Salmon swim upstream. They spend most of their life maturing in oceans and then they migrate back to the rivers in which they were born to spawn and then die. This is a major event for bears and large birds of prey because they like salmon.

Recently scientists have begun to use micro chips to track navigation patterns of wild salmon.

“Thanks to new sound-emitting tags, combined with an extensive coastal network of underwater detectors from Alaska to California, several mysteries of fish migration and survival may soon start to unravel.”

Jim Bolger, executive director, of the Pacific Ocean Shelf Tracking (POST) Project