Not five years ago, several men on Pine Island and Matlacha were arrested not only for selling manatee meat, but also ibis and other wading birds. Habitat alteration and freezes account for most of the remainder of the mortalities. Sea grass beds are on a steady decline. Alterations of the natural drainage patterns in South Florida have eliminated artesian aquifers which once sprung up from the bay bottom, so fresh water sources have been eliminated. Silting has further caused a demise of vascular plants and eliminated feeding ground.
Cold water is also the enemy of manatee.
At about 68 degrees, the manatees begin to show signs of cold-water shock. When water temperatures drop below 65 degrees, manatees begin to die. Feeding sessions last between 30 and 90 minutes. Calves feed with shorter or less concentration but more frequently. Nostrils open as soon as the manatee surface and close just before it submerges.