태평양 대구(Gadus macrocephalus)의 계군분석과 서식처 이용 양상 파악을 위한 이석의 미량화학 이용

Abstract

We analyzed trace elements in sagittal otoliths to examine the habitat use patterns and for stock separation of fish populations of Pacific Cod, Gadus macrocephalus. The samples were caught by commercial fishing gears from three marine fishery grounds in the coast of Korea (Daejin in the East Sea, Baekryeong-do in the Yellow Sea, and the Jinhae Bay in the South Sea) in December 2015 and January 2016. Trace elements in the otoliths were analyzed using LA-ICPMS of the Korea Basic Science Institute. The average ratio was 3.75 ± 0.94 × 10-3 (mean ± SD) in the core of the otolith. The otolith Sr/Ca ratios ranging from 0.61 × 10-3 to 13.97 × 10-3. We conclude from the otolith Sr/Ca ratios that G. macrocephalus spawns and grows in brackish water during the early part of its life cycle, and inhabited a broad range of salinities, including seawater and brackish water, during their lifetime. nMDS analysis with 7 elements/Ca ratios in the otolith in each specimens showed that there might be two different stocks (Yellow Sea cod and East/South Sea cod) and more than two different spawning stocks in the coast of Korea. The findings of our study offer useful new information on the habitat use and stock separation of G. macrocephalus, allowing more sustainable use of the species.ery grounds in the coast of Korea (Daejin in the East Sea, Baekryeong-do in the Yellow Sea, and the Jinhae Bay in the South Sea) in December 2015 and January 2016. Trace elements in the otoliths were analyzed using LA-ICPMS of the Korea Basic Science Institute. The average ratio was 3.75 ± 0.94 × 10-3 (mean ± SD) in the core of the otolith. The otolith Sr/Ca ratios ranging from 0.61 × 10-3 to 13.97 × 10-3. We conclude from the otolith Sr/Ca ratios that G. macrocephalus spawns and grows in brackish water during the early part of its life cycle, and inhabited a broad range of salinities, including seawater and brackish water, during their lifetime. nMDS analysis with 7 elements/Ca ratios in the otolith in each specimens showed that there might be two different stocks (Yellow Sea cod and East/South Sea cod) and more than two different spawning stocks in the coast of Korea. The findings of our study offer useful new information on the habitat use and stock separation of G. macrocephalus, allowing more sustainable use of the species.