Jules Leon climbed into a Ford pickup truck fitted with a net, a wheeled crate he calls a “moon buggie” and a defective winch. It was March 18 and Leon was on his way to Redondo Beach — for his third call of the day. Leon, a responder with San Pedro’s Marine Mammal Care Center, checked in with lifeguards to confirm that a sick sea lion was last seen just north of the Avenue B Lifeguard Tower.