North Pacific Anadromous Fish Commission

Technical Report 17

Table of Contents

Downstream Migration and Spatial Distribution of Juvenile Chum Salmon in the Otsuchi Bay, the Sanriku Coast of Iwate, Japan

Authors: 
Tatsuya Kawakami, Yuki Minegishi, and Jun Aoyama

Abstract Excerpt:
Chum salmon (Oncorhynchus keta) is one of the most commercially valuable species in Iwate prefecture, located on the Sanriku coast. However, the annual catch of adult chum salmon in Iwate has drastically decreased after a peak in the 1990s despite the massive effort of releasing hatchery fishes (Hokkaido National Fisheries Research Institute, Japan Fisheries Research and Education Agency 2021). This decreasing trend has continued in the last decade under a marked decline in the adult return rate. The mortality that occurred during their early marine life, which is influenced by coastal environment and juvenile condition, is suggested as a significant factor to regulate the adult return rate of Japanese chum salmon (Saito and Nagasawa 2009). Also, the Great East Japan Earthquake that occurred in 2011, which devastated the coastal environment and salmon hatchery, is supposed to be one of the causes of this decline (Watanabe et al. 2015). Therefore, there is an urgent need to clarify the linkage between early mortality of chum salmon and the coastal environment for enhancing the sustainable use of chum salmon resources in Iwate.

*This is the first paragraph of an extended abstract. Download the full abstract below.

DOI:
https://doi.org/10.23849/npafctr17/176.177.

Citation

Kawakami, T., Y. Minegishi, and J. Aoyama.  2021.  Downstream migration and spatial distribution of juvenile chum salmon in the Otsuchi Bay, the Sanriku Coast of Iwate, Japan.  N. Pac. Anadr. Fish Comm. Tech. Rep. 17: 176–177.  https://doi.org/10.23849/npafctr17/176.177.