Dawn and dusk dives help tuna find their way home

摘要

Tuna dive fast and deep twice a day because they use an internal compass to navigate, a new study suggests.rnIt has long been known that tuna dive around dawn and dusk but no one has been quite sure why. To find out Jay Willis at the University of Tasmania In Hobart, Australia, and colleagues attached tags to 21 southern blue fin tuna (Thunnus maccoyll) and used them to monitor water temperature, time, depth and light levels for 135 days {Behavioral Ecology and Soclobiology, DOI: 10.1007/s00265-009-0818-2).