By Lauren Cheramie
NOLA.com
Mark Shirley, a Louisiana Sea Grant and LSU AgCenter marine extension agent, retired in March after 41 years of service. He is known for many things during his career, but most notably, he developed Marsh Maneuvers — established in 1989 as an immersive education program for 4-H students to experience Louisiana's coast. The program motivates students toward studying coastal ecology and biological sciences.