|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences >
Peer-reviewed Journal Articles, etc >
Upstream migration mechanisms of juvenile temperate sea bass Lateolabrax japonicus in the stratified Yura River estuary
| Title: | Upstream migration mechanisms of juvenile temperate sea bass Lateolabrax japonicus in the stratified Yura River estuary |
| Authors: | Fuji, Taiki Browse this author | | Kasai, Akihide Browse this author →KAKEN DB | | Yamashita, Yoh Browse this author |
| Keywords: | saltwedge intrusion | | river ascending | | catadromous migration | | juvenile |
| Issue Date: | Mar-2018 |
| Publisher: | Springer |
| Journal Title: | Fisheries Science |
| Volume: | 84 |
| Issue: | 2 |
| Start Page: | 163 |
| End Page: | 172 |
| Publisher DOI: | 10.1007/s12562-017-1167-0 |
| Abstract: | Hydrographic conditions and distributions of juvenile temperate sea bass Lateolabrax japonicus were observed in early spring from 2009 to 2012 in the Yura River estuary, which is highly stratified due to its small tides and consequent seawater intrusion into the bottom layer of the river as a salt wedge. In all four studied years, the upstream expansion of their distribution coincided with the timing of the salt wedge intrusion from the lower to upper estuary, indicating that juvenile fish used salt wedge intrusions to ascend the estuary in early spring. However, juveniles sometimes remained in the nearshore area even when the salt wedge intrusion had already occurred, indicating that other triggers are also likely to be necessary. We therefore evaluated the effects of temperature on upstream migration behaviors. The relationship between the mean temperature they experienced from hatch until starting the ascent and mean age of each cohort at the upstream migration fitted with the law of effective cumulative temperature. Most cohorts ascended the river at an effective cumulative temperature of approximately 500 °C–days. This suggests that higher temperatures would lead to a shorter period prior to the upstream migration. |
| Rights: | The final publication is available at www.springerlink.com via http://dx.doi.org/10.1007/s12562-017-1167-0. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/72721 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 笠井 亮秀
|
