With more than three decades as a marine biologist tucked under his waders, Dr. Joe Richardson has studied beaches from Nova Scotia to the Bahamas, but he still never ceases to marvel at the diversity of Tybee Island’s shores. The widely published professor emeritus of marine sciences at Savannah State University delights in sharing his knowledge about these lively shores, and to that end hosts walking tours for groups of all ages that incorporate conversation and hands-on activities. As his followers comb their fingers and toes through the sand of the beaches and inlets, they search for fossilized shark teeth and animals that Dr. Joe helps identify. He also discusses the tides, sand layers, local marine life, and which creatures eat with salad forks or soup spoons. Along the rock jetty, groups splash into tide pools to learn about the intertidal zone and the ways animals adapt to this habitat, then help Dr. Joe collect live specimens for a field aquarium by pulling in a 50-foot beach seine net and examining the fish and crabs caught in its weave. Lucky guests can glimpse the sleek fins of dolphins, and curious ones can ask Dr. Joe about his research projects, current ecological concerns, and how mermaids keep their fingers from getting pruny.