Each bookmark includes a full-color image in the shape of a critter — a blue crab, summer flounder, great blue heron, horseshoe crab, or red knot - with information on the backside. A surf board, which reminds swimmers to be aware of rip currents, and a wind turbine, which highlights the 2-megawatt turbine on University of Delaware's Lewes campus, round out the 6-bookmark collection.

A set containing one copy of each bookmark is free, or you can order a 50-pack of a single bookmark for $20.