North Pacific Anadromous Fish Commission

Technical Report 17

Table of Contents

Ontogeny of Critical Swimming Speeds for Juvenile Chum Salmon

Authors: 
Yuki Iino, Takashi Kitagawa, Takaaki K. Abe, Tsuyoshi Nagasaka, Yuichi Shimizu, and Katsuhiko Ota

Abstract Excerpt:
Chum salmon (Oncorhynchus keta) is widely distributed over a large geographic range of the North Pacific Ocean (Augerot 2005). The Pacific side of Honshu Island, Japan, called the Sanriku coastal area, represents the southernmost range of the Asian population of chum salmon (Kaeriyama 1989). Chum salmon juveniles reside in the Sanriku coastal area for two months, a relatively short residence period compared to Alaskan juveniles (Irie 1990; Orsi et al. 2004). Juveniles reside in the coastal area where the sea surface temperature (SST) ranges from 5–13°C and in late May, they start their offshore migration to feeding grounds in the Okhotsk Sea (Irie 1990). Sanriku is located at a lower latitude than Hokkaido and is a long distance to the Okhotsk Sea. In addition, the offshore currents such as the Tsugaru Warmwater Current and the Chishima Current, flow in the opposite direction from which the juveniles migrate. Hence, high swimming performance is required for juveniles to overcome the offshore currents. Before offshore migration, the fork length (FL) of the chum salmon juveniles ranges from 3–8 cm, and soon after the migrations, FL reaches from 8–12 cm. It is possible that during their short coastal residence, the swimming performance may change. However, the swimming performance has not been measured across a wide body size range yet. Therefore, the effect of body size on the swimming performance of chum salmon remains unclear.

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

DOI:
https://doi.org/10.23849/npafctr17/50.52.

Citation

Iino, Y., T. Kitagawa, T.K. Abe, T. Nagasaka, Y. Shimizu, and K. Ota.  2021.  Ontogeny of critical swimming speeds for juvenile chum salmon.  N. Pac. Anadr. Fish Comm. Tech. Rep. 17: 50–52.  https://doi.org/10.23849/npafctr17/50.52.