Tampa , Florida ( CNN ) -- The unusually cold weather that struck Florida in January did more than damage crops and citrus trees . It has also caused an unprecedented number of deaths among Florida 's beloved residents , the endangered West Indies manatees . Twisting and flopping in the shallow water , Baby Coral probably does n't realize just how lucky she is . When this 3-year-old female manatee was brought into Tampa 's Lowry Park Zoo last month , she was 300 pounds underweight , unable to eat . Her skin was covered with small white , blister-like lesions known as `` Florida frostbite , '' the result of exposure to cold temperatures . Lowry Park Zoo is one of the three facilities in the state that provide medical treatment and a place for manatees to recover from cold stress , as well as other injuries . `` It 's an exceptionally bad year for the manatee , '' said Dr. David Murphy , the zoo 's veterinarian . So far this year , a record 280 or more manatees have died from cold stress-related illnesses . That 's estimated to be 5 percent of the total population in Florida . Add that to last year 's record mortality rate of 429 deaths from boat strikes and other causes , and that number may be as high as 10 percent . Marine biologist Andy Garrett says he 's never seen anything like this before . The full impact of the cold weather on the manatee population is still unclear , according to Garrett , who works for Florida 's Fish and Wildlife Conservation Commission . He says that when water temperatures dip below 68 degrees Fahrenheit , these subtropical animals simply ca n't cope with the cold . Last month , Florida 's water temperatures dropped as low as the 40s . While manatees are round and plump like seals and other marine mammals , their fat is not designed to insulate them from the cold , Garrett said . West Indies manatees roam the warm waters of the Caribbean , and in the summer have been known to migrate as far north as the New Jersey , and as far west as Texas . But those wintering in Florida are at the marginal edge of their habitat , and are always susceptible to the cold . On the other side of Tampa Bay , manatees have found a practical solution : Hundreds gather in a canal warmed by water discharged from a Tampa Electric Co. power plant . There , they are able to escape the cold , floating in waters that stay around 78 degrees . The carcasses of manatees who were n't able to find a warm water refuge have been turning up daily . Most end up at the Florida Fish and Wildlife Conservation Commission 's necropsy lab in St. Petersburg . The lab has been busy in recent weeks , at times examining a dozen manatees a day . There , Dr. Martine de Wit and her staff determine cause of death . It 's normally the young manatees that are most stressed by cold weather , but this year , full-size adults are dying . `` That is a very bad sign , '' she said . The cold water shuts down their internal systems . Many were unable to eat ; others drowned because they were unable to breathe . Garrett and de Wit believe that this may just be the beginning . They fear that more manatees will die during the spring , unable to recover from the trauma of Florida 's deep freeze .
Cold has killed 5 percent of West Indies manatees spring , 280 in all . Wildlife official : Manatees ca n't cope when water is colder than around 78 degrees . Manatee are already endangered , and spring known deaths were a record 429 . Necropsy lab official says she fears more may die in 2009 from lingering effects of cold .