Researchers prepare to tag a juvenile lemon shark.
Click to see more pictures from the expedition. Tim Calver, a member of the team, is filing a series of dispatches from the field. Friday, March 10 Lama lagoon, our chosen research area, is an offshoot of the main Rocas lagoon. At its widest point, Lama Lagoon is probably only 10 or 20 meters across. At high tide it is 10 feet deep, but at low tide it is completely dry.