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Upstream migration of chum salmon through a restored segment of the Shibetsu River
Author(s) -
Akita M.,
Makiguchi Y.,
Nii H.,
Nakao K.,
Sandahl J. F.,
Ueda H.
Publication year - 2006
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2006.00153.x
Subject(s) - oncorhynchus , fish <actinopterygii> , upstream (networking) , fishery , fish migration , water column , biology , ecology , computer network , computer science
– A segment of the Shibetsu River was restored to reconstruct the ecological condition of the previously canalized river stretch to a more natural, meandering state. In this study, we investigated the upstream migration of chum salmon ( Oncorhynchus keta ) using radio transmitters to track the horizontal position of fish and data loggers to detect the vertical swimming depth of fish, simultaneously. The monitored salmon travelled near the bottom of the water column and along the riverbanks, and tended to hold in deep, slow current areas in the canalized river. In the restored segment, the fish swam at more shallow depths and against stronger currents. Although the three tracked fish all reached the confluent point and chose to enter the restored segment, they did not remain in the segment for long. This indicates that the restored area facilitates the upward migration of the chum salmon.