MARBLEHEAD-Four incumbent selectmen and five incumbent members of the Recreation and Parks Commission will seek re-election in May.As of 12:30 p.m. Friday, incumbent selectmen Jackie Belf-Becker, Judy Jacobi, James Nye and William Woodfin face challenges from Michael Rockett, Rose Ann Wheeler McCarthy, Christopher Hartley and Karin Martin. Selectman Harry Christensen plans to step down this spring.Incumbents Recreation and Parks Commissioners Charles Nyren, Charles Osborne Jr., Linda Rice Collins, Derek Norcross and Sam Ganglani have taken out papers for re-election. So far they face no challenges.Members of the Board of Selectmen and Recreation and Parks Commission serve one-year terms.With four weeks to go before the March 22 filing deadline, incumbent School Committee member Jonathan Lederman faces challenges from Jennifer Schaeffner and Kathy Leonardson. Committee member Amy Drinker has not taken out papers for re-election.Other incumbents who have taken papers out include Town Clerk Robin Michaud, Town Moderator Gary Speiss, and Anne McCarthy, Board of Assessors, Helaine Hazlett, Board of Health, Robert Bryne, Housing Authority, Philip Sweeney and Maura Phelan Murnane, Trustees of Abbot Public Library, Calvin Crawford and Walter Homan, Municipal Light Commission, Wilbur Bassett and P. Carlton Siegel, Water and Sewer Commission and Richard Coletti, Cemetery Commission. Appointee David Cashman has taken out papers for the remaining two years of a term on the Cemetery Commission.