North Pacific Anadromous Fish Commission

Technical Report 17

Table of Contents

The Utilization of Cold-water Zooplankton as Prey for Chum Salmon Fry in Yamada Bay, Iwate, Pacific Coast of Northern Japan

Authors: 
Yuichiro Yamada, Kei Sasaki, Kodai Yamane, Miwa Yatsuya, Yuichi Shimizu, Yoshitomo Nagakura, Tadahide Kurokawa, and Hideki Nikaido

Abstract Excerpt:
After migrating into the sea from rivers, chum salmon fry stay in coastal areas during spring to early summer, subsequently migrating to the northern North Pacific Ocean (Seki 2005). The availability of prey organisms in this early marine period is one of the most important factors affecting growth and survival of salmon fry (Terazaki and Iwata 1983; Ban et al. 1996; Seki 2005). The magnitude of the Oyashio Current significantly affects the zooplankton community structure in nearshore waters during this period (Terazaki 1980; Kotani et al. 1988; Nishibe et al. 2016). Therefore, we expect that feeding habits and prey selectivity of chum fry might vary in response to fluctuations in coastal environmental conditions. In order to clarify these relationships, we analyzed the stomach contents composition of chum salmon fry and in situ zooplankton community structure during their coastal residence period using samples collected at the Sanriku coastal area for four years. Our ultimate goal is to clarify the relationship between the nearshore environment of chum fry and the adult return rate, and to subsequently develop a salmon fry release strategy to improve returns of adult salmon.

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

DOI:
https://doi.org/10.23849/npafctr17/180.183.

Citation

Yamada, Y., K. Sasaki, K. Yamane, M. Yatsuya, Y. Shimizu, Y. Nagakura, T. Kurokawa, and H. Nikaido.  2021.  The utilization of cold-water zooplankton as prey for chum salmon fry in Yamada Bay, Iwate, Pacific coast of northern Japan.  N. Pac. Anadr. Fish Comm. Tech. Rep. 17: 180–183.  https://doi.org/10.23849/npafctr17/180.183.