**FOR USE ON SUNDAY, FEB. 3, AND THEREAFTER**rFisherman Tim Calvert cleans buoys at Fishermans Wharf on Friday, Feb. 1, 2008, in San Francisco. Federal fishery regulators said this past week that the number of chinook salmon returning to the Sacramento River and its tributaries last fall was astonishingly low. That could trigger severe fishing restrictions and economic hardship for fishermen and related businesses from Central California to the Canadian border. (AP Photo/Noah Berger) FOR USE ON SUNDAY, FEB. 3, AND THEREAFTER Photo: Noah Berger