The San Francisco-based Mother Jones is turning 30, and as the Chroncle’s Heidi Benson reports, this investigative magazine is struggling to retain a consistent senior staff and stay out of the hole financially as its circulation declines. Editor Russ Rymer left in late July citing “philosopical differences.” Investigative editor Monika Bauerlein (left) and deputy editor Clara Jeffery (right) have been named the new editors in chief. A financial crisis earlier this year resulted in layoffs, but publisher Jay Harris says no more cuts are planned. Circulation has fallen to 230,000, down 6 percent from last year. Another problem for the magazine is that it is based on the West Coast and therefore isn’t part of the New York media scene, which means “Mother Jones can do something huge and media doesn’t comment,” said Deirdre English, who was Mother Jones’ editor from 1980 to 1986.