Long-term variation of trophodynamics in larvae and juveniles of sardine and anchovy using archive samples

2014 Fiscal Year Final Research Report

• Project/Area Number: 24658179
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: General fisheries
• Research Institution: Fisheries Research Agency
• Principal Investigator: OKAZAKI Yuji 独立行政法人水産総合研究センター, 東北区水産研究所, 主任研究員 (90392901)
• Research Collaborator: TADOKORO Kazuaki ; ICHIKAWA Tadafumi
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 仔稚魚 / マイワシ / カタクチイワシ / 食性 / 窒素安定同位体比

Outline of Final Research Achievements

We investigated gut contents and nitrogen stable isotope on the early life stage of sardine (Sardinops melanostictus) and anchovy (Engraulis japonicus) during 1970’s to 1990’s in the Mixed water region. Larvae and juveniles of sardine and anchovy fed on calanoida and poecilostomatoida copepods in 1970’s and 1990’s (1992-1998). During the period of 1980 to 1987, they consumed calanoid copepods such as Paracalanus spp.. On the other hand, juvenile sardine mainly fed on Calanus spp. during the period of sardine recruitment failure (1988-1991). Taxonomical diversity of gut contents in the 1990’s was the highest in the study period. Although changes in the nitrogen stable isotope value did not correspond with change of gut content compositions, the value had a tendency to decline with the year periods. This study showed that the first demonstration of long-term variation of feeding ecology on the early life stage of sardine and anchovy.

Free Research Field

水産海洋学