Effect of modified magnetic field on the ocean migration of maturing chum salmon, Oncorhynchus keta |
| |
| Authors: | A. Yano M. Ogura A. Sato Y. Sakaki Y. Shimizu N. Baba K. Nagasawa |
| |
| Affiliation: | (1) Graduate School of Science and Technology, Chiba University, Inage, Chiba 263, Japan, JP;(2) Tohoku National Fisheries Research Institute, Fisheries Agency of Japan, Shinhama, Shiogama, Miyagi 985, Japan, JP;(3) Graduate School of Engineering, Chiba University, Inage, Chiba 263, Japan, JP;(4) Faculty of Engineering, Chiba University, Inage, Chiba 263, Japan, JP;(5) National Research Institute of Far Seas Fisheries, Fisheries Agency of Japan, Orido, Shimizu, Shizuoka 424, Japan, JP |
| |
| Abstract: | To investigate the role of magnetic compass orientation in oceanic migrating chum salmon, Oncorhynchus keta, an ultrasonic telemetry study was carried out in the western North Pacific off the coast of Kushiro, Hokkaido. Four salmon were fitted with a tag which generated an artificial magnetic field and modified the geomagnetic field around the head of the fish. Initially, the free-ranging salmon with stomach-implanted ultrasonic transmitters were tracked for a period of several hours before the magnetic field was altered for a period of 16 h. The generator produced an alternating magnetic field intensity of about 6 gauss, with polarity which reversed every 11.25 min. There was no observable effect on the horizontal and vertical movements of the salmon when the magnetic field was modified. However, it was noted that salmon slowed their swimming speed significantly before changing direction, regardless of whether the fish were swimming under the normal geomagnetic field or whether they were swimming under the modified field. Received: 6 April 1997 / Accepted: 29 April 1997 |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
