Evaluation of growth rates of juvenile chum and pink salmon in their early marine phase using the physiological and ecological techniques

2015 Fiscal Year Final Research Report

• Project/Area Number: 25450289
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Hokkaido Research Organization
• Principal Investigator: MIYAKOSHI Yasuyuki 地方独立行政法人北海道立総合研究機構, その他部局等, さけます資源部長 (70442639)
• Co-Investigator(Kenkyū-buntansha): SHIMIZU Munetaka 北海道大学, 大学院水産科学研究院, 講師 (90431337)
• Co-Investigator(Renkei-kenkyūsha): TORAO Mitsuru 北海道立総合研究機構さけます, 内水面水産試験場・道東センター, 主査 (80442672)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: サケ / カラフトマス / 成長率 / IGF-I / 耳石 / 沿岸

Outline of Final Research Achievements

To evaluate the growth rates of chum and pink salmon in their early marine life, we analyzed the otolith daily increments of juvenile chum and pink salmon and examined the effective physiological indicators for growth rates. By otolith increment analyses, the dates of ocean entry and daily growth rates can be estimated. From examining the physiological indicators, the serum insulin-like growth factor (IGF)-I can be used as a most useful indicator to evaluate the growth rates of juvenile salmon. Serum IGF-I levels in chum and pink salmon estuarine area were lower and fish in the coastal area were higher, indicating that growths of juvenile salmon was activated when they left the estuarine area and migrated to the offshore while fish of low growth stay in the estuary. Until May, IGF-I levels in pink salmon were lower than chum salmon but were higher in June, which likely reflects a higher growth rate of this species.

Free Research Field

水産増殖学、水産資源学