In addition, if a power plant shuts down or fails to produce sufficient warm water, the water temperature may drop dangerously low, which occurred between December 1989 and January 1990 during a prolonged cold snap. Florida power companies have been responsive to the needs of manatees. For example, after its Caloosahatchee River plant in Ft. Myers shut down temporarily in the mid-1980s, putting hundreds of manatees at risk, the Florida Power and Light Company drilled wells into the groundwater and installed pumps to bring warmer water to the surface in the event the plant shuts down again in winter. F. Meanwhile, manatees face other perils.
Manatees also drown in gill nets, or get trapped in canal locks or floodgates.
Scientists use the distinctive and plentiful scars to identify and track individual manatees that have survived such run-ins. Florida initiated manatee protection legislation as early as 1893, and in 1978 enacted the Manatee Sanctuary Act, which designated the entire state as a refuge and sanctuary for manatees. This act makes it unlawful for anyone to annoy, molest, harass, or disturb the animals and allows for enforcement of boat speed regulations in certain areas. Until recently, none of these laws proved particularly effective in stemming the loss of manatees. Recent gains are likely the result of increased public awareness, a better understanding of manatee population ecology, and greater enforcement of manatee protection guidelines, such as restrictions on boat speeds.