In The Manatee Scientists, John Reynolds does an aerial count of manatees from the Florida sky; Lucy Keith spends a weekend rescuing manatees trapped in a dam in Senegal; and Fernando Rosas takes the author on an Amazonian boat trip, looking for a young manatee he released back into the wild, with emotional results. These scientists are working hard to save manatees: docile, large sea mammals who are eaten in some parts of the world, feared in others,...