North Pacific Anadromous Fish Commission

Technical Report 17

Table of Contents

Spawning Environment of Chum Salmon in the Coastal Rivers on the Pacific Side of Northern Japan

Authors: 
Satoki Oba, Tatsuya Kawakami, Yuki Minegishi, and Jun Aoyama

Abstract Excerpt:
The environment in the spawning redds such as water temperature and dissolved oxygen is important for the growth and survival of chum salmon (Oncorhynchus keta) during their early life stages (Bjornn and Reiser 1991; Bloomer 2016). However, little attention has been paid to natural spawning and the spawning habitat of chum salmon on the Pacific side of northern Japan (the Sanriku Coast), which constitutes the southern edge of the specific range. This is because most adults returning to Japanese waters, including the Sanriku Coast, have been considered to be hatchery-origin due to the intensive implementation of the stock enhancement program. Recently, the possible importance of the wild population for the entire Japanese stock has been reported (Morita et al. 2013; Aruga et al. 2014). Moreover, the natural spawning of chum salmon on the Sanriku Coast has been observed after Great East Japan Earthquake occurred in 2011 (Aoyama 2017; Minegishi et al. 2021). We investigated, as the first step, the spawning environment of chum salmon in the Kozuchi and Unozumai Rivers on the Sanriku Coast, Japan.

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

DOI:
https://doi.org/10.23849/npafctr17/178.179.

Citation

Oba, S., T. Kawakami, Y. Minegishi, and J. Aoyama.  2021.  Spawning environment of chum salmon in the coastal rivers on the Pacific side of northern Japan.  N. Pac. Anadr. Fish Comm. Tech. Rep. 17: 178–179.  https://doi.org/10.23849/npafctr17/178.179.