Spatiotemporal change in growth of two populations of Asian chum salmon in relation to intraspecific interaction |
| |
Authors: | Hyunju Seo Hideaki Kudo Masahide Kaeriyama |
| |
Institution: | (1) Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate Hokkaido, 041-8611, Japan;(2) Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate Hokkaido, 041-8611, Japan |
| |
Abstract: | Spatiotemporal changes in growth patterns of chum salmon Oncorhynchus keta that returned to the Ishikari (Japan) and Namdae (Korea) rivers in 1984–1998 were investigated using scale analysis. Juvenile
chum salmon from both populations left coastal marine areas after spring at a size of over 8 cm fork length (FL). In summer,
juvenile salmon from the Namdae River entered the Okhotsk Sea at a larger FL than did Ishikari River juveniles. There were
no significant differences in annual growth between populations of 1-, 2-, and 4-year-old fish. For 3-year-old fish, however,
Namdae River salmon had significantly higher synchronous and sympatric growth than did Ishikari River salmon. Mean FL of adults
was also larger in Namdae River salmon than in Ishikari River salmon. Analysis of covariance (ANCOVA) results showed (1) negative
linear relations between FL and catch, (2) homogeneous slopes of those relations at regional and species levels, and (3) nonhomogeneous
slopes at the population level, indicating that density-dependent effects on growth were most significant at this level. We
concluded that growth of chum salmon was concurrently influenced by stronger effects of intrapopulation competition and weaker
effects of inter- and intraspecific interactions in the Bering Sea. |
| |
Keywords: | Back-calculation Chum salmon Density-dependent effect Growth variability Intraspecific interaction Scale analysis |
本文献已被 SpringerLink 等数据库收录! |
|