In the last few years, there's been an explosion of concern about shark populations. Because of their low birth rates, it's very easy for their populations to be reduced very quickly. |
No one knew they swam there and back every single year. Long seasonal migrations are sort of unusual for sharks as far as we we can tell. |
Salmon sharks don't seem to care how cold it is. |
The ability to follow many individuals for a year, and in some cases for two or more years, is virtually unprecedented. |