An expert panel will discuss the economic impact of tule elk on seashore ranches at a public forum hosted by the West Marin Chamber of Commerce on May 1, at 7 p.m. at the Dance Palace Community Center. The park introduced the elk into the park’s unfenced wilderness zone in 1998 but some subsequently migrated to the pastoral zone, lured by fresh forage and water. The chamber is holding the event because of concerns that…