2006 - 2009
    SAITOH Sei-ichi; KAERIYAMA Masahide; SAKURAI Yasunori; MATSUDA Hiroyuki; WATANUKI Yutaka; MIYASHITA Kazushi; KONO Tokihiro; KUDO Hideaki; HIRAWAKE Toru; SHIOMOTO Akihiro; YAMAMOTO Jun
    We carried out the development of monitoring methods on marine life and their environment and promoted various field observations in Shiretoko World Natural Heritage (SWNH) area. As a result, it is clear that there is difference in primary production system between northern coastal region and southern coastal region. We clarified 1) the effect of Pacific salmon (Genus Oncorhynchus) escapement on supply of marine-derived nutrients to the riparian ecosystems using the stable isotope analysis, and 2) to estimate escapement dynamics and spawning carrying capacity of the wild pink salmon (O.gorbusha) relating to the feeding behavioral pattern of brown bear (Ursus arctos) in SWNH area. Based on the adaptive marine ecosystem management, we proposed new method to evaluatean optimum fisheries operation for each fish species using both catch of fish and haul of fish in the Shiretoko coastal fisheries.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 18201006
  • 音響技術を用いた水中映像定量化技術の開発
    科学研究費助成事業
    2005 - 2007
    向井 徹; 山本 潤
    本研究では,水中ロボットカメラ(ROV)によって得られた水中映像に計量魚群探知機による音響映像を組み合わせ,水中映像の定量化技術の開発を開発することを目的としている.さらに,近年,注目されている現象を対象とし,その現象のメカニズム解明のための基礎的なデータを取得することも目指し,本研究では,その被害が問題となった日本海の大型くらげを主な対象として研究した.具体的には,平成18年度に北海道大学水産学部付属練習船おしょろ丸(船底装備の計量魚群探知機を装備)の日本海調査(9月下旬〜10月上旬)に乗船し,北海道奥尻島沿岸から本州・日本海沿岸域で大型くらげの目視調査を行った.ROVによる大型くらげの観察は,目視観察により大型くらげが高密度で分布する海域で実施した。この調査では,船上から,水中遊泳するクラゲの視認が困難である場合も,ROVを用いることにより,その鉛直的な分布特性のデータを取得することができ,さらに,これらの大型クラゲの分布深度では,計量魚群探知機においても,大型クラゲからのエコーを確認することができた。平成19年度では,単なるエコーグラム上での確認ではなく,その分布密度,サイズを検出するために,クラゲの音響的な特性を解析した。その結果,クラゲの音響散乱強度は,体サイズよりも周波数や遊泳姿勢などに強く影響を受けることが明らかになった。今後,ROVによって遊泳姿勢とサイズを測定し,音響データと併せて解析することによリクラゲの浮遊分布の定量化が可能となると考えられる。また本研究で解析した手法を他の魚種,プランクトンなどに応用することによって,水中映像の音響データによる定量化が十分可能であると考えられる。本研究の成果は現在投稿中である。
    日本学術振興会, 萌芽研究, 北海道大学, 17658082
  • 発生期で変動パターンが異なるスルメイカ資源変動機構の解明
    科学研究費助成事業 若手研究(B)
    2005 - 2007
    山本 潤
    本研究では,本種の秋および冬発生群の示す資源変動パターンが,"再生産時期の秋から冬にかけての冷却の進行と,経年的な冬季の冷却強度が卵塊・ふ化幼生の生残に影響する"との見地に立ち,スルメイカの資源変動のメカニズムを解明することを目的として実施した.今年度では,これまでのスルメイカの生活史における知見(ふ化幼生の正常遊泳水温範囲,産卵海域の水深,海洋構造との関係)を基に,衛星画像,気象データ,海底地形データより,スルメイカ幼生の生残海域を,地理情報システム(GIS)の手法を用いて,主産卵場である東シナ海における,10月から3月までの当該海域の空間的,時間的な変化を解析した。今年度では,さらに精度を上げるために気象庁が作成した衛星画像再解析データ(MGDSST)を用いた。
    その概略は
    ・東シナ海では,10月から3月にかけて季節風の速度の増加とともに気温が下がり,海面を冷却している。
    ・ふ化幼生の生残可能海域は,秋生まれ群が発生する10月から11月までは対馬暖流の影響下の東シナ海の陸棚上にあり,冬生まれ群が発生する1月から3月までは,黒潮が卓越する黒潮の影響下にある。
    ・秋生まれ群,冬生まれ群は,対馬暖流と黒潮の二つの輸送経路に分かれるかを解明。
    ・結果的に,本種はこの輸送経路の切り替わりによって,生残に不適な生物・物理環境への輸送,索餌,被食などを分散させる,bed-hedging戦略をとっていることが明らかになった。
    これからのことから,秋生まれ群は相対的に生産力が低いが変動が小さい日本海へ,冬生まれ群は,変動が生産力は高いが変動の大きな太平洋側へと輸送されることによりその変動パターンが異なることが明らかになった。本成果は只今,国際雑誌に投稿中である。
    日本学術振興会, 若手研究(B), 北海道大学, 17780145
  • Reproduction and Recruitment Success of the Japanese Common Squid, Todarodes pacificus, related to Annual and Seasonal Changes of Winter Wind Stress and Mixed Layer Depth.
