Enhancement of material cycle improvement by taper cultivation hanging facilities

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K14975
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Aquatic bioproduction science
• Research Institution: Fukui Prefectural University
• Principal Investigator: seto masabumi 福井県立大学, 海洋生物資源学部, 教授 (60360020)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 養殖施設

Outline of Final Research Achievements

Water near sea bottom around the aquaculture grounds into which a lot of nutrients flow becomes deficient in oxygen during summer stratification. We described relationship between vertical mixing rate and taper ratio around taper cultivation hanging facilities. Vertical mixing of the facilities could be explained by the vertical variation of the vortex shedding frequency and wake volume of Karman vortex streets generated on the hanging direction of the facilities. Hypoxia water behavior of stratification stage and convection stage around the aquaculture site were investigated through the numerical simulation and observed analyzing data in Lake Notoro. Based on tolerance of scallop to low concentrations of dissolved oxygen and taper cultivation hanging facilities, we developed a method for adaptive management in aquaculture grounds for Japanese scallop Patinopecten yessoensis.

Free Research Field

水産土木学

Academic Significance and Societal Importance of the Research Achievements

本研究は、垂下養殖施設の外形をテーパ化することで、施設自体に上下混合促進効果が発現し、動力装置や土木工事を伴わずに流れが緩やかな閉鎖性養殖海域の水質改善に寄与できる可能性が示唆された。垂下養殖施設を構成する網カゴは、養殖業者が使い慣れた漁具のため、維持管理に新たな技術や知識を必要とせず、貧酸素水塊挙動診断アプリを活用した養殖活動を通して、環境再生と持続的な安定生産を融合した環境再生型漁業の実現に貢献することが期待できる。