© CorbisLow temperatures can lead to "cold stress" in manatees, which can weaken and eventually kill the aquatic mammals.
Near-record numbers of manatees have died in Florida waters in early 2011, the second straight year of above-average deaths, alarming officials who are also puzzled by a surge in dolphin fatalities along the Gulf Coast.
Of the 163 manatee deaths recorded from Jan. to Feb. 25, 91 of them have been blamed on cold water temperatures off the southern state, where normally temperate weather draws the protected sea creatures during winter months, according to the Florida Fish and Wildlife Conservation Commission.
Manatees live near the coastline, and when weather turns cold they often shelter near springs or in warmer discharge canals at power plants to avoid the condition known as "cold stress," which can weaken and eventually kill the aquatic mammals.
A record 185 manatees died in Florida during the same period last year, according to the commission.
Authorities at the National Oceanic and Atmospheric Administration are also investigating the huge increase in baby dolphins found washed up dead along the US Gulf Coast, in the first birthing season since the BP oil spill disaster.
Eighty-three bottle-nosed dolphins, more than half of them newborns, were found dead in January and February along the coasts of Texas, Louisiana, Mississippi, Alabama and Florida, where millions of barrels of oil from a leaking undersea well poured into the Gulf of Mexico over three months.
