A coalition of Florida environmental groups has hired lawyers to sue U.S. and state officials, who they say are failing to protect the endangered manatee, a gentle vegetarian marine mammal. Failure to enforce boating restrictions, coastal development and destruction of habitat are causing unnecessary deaths of scores of manatees, says Fran Stallings of the Save the Manatee Club. "The laws to protect this species are already on the books -- we want enforcement." Named in the suit is U.S. Secretary of the Interior Bruce Babbitt, the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service. Many manatees are crushed by canal floodgates or killed by powerboats.