Florida and estimated that the likelihood of either population falling under 500 adults within 100 years was about 0.42%. The projected improvement of population numbers and stability is contingent on continued intervention and monitoring efforts. Collision with watercraft Over 20% of manatee mortalities per year are a result of watercraft collisions. Between 1985 and 2017 53% of adult manatee mortalities were the result of boat strikes. 96% of adult Florida manatee carcasses have scars from a boat collision with some individuals showing signs of 10 or more boat strikes. Manatees can hear boats, but they oftentimes do not have enough time to get out of the way of a fast approaching boat. A boat going at a slower speed gives the manatee more time to react and move out of the way. Manatees respond to approaching vessels by orienting towards deeper waters and increasing their speed, but they are nevertheless frequently struck as they don't have the ability to swim very fast and in shallow habitat they oftentimes don't have anywhere to go to get out of the way. Over half of all watercraft deaths are caused by the impact trauma from the hull of a fast-speeding boat, whereas the remaining percentage is caused by the boat propeller. Aerial surveys of Florida manatee and boat distribution have been conducted to map the areas in which collisions are most likely to occur, accounting for environmental and seasonal factors. Watercraft can frequently avoid hitting manatees simply by reducing speed, allowing time for the manatee to escape out of range. Despite improvements in modeling and changes to local regulations, manatee mortalities from watercraft collisions continue to rise with an all-time high of 137 recorded deaths in 2019. Loss of warm-water habitat Projected long-term loss of warm-water habitats presents a significant risk to manatees, who are unable to tolerate temperatures lower than for prolonged periods of time. Florida manatees frequently congregate around natural warm-water springs, as well as the warm discharge given off by power plants throughout the winter months. However, as older plants are replaced with more energy-efficient structures, manatees could become at risk of cold-induced death due to reduced availability of warm-water refuges. Manatees exhibit high site fidelity and can recall previous refuge sites to which they frequently return in successive winters. Some conservationists fear that manatees may become overly reliant on warm-water locations generated by power plants that may shut down