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Takatsu Tetsuya

Faculty of Fisheries Sciences　Marine Bioresource and Environmental Science　Marine Bioresource ScienceProfessor

多獲性海産魚類の資源量変動機構を明らかにするために，卵・仔稚魚の生活史を研究しています。

Researcher basic information

■ Degree
  • Doctor (Fisheries), Hokkaido University, Dec. 1998
■ URL
researchmap URLホームページURL■ Various IDs
ORCID IDJ-Global ID■ Research Keywords and Fields
Research Keyword
  • スケトウダラ
  • ホッケ
  • キアンコウ
  • トヤマエビ
  • ソウハチ
  • プランクトン
  • クモヒトデ
  • マダラ
  • 日周輪
  • 耳石
  • 耳石日周輪
  • 餌密度
  • 水産学
  • 鉛直分布
  • 水塊
  • 生態
  • 仔魚
  • 成長速度
  • 卵
  • 加入
  • 食性
  • 分布密度
  • 成長率
  • イカナゴ
  • 初期生活史
  • 卓越年級群
  • 孵化日組成
  • 水温
  • アカガレイ
  • 行動
  • 稚魚
  • 分布
  • マコガレイ
  • 成長
  • ソリネット
  • 魚類生態学
  • Early Life Histories of Marine Fishes (6301)
  • Population Dynamics of Fisheries Recources (6301)
  • Fish Ecology (6301)
Research Field
  • Life Science, Aquatic bioproduction science
■ Educational Organization

Career

■ Career
Career
  • Apr. 2010
    Faculty of Fisheries Sciences, Hokkaido Univ., Division of Marine Bioresource and Environmental Science, Laboratory of Marine Bioresource Science, Professor
  • Apr. 2006 - Mar. 2010
    Faculty of Fisheries Sciences, Hokkaido Univ., Division of Marine Bioresource and Environmental Science, Laboratory of Marine Bioresource Science, Associate Professor
  • Apr. 1995 - Mar. 2006
    Graduate School of Fisheries Siences, Hokkaido Univ., Laboratory of Marine Biorecources Ecology, Assistant Profeser
  • Jul. 1992 - Mar. 1995
    Faculty of Fisheries, Hokkaido Univ., Laboratory of Principals of Fishing Ground, Assistant Profeser
Educational Background
  • Apr. 1991 - Jun. 1992, Hokkaido University, Graduate School of Fisheries, Doctor Course
  • Apr. 1989 - Mar. 1991, Hokkaido University, Graduate School of Fisheries, Master Course
  • Apr. 1988 - Mar. 1989, Hokkaido University, Faculty of Fisheries, Specialized Training Course
  • Apr. 1984 - Mar. 1988, Hokkaido University, Faculty of Fisheries, Fisheries Science
Committee Memberships
  • Mar. 2025 - Present
    The Japanese Society of Fisheries Science, board member, Society
  • Aug. 2023 - Present
    Hokkaido Oshima Sea-area Fisheries Adjustment Committee, Committee member, Autonomy
  • Mar. 2023 - Present
    Fisheries Oceanography Associate Editor, Society
  • Apr. 2020 - Present
    The Japanese Society of Fisheries Science, Hokkaido Branch Secretary, Society
  • Apr. 2018 - Present
    水産増殖学会, 評議員, Society
  • Mar. 2018 - Present
