Federal authorities investigating Sen. Ted Stevens are trolling the Alaska fishing industry for evidence of whether the powerful Republican pushed seafood legislation that benefited his lobbyist son. So far, the most public aspect of the investigation was the FBI raid on Stevens' home in July, with agents seeking evidence of the senator's relationship with a corrupt Alaska oil contractor. But authorities have also quietly amassed evidence about fishing. After serving subpoenas throughout the industry last year, investigators recently returned to Seattle, home to many of the boats and processors that bring Alaska's seafood to market. Industry officials and attorneys involved...