Systematic assessment of worldwide marine stock enhancement and sea ranching programs

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05781
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Shuichi Kitada 東京海洋大学, 学術研究院, 名誉教授 (10262338)
• Co-Investigator(Kenkyū-buntansha): 濱崎 活幸 東京海洋大学, 学術研究院, 教授 (90377078)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 種苗放流 / 遺伝的影響 / 集団構造 / 進化 / サケ / アユ / マダイ

Outline of Final Research Achievements

We evaluated the effects of world and Japanese hatchery release programs and their impacts on wild populations. We summarized estimators of fixation index (FST), and demonstrated its validity by colonization simulation and empirical data analysis of human, cod, wild poplar. We summarized our method for unbiased estimation of stocking effectiveness by a two-stage sampling and made the R program publicly available. We organized data of the red sea bream hatchery release in Kagoshima Bay accumulated over many years and evaluated the stocking effectiveness and genetic impact. We analyzed published genetic data of salmon and inferred that the Japanese population is the most recent evolutionarily, and detected SNPs that characterize Japan populations with a significant deviation from the neutral population structure. We analyzed published genetic data of Ayu and estimated the hybridization rate of land-locked Ayu in anadromous populations in Japan to be 24±8%.

Free Research Field

水産増殖

Academic Significance and Societal Importance of the Research Achievements

本研究では、種苗放流の効果及び遺伝的影響を世界規模で客観的に評価した。これまで、放流効果を世界横断的に俯瞰した研究は無く、種苗放流の遺伝的影響を種間及び事例間で比較した研究はない。本研究により、種苗放流の効果及び遺伝的影響の顛末が、世界規模のレビュー及び個別の大量放流事例解析で初めて解明された。種苗放流の有効性について本質的な知見を提供する本研究の学術的価値は高く、社会への波及効果も大きい