On the third Saturday of the month, join the GTM Research Reserve docents for a beach walk at the South Beach access location. Learn about the animals that call the beach home while collecting seashells and sharks teeth. This is a "Beaches 101" experience the entire family will enjoy. After the walk, stick around and enjoy the many miles of trails or visit the GTM Research Reserve Visitor Center located at 505 Guana River Road. There is a $3 per…