Carlos from Valencia asks, “Do heatwaves affect fishes’ otoliths, causing them to become disoriented, and interfering with the migration process?”
Karin Hussy, from the Technical University of Denmark, replies:
“A heatwave, which generally lasts for a limited period of time, has no effect on the development of otoliths. Movements during heatwaves are the result of physiological stress, which causes fish to require more food and to find colder water.
It’s true that under normal nutritional and temperature conditions, fishes’ otoliths grow at the same speed, but otherwise there would be a disconnection which would cause the otoliths to become larger, in relative terms. In any case, this is a long-term process that is not related to temporary heatwaves.”