    水産海洋学会, 理事, Society
  • May 2021 - Mar. 2024
    Japanese Society for Aquaculture Science, Vice President, Society
  • May 2021 - Mar. 2023
    水産海洋学会, 編集委員会委員長, Society
  • Apr. 2013 - Aug. 2019
    日本水産学会, 編集委員, Society
  • Apr. 2013 - Mar. 2017
    水産海洋学会, 編集委員, Society
  • 2008
    日本水産学会, 北海道支部庶務幹事（2008年度）, Society
  • Apr. 1995 - Mar. 1996
    日本水産学会, 北海道支部庶務幹事（1995年度）, Society

Research activity information

■ Awards
  • Jul. 2024, Fisheries Oceanography (Wiley), Top Downloaded Article during its first 12 months of publication in Fisheries Oceanography
    Effect of egg size on the growth rate and survival of wild walleye pollock Gadus chalcogrammus larvae. Fisheries Oceanography, 2022, DOI: 10.1111/fog.12575
    K. Kajiwara;M. Nakaya;K. Suzuki;Y. Kano;T. Takatsu
  • Mar. 2018, The Japanese Society of Fisheries Oceanography, Dr. Uda Award
    Early life histories and population dynamics of demersal fishes in subarctic waters
    TAKATSU Tetsuya
  • Jun. 2017, Fisheries Oceanography, Wiley, Reviewer Award of Fisheries Oceanography in 2016
    TAKATSU Tetsuya
  • Mar. 2015, Hokkaido University, Award for Primary Education in Hokkaido University
    TAKATSU Tetsuya
  • Mar. 2012, Plankton Society of Japan, Best Paper Award of the Plankton Society of Japan
    Feeding habits of two-flatfish-species larvae in Funka Bay, Japan. – importance of Oikopleura as prey -
    YUTARO HASHIMOTO;AKIKO MAEDA;YUSUKE OONO;YOTA KANO;TETSUYA TAKATSU
  • 2003, 平成14年度日本水産学会奨励賞
  • 2003, Achievement Award for Young Scientist: The Japanese Society of Fisheries Science Awards 2002
  • 2000, パイセス第９回年次総会(PICES IX)ベストポスター賞
  • 2000, North Pacific Marine Science Organization, 9th Annual Meeting; Best Poster Award
■ Papers
■ Other Activities and Achievements
■ Books and other publications
  • 道南おさかな図鑑
    魚に魅せられた北大の研究者たち; 井尻成保; 今村 央; 浦 和寛; 河合俊郎; 工藤秀明; 清水宗敬; ジョン・バウアー; 髙津哲也; 東藤孝; 富安 信; 中屋光裕; 平松尚志; 藤本貴史; 宗原弘幸; 山村織生; 山本 潤, マダラ，スケトウダラ，ソウハチ，マコガレイ，クロマグロ，トヤマエビ，アカガレイ，カタクチイワシ
    海文堂出版, Oct. 2023, 9784303800116, 97p, Japanese, 35734205
  • 卓越年級群 : カレイとタラの生残戦略
    髙津, 哲也
    海文堂出版, Mar. 2022, 9784303800079, 127p, Japanese, 35734170;10554227;27825138, [Single work]
  • 水産科学・海洋環境科学実習（北海道大学水産学部練習船教科書編纂委員会編）
    中屋光裕; 髙津哲也, 魚類・ベントス測定
    海文堂出版, Jul. 2019, [Joint work]
  • Anniversary Book of Hokusui Public Foundation
    TAKATSU Tetsuya, Educational contribution of Hokusui Foundation
    Hokusui Public Foundation, 2011, [Contributor]
  • カイアシ類学入門－水中の小さな巨人たちの世界（長澤和也編）
    東海大学出版会, 2005
■ Lectures, oral presentations, etc.
