Global Warming Science -


Manatees - Waiting For Global Warming


[last update: 2010/02/14]



Global warming alarmists pretend that warming will kill many animals, whereas cold is actually more devastating – especially to wildlife in Florida.

The EPA’s regulations under the Clean Water Act are also increasing the deaths of manatees.




The following article is from Feb 11, 2010. []





Manatee Area Sea Surface Temperatures


The following figures show the sea surface temperatures (SST) for the Florida manatee area. The graphs show the monthly SST anomalies (blue) and annual average SST anomalies (red) for 1930 through 2008 (data from the CRU HadSST2 database plotted at The HadSST2 database is averaged over 5x5 degree grids – the temperatures for the 4 grids encompassing the manatee area are shown.


The grid covering most of Florida’s coastline (25-30Nx80-85W) shows a slight cooling trend over the last 80 years. The other grids show a slight warming trend which does not exceed the warming of the 1930s.


The Gulf Coast Side of Florida




The Gulf Stream Side of Florida





Environmentalist Propaganda


Of course reality doesn’t affect environmental groups’ propaganda. For example, the “Defenders of Wildlife” states: “Since manatees spend their live in the water, global warming poses significant threats to their well-being. Higher water temperatures along the Gulf Coast has lead to an increase in toxic algae blooms, such as the red tide that killed more than 150 manatees in 1996.” []


The following figure shows the sea surface temperature anomalies for the 5x5 degree grid covering Florida’s Gulf Coast for 1970 – 2008 (monthly data – blue, annual average – red). A distinct cooling trend contradicts the “Defenders” propaganda.




The 1996 mortality episode referred to by the “Defenders” is described by the “Save the Manatee Club” as: “The red tide epizootic began on March 5 and continued through April 28 along Florida's southwest coast, wiping out approximately 15% of the known west coast population of manatees. … In 1982, another outbreak of red tide was believed to have contributed to the death of 37 manatees. Over the years however, red tide manatee mortality events have been rare. Red tide is considered to be a natural event” []


The following figure shows the same data as above for 1990 – 2000. The 12 months of 1996 are highlighted by the pink box, while the March – April red tide episode is highlighted by the green box.




According to the Fish and Wildlife Research Institute, salinity was the factor, not temperature: “Red tides do not usually appear inshore during the winter/spring months when manatees are congregated in low- or zero-salinity areas in the warmer waters of the coastal power plants, at warm water spring refugia, or in residential