MARBLEHEAD – Interim Bell School Principal Thomas DesJardins will be a candidate for the permanent post when the search begins.Superintendent of Schools Paul Dulac said Thursday that DesJardins has done “an excellent job” as interim at the two-building, 370-student school and he has asked him to apply for the permanent position, keeping a promise he made to the school community.DesJardins is expected to face stiff competition, however. The superintendent said the principal’s job was posted Nov. 29 and six candidates have already expressed interest. The deadline for applications is Dec. 30. The salary for the Bell School Principal was $92,000 last year.Desjardins was appointed interim principal last summer after serving as assistant principal at the Marblehead Veterans Middle School for the past year.Before coming to Marblehead, Mr. Desjardins served as assistant principal of the Nathaniel Bowditch School, which is a K-8 elementary school in Salem. He also served as middle school teacher from 2003-2007 in both Danvers and Andover, and he served as an elementary school teacher in Florida from 1991-2003.Dulac made mention of DesJardins as he fulfilled a promise made when he announced the appointment in August – a promise to name a search committee around December comprised of Bell School parents, teachers and community members to assist the Superintendent in the hiring of the Bell School Principal for the 2011 academic year.As far as committee seats, Dulac said, anyone interested should contact the superintendent’s office by Dec. 21.