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Relationships between growth traits and scale stable isotopes (δ 13 C, δ 15 N) of adult chum salmon Oncorhynchus keta in Hokkaido, Japan
Author(s) -
Kawakami Tatsuya,
Saito Toshihiko,
Nishida Keishi,
Yamakawa Takashi,
Otake Tsuguo
Publication year - 2019
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/jai.13860
Subject(s) - oncorhynchus , trophic level , δ13c , δ15n , biology , stable isotope ratio , isotopes of nitrogen , isotope analysis , isotope , isotopes of carbon , fish measurement , ecology , fish <actinopterygii> , fishery , total organic carbon , physics , quantum mechanics
Summary Stable isotope analysis (SIA) in combination with growth analysis using scales collected from adult chum salmon Oncorhynchus keta migrating back to Hokkaido, Japan, was performed to describe the variation of isotopic composition of carbon (δ 13 C) and nitrogen (δ 15 N) in scales and to examine relationships with growth traits [age, fork length (FL), and relative growth ratio in the last growth period [(RGR last )]. Scale stable isotope (SI) values in 3‐ to 6‐year‐old fish were highly variable, ranging from −17.6‰ to −14.3‰ for δ 13 C and 9.5‰ to 13.4‰ for δ 15 N. The δ 15 N was positively correlated with FL, and this tendency may indicate changes in trophic level with growth. Significant effect was not detected between δ 15 N and RGR last , it can be inferred that factors potentially yielding high δ 15 N may not necessarily result in higher growth rates. No trend found between FL and δ 13 C may imply that there is no clear segregation in feeding locations between the 3‐ to 6‐year groups. This study provided basic information for scale SI values of chum salmon adults and indicated that SIA using scales could be a new approach to elucidating the trophic ecology of chum salmon.