■ Syllabus
  • Introduction to Fisheries Sciences Ⅰ（水産科学汎論Ⅰ）, 2024年, 修士課程, 水産科学院
  • Introduction to Fisheries Sciences Ⅱ（水産科学汎論Ⅱ）, 2024年, 修士課程, 水産科学院
  • 資源生物学特論Ⅱ, 2024年, 修士課程, 水産科学院
  • 資源生物学特論Ⅰ, 2024年, 修士課程, 水産科学院
  • 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
  • 環境と人間, 2024年, 学士課程, 全学教育
  • 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
  • 海洋生物科学科沿岸実習, 2024年, 学士課程, 水産学部
  • 魚類生産生態学, 2024年, 学士課程, 水産学部
  • 水産資源各論, 2024年, 学士課程, 水産学部
  • 海洋生物科学実験Ⅳ, 2024年, 学士課程, 水産学部
■ Affiliated academic society
  • 日本水産学会
  • 日本魚類学会
  • 日本水産増殖学会
  • 日本プランクトン学会
  • 水産海洋学会
  • The Ichthyological Society of Japan
  • The Japanese Society for Aquaculture Research
  • The Plankton Society of Japan
■ Research Themes
  • Effects of marine heatwaves on the early survival processes of walleye pollock and Pacific cod: a test of the growth and prey quality-quantity hypothesis
    Grants-in-Aid for Scientific Research
    Apr. 2024 - Mar. 2028
    Tetsuya TAKATSU
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, 24K09047
  • 噴火湾における底生生物資源と漁場環境に関する研究
    公益財団法人北水協会研究助成事業
    Apr. 2011 - Mar. 2025
    坂岡桂一郎; 亀井佳彦; 大木 淳之; 阿部泰人; 大西広二; 久万健志; 木村修
    公益財団法人北水協会, 公益財団法人北水協会, Principal investigator
  • Detection of maternal effects using field-collected Pacific cod larvae and juveniles and its application to resource management
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Apr. 2021 - Mar. 2024
    TAKATSU Tetsuya; NAKAYA mitsuhiro
    本研究の目的は，産業重要種であるマダラGadus macrocephalusの野外採集仔魚から「母親効果」を検出し，母親効果を考慮した漁獲への変更が，資源量回復にどの程度貢献するのか解明することである。また，環境変動が資源量変動におよぼす影響も同時解析することで，母親効果を利用した資源保護策の有効性も明らかにする．
    まず，これまでのマダラの親魚量と着底期までの仔稚魚の生残率の関係を明らかにするために，主要産卵場の一つである青森県陸奥湾の1989年から2019年までの両者の豊度の間で累積的生残率を推定し，その年変動を明らかにした．その結果，累積的生残率は仔魚期の前半にあたる2月下旬から3月中旬の水温が高いほど高く，仔魚期の後半と稚魚期にあたる3月下旬から5月下旬の水温が7.6℃で最大値を示すことを明らかにした。水温はそれぞれ全変動の23%と22%を説明した。
    次に，孵化仔魚の耳石輪紋に形成される孵化チェック（通常より太い日周輪）の大きさが，卵径に比例するか明らかにするために，2022年1月に津軽海峡で採集した成熟魚を用いて人工授精・飼育を行い，孵化直前の卵と孵化直後の仔魚を得た。また成熟魚の体長や年齢，栄養状態が卵径におよぼす影響を明らかにするために，耳石による年齢査定と魚体測定を行った。
    野外採集仔魚は2021年4月と2022年2月に，主要産卵場である青森県陸奥湾でプランクトンネットによる採集を行った。同時に物理環境データと，仔魚の餌生物であるかいあし類ノープリウスの採集を行った。
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, 21K05723
  • Effects of egg size, larval growth rate, and juvenile nutritional condition on population dynamics of walleye pollock
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Apr. 2016 - Mar. 2019
    TAKATSU Tetsuya; NAKAYA Mitsuhiro
    To clarify survival processes in Japan Pacific Stock (JPS) of walleye pollock Gadus chalcogrammus, maternal effect and somatic condition were investigated in Funka Bay in 2016-2018. No annual difference in hatch-check diameter on larval otolith derived from maternal was observed between three year-classes. Notochord lengths in late February and early March were small in low water temperature years. The 75-77% of settled juveniles collected in mid-June have settlement checks around their otoliths and settled fork-lengths were estimated at 67.2-69.0 mm from the relationship between fork length and otolith diameter. Feeding intensities and somatic conditions of juveniles decreased in Tsugaru Warm Current water from August to October, then those recovered with water temperature decreasing after October. Annual fluctuations of somatic condition and growth rate might influence the recruitment of JPS.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 16K07834
