Scientists investigate social patterns of salmon

Each summer, millions of fish return to Bristol Bay, and then swim on to the stream where they were born to spawn, and die. Exactly what compels them to return to the right spot is unknown. But scientists think that some hatchery-raised steelhead in Oregon might hold a clue.
“Chinook salmon, Yukon Delta NWR.” Photo: Craig Springer, U.S. Fish & Wildlife Service. Via Flickr Creative Commons.Are salmon social creatures? That’s the question a pair of researchers