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2003 - 2005
    SAKURAI Yasunori; SAITOH Sei-ichi; BOWER John R.; YAMAMOTO Jun
    Recruitment success in squids depends largely on environmental conditions at the spawning and nursery grounds. The autumn and winter spawning groups of Japanese common squid, Todarodes pacificus have the largest biomass and the annual catch of winter groups have fluctuated widely. T.pacificus produces gelatinous, nearly neutrally buoyant egg masses that contain many small eggs. The egg masses are thought to occur within or above the pycnocline at temperatures suitable for egg development (e.g., 15-23℃ in T.pacificus) and under conditions of reduced predation. After hatching, the paralarvae presumably ascend to the surface layer and are advected into convergent frontal zones We observed something resembling a T.pacificus egg mass within the pycnocline at 70-120 m depth (temperature range : 18-21℃) in the Tsushima Current using an ROV. We also estimated from laboratory studies that hatchlings ascend to the surface at temperatures of 18-23℃. We used this new reproductive hypothesis to estimate winter spawning areas of T.pacificus. Results of a previous study suggested that annual catches of T.pacificus increased during periods of weak winds and warm air temperature, suggesting that the strength of winter winds may affect recruitment. The spawning areas of winter spawning group during warm regime after 1990's were estimated to be along the continental edge off the Kyushu Island and the Nansei Islands. Inner flow of Kuroshio will transport paralarvae in surface layer from the spawning areas to the nursery areas of northeastward along the continental edge. However, the spawning areas during cool regime during 1980's were reduced along the continental edge. We can present a scenario for how stock size in T.pacificus might fluctuate due to environmental factors such as sea surface temperatures and suggest how to forecast the stock fluctuation related to climatic regime shifts and global warming.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 15380127
  • Stock Fluctuations throughout Reproduction and Recruitment Process of the Japanese Common Squid, Todarodes pacificus, related to Climate Changes
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2000 - 2002
    SAKURAI Yasunori; BOWER John R.; ISODA Yutaka; SAITOH Sei-ichi; YAMAMOTO Jun
    In short-lived squids, recruitment success most likely depends on the physical and biological environments at the spawning and nursery grounds. No egg masses have been observed in the natural habitat. During 2000-2002, MOCNESS and an ROV were used to examine the distribution of egg masses and paralarvae of Todarodes pacificus in the Sea of Japan. Gelatinous egg masses were observed at two stations in the Tsushima Current along the continental shelf off the Oki Islands in November, 2000. They occurred within the pycnocline (75 and 95 m depth, respectively), where temperatures were about 18℃, which was suitable for embryonic development. Upon hatching, paralarvae may rise to the surface layer, where they would be carried into the convergent frontal zone in the Tsushima Current.
    Annual catches of T. pacificus, have markedly increased since the late 1980s, and recent catches have equaled those of the 1960s. The winter spawning area of T. pacificus in the East China Sea shrank when adult stocks decreased during a cool regime that occurred before 1988, and that its fall and winter spawning areas extended and overlapped in the Sea of Japan and East China Sea when adult stocks increased during a warm regime after 1989. Successful hatching from egg masses was to be higher when the mixed layer depth (MLD)is shallower than the bottom depth. We examined the relationship between annual catch of the winter-spawning stock, and wind speed and air temperature in the East China Sea in February during 1980-2000 to determine how a series of calm and warm winters might promote a stock increase related to changes in the MLD. Annual catches markedly increased during a decade of weak wind speed and warm air temperature from the mid-1980s to mid-1990s, suggesting that the strength of winter wind stress affects the winter-spawning stock fluctuations in T. pacificus.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 12460080
  • Study on the sampling properties of the plankton nets.
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    2000 - 2002
    SAKAOKA Keiichiro; YONETA Kunisaburo; SHIGA Naonobu; MEGURO Toshimi; BOWER John; YAMAMOTO Jun
    Plankton nets have been used for as a method for collecting the plankton. Especially, the NORPAC-NET is widely used in order to keep the compatibility of the data and there are many long-term data based on the NORPAC samples. NORPAC-NET sampling is easy to operate, the wire angles often exceed 40 degrees when sea condition is rough. These would suggest that these samples were estimated over or less than the normal condition. Then, this study investigates the collection characteristic of the NORPAC net and the property of the long-term data set. Furthermore, the present study examines other plankton net, MTD-Net, Bongo-Net and the retention on the survey-net mesh.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 12660158
  • スルメイカ類幼生の最適生残のための生物・物理環境の検出
    科学研究費助成事業 奨励研究(A)
    1998 - 1999
    山本 潤
    本研究では、今年度に以下の調査を実施した.
    1.1999年11月上旬〜中旬に隠岐諸島周辺海域においてスルメイカ幼生の分布特性調査を実施
    2.2000年2月上旬〜中旬にハワイ諸島周辺海域におけるアカイカ類幼生分布調査を実施
    1の調査は、鳥取県水産試験場試験船第一鳥取丸を用いて行った。幼生の採集は、多段式プランクトンネットを用いて、0、0-25、25-50、50-75、75-100mの5層について、計14点で実施した。深度別に採集された幼生の分布は、ふ化直後と考えられる外套長1mm未満の幼生が、海表面近くの0-25m層に最も多く出現し、幼生の外套長が大きくなるにつれて、その分布深度が深くなる傾向が認められた。スルメイカの産出卵塊は弱い沈降性を示すことが飼育実験より報告されているが、本調査の結果から、スルメイカ幼生は海表面近くでふ化し、成長するにしたがって下方へと拡散(移動)することを示唆し、産出卵塊が海表面近くに存在した可能性を示していた。本調査結果については、平成12年度日本水産学会春季大会と2000年7月上旬に英国アバディーンで開催される国際頭足類諮問機構で口頭発表する予定である。
    2の調査は、北大水産学部練習船北星丸を用いて、ハワイ諸島周辺におけるアカイカ・トビイカ幼生をボンゴネットを用いて採集し、海洋環境と幼生分布との対応を調べた。
    日本学術振興会, 奨励研究(A), 北海道大学, 10760111
  • 再生産機構に関わる海洋生物の資源変動解析
    Competitive research funding