  • Occurrence mechanism of strong-year classes in flathead flounder Hippoglossoides dubius by the assessment of transport process and prey abundance for larvae and juveniles
    Grants-in-Aid for Scientific Research
    2013 - 2015
    Takatsu Tetsuya; HOSHI NAOKI; NAKAYA MITSUHIRO; ISODA YUTAKA; INAGAKI YUTA; KANO YOTA; NAKATANI TOSHIKUNI; SUZUKI KOTA; TAMURA JUN'ICHI
    To clarify the occurrence mechanism of strong-year classes in flathead flounder Hippoglossoides dubius, transport process of pelagic larvae and juveniles and settled area of juveniles were investigated in Funka Bay and its vicinity in 2013-2015 FY. In May 2013, late pelagic stage larvae were collected with MOHT- and FMT-nets around the area off Muroran City located at the north-east end of the bay, but no larva was collected in 2014-2015. It might be important for the recruitment success in the 2013 year-class that the clockwise vortex off Muroran captured the larvae was retained by the predominantly northwesterly winds. In this vortex, suitable water temperature (4.1-5.6 degrees Celsius) and prey abundance were observed for larval growth. In contrast in August-December through 2013-2015, no settled juvenile was collected on the sea floor with an otter trawl net in and out of the bay with <98-m and 95-354-m bottom depths, respectively.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, Competitive research funding, 25450269
  • Verification of the turbulence and light-intensity hypotheses on larval survival of flathead flounder
    Grants-in-Aid for Scientific Research(基盤研究(C))
    2008 - 2011
    Tetsuya TAKATSU; Yutaka ISODA; Naoto KOBAYASHI
    Faster-growing larvae of flathead founder Hippoglossoides dubius in the initial feeding stage showed higher survival rate than slower-growing ones within cohort in Funka Bay, Hokkaido. The larvae of 2007 year-class that experienced warm-water-temperature condition showed the fastest growth in 2007-2011 year-classes. Contrary to expectations, the 2008 year-class that showed slowest-growing in larval stage became a strong year class in mature stage. Growth rate in the initial feeding stage was weakly correlated with wind speed as a turbulence indicator however did not with water temperature, global solar radiation, or density of copepod nauplii as principal prey for flathead founder larvae. Match-mismatch and growth-mortality hypotheses in initial feeding stage have some degree of validity but are insufficient to explain the variability seen in recruitment. The survival in later stage may determine the recruitment success.
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Principal investigator, Competitive research funding, 20580189
  • イカナゴ仔魚の餌生物環境と生残仮説の検証
    科学研究費補助金(若手研究(B))
    2003 - 2005
    高津 哲也
