5.45sThus begins their 1000-mile journey back to the exact stream in which they were born.
1.8sSo how do we find our way home?
1.57sNobody knows!
3.67sExperts are unsure whether salmon navigate by memory,
5ssense of smell, or by detecting variations in Earth's magnetic field.
2.52sOkay, everybody do one of those three things.