    イカナゴAmmodytes personatusの加入量予測を可能とするために,2003〜2005年に陸奥湾に出現した浮遊仔魚の分布密度,成長様式,成長率と生息環境を評価し,初期生残にかかわる諸仮説を検証した。1,湾口部の産卵場から湾内に輸送されるイカナゴ仔魚の密度は,湾内への津軽暖流水の流入量に依存していた。2,耳石日周輪解析によって求めた仔魚の孵化日組成は,3年間で若干のずれがみられたが,おおむね2月下旬から4月中旬に孵化した個体が多かった。3,摂餌開始期のイカナゴ仔魚の主要餌生物であるカイアシ類ノープリウスと,大型仔魚が捕食するカイアシ類コペポダイトおよび尾虫類は,3年間ともに仔魚が捕食すると考えられる時期には低密度であり,ミスマッチとなっていた。4,本研究における水温範囲(3.9-10.2℃)では,水温が高いほど仔魚の成長率も増加した。また,採集日直前の5日間の耳石の残差成長率も水温と有意な正の相関を示したが(r=0.15,P=0.03),カイアシ類ノープリウスの密度(範囲:13.0-35.0個体・L^<-1>)とは有意な相関はなかった(P=0.55)。5,24日齢以下の仔魚(主に脊索屈曲完了前仔魚)のうち,高成長率個体に偏って多く生残しており,低成長率個体は被食されやすいか,摂餌能力が低いために死亡しやすいものと推定された。陸奥湾におけるイカナゴ浮遊仔魚の生残には,湾内への輸送,高水温によって成長停滞が生じないこと,ボトムアップ効果が働いて餌密度が高まることの3条件をすべて満たす必要があり,いずれが欠けても高い生残率は期待できないことが明らかになった。近年の漁獲量の低下も,低水温化でよく説明できた。
    文部科学省, 若手研究(B), 北海道大学, Principal investigator, Competitive research funding, 15780129
  • Analytical Method for Nutirtional Condition of Marine Fish Larvae by Individual
    Grants-in-Aid for Scientific Research(基盤研究(C))
    2003 - 2004
    Yasuhiro ANDO; Tetsuya TAKATSU
    A sensitive and convenient procedure for fatty acid analysis of marine fish larvae has been developed in order to determine docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents as an indicator of their nutritional condition. Fatty acid content and composition in each individual of the wild marine fish larvae have been analyzed by the new procedure.1.High-performance liquid chromatography (HPLC) of fatty acid 9-anthrylmethyl esters was introduced to the new procedure. Highly sensitive fluorescent detection of the esters enabled the analysis of one eye and somatic part from one individual.2.Some processes of the analysis were modified to reduce time-consuming complicated operations. All processes after lipid extraction could be carried out in a single disposable glass vial. The analysis was completed within 3.5 hours, and about ten samples could be analyzed in one day.3.Somatic part of the 326 individuals of wild fish larvae (18 species) caught in the Funka and Mutsu Bays, Japan, were subjected to the fatty acid analysis. In all individuals, remarkable fatty acids were only five components, DHA (18-32 %), palmitic acid (18-27 %), EPA (4-19 %), octadecenoic acid (7-12 %) and stearic acid (4-23 %).4.DHA contents of the somatic part (μg/individual) were summarized for every nine individuals classified by body lengths. Coefficient of variance (CV) was high in the 2.4-3.1 and 4.4-5.2 mm brown sole (CV 0.6-1.0) and 4.8-6.0 mm Japanese anchovy (CV 0.7-0.9). Pacific sandlance showed generally lower CV (0.2-0.5 with one exception 0.9). The contents of DHA essential for marine fish larvae widely vary at specific stages during development of wild marine fish larvae.
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Coinvestigator not use grants, Competitive research funding, 15580153
  • 複合多点状態計測によるベントス・稚魚分布密度の高精度推定法の開発
    科学研究費補助金(萌芽研究)
    2003 - 2004
    木村 修; 高津 哲也; 清水 晋
    1.袴形フレームの採集過程ビデオ録画式軽量ソリネット(ソリ部内幅100cm,全長130cm,全高125cm,重量約40kg,抗力約40kg)を設計・試作した。袋網は網口100cm×50cm,全長は400cmで,総ナイロンもじ網(8×8×140経)1脚約3mmである。ナイロンもじ網ならびに網口部補強帆布は柔軟性がないので,網口下部は直接着底する構造ではない。接地性を良くするため,起こしチェーンに捕集網地(ナイロンラッセルもじ網1脚約1mm)をつけた掃底着底具を網口下部に付加した。海底を照明するため,超高輝度白色LED(5W)2個を用いた自動点灯水中ライト(全長11cm×6cmφ,重量360g)を設計・試作した。2.水深100m前後の沖合域で,防水試験と試験撮影を行った。試作水中ライト2灯つけることにより,海底でもシャッター速度1/100s,感度18dBで小型デジタルカメラレコーダに鮮明なカラー映像を録画することができた。底質が泥では泥煙幕に隠れて網口映像を撮影することができなかったが,砂や砂礫では海水の透明度が高く,映像は鮮明であった。3.映像の画像処理系への取り込み,採集効率や距離換算手法を開発した。録画テープに記録されたタイムコードで映像を指定することにより,複数の着底曳網時の画像データを自動取得した。砂礫底での画像から,全長6cm程度の魚類やヒトデ類を容易に判別できたが,エビ類の判別は困難であった。現在,ビデオ画像を合成して,着底曳網した連続海底平面画像を作成中である。この画像から,採集効率,曳網距離の推定が可能になる。4.曳網速度によって,ソリネットの姿勢や接地状況等がどのように変化するか動作試験を実施した。船速を2knotとし,ワイヤー送出・巻き揚げ速度1m/sで投揚網し,ワイヤー送出速度0.5mで曳網した。向かえ潮では着底後にしゃくるような曳網速度の変動が表れ,曳網状態は充分に安定しないこともあったが,総じて着底時も,その後も良好な接地曳網状態を維持した。曳網中,ソリネットは岩礁に乗り上げたが,姿勢を崩すことなく岩礁を乗り越えて着底した。
    文部科学省, 萌芽研究, 北海道大学, Coinvestigator not use grants, Competitive research funding, 15658055
  • Feeding habits of marbled sole larvae and juveniles in the coastal areas of Tsugaru Strait, Hokkaido
    Grants-in-Aid for Scientific Research(基盤研究(C))
    1999 - 2001
    Toyomi TAKAHASHI; Tetsuya TAKATSU; Toshikuni NAKATANI
    To clarify the survival strategy of larval and juvenile marbled sole Pleuronectes yokohamae, spatial and temporal distributions, food abundance in environment, feeding strategy, growth pattern, and predation were investigated in the coastal area of Tsugaru Strait.1. A northward-inshore compensatory drift of deeper water in Hakodate Bay was induced by strong wind in March. Larvae would be transported from the offshore spawning ground to the inshore nursery area by this compensatory drift. Eye-migrating larvae settled mainly on 3-15 m depth bottom, and juveniles concentrated at 5m depth.2. Initial foods of larvae were tintinnids and rotifers, and then shifted to copepod nauplii. Feeding success depended on water temperature rather than prey densities. Eye-migrating larvae shifted their main foods from cladocerans to harpacticoids. Low feeding intensity of these larvae would be caused by rapid changes in morphology.3. Biased feeding on adult males of harpacticoids might have been caused by a behavioral difference in harpacticoid sexes. The main food organisms of juveniles (> 30 mm in standard length) changed from harpacticoids to benthic gammarids, cumaceans, tanaidaceans, and polychaetes.4. Larvae and juveniles were swallowed by a shrimp Crangon uritai. The vertical distributions of these two organisms were more overlapped during the cold spring, increasing the opportunists for predation. This phenomenon seemed to be one of the causes of the interannual fluctuation in recruitment.5. In rearing tanks, C. uritai fed on juveniles at night. Relative high abundance of Nipponomysis sp. would restrict and reduce the predation on juveniles by C. uritai in field6. Growth rings in otoliths were validated as daily increments.Large biomass of marbled sole would be sustained in the strong current, due to demersal and adhesive eggs, larval metamorphosis at small size, and warming by Tsugaru Warm Current. Further investigations needed to assess various mortalities quantitatively.
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Coinvestigator not use grants, Competitive research funding, 11660172
  • カレイ・ヒラメ類，タラ類等の海産仔稚魚の初期生活史と生残過程，卓越年級群発生機構の解明
    その他の研究制度
    1992
    Competitive research funding
  • Ecologies of marine-demersal fish eggs, larvae, and juveniles; Mechanisms of occurrences of dominant year classes of fishes.
    The Other Research Programs
    1992
    Competitive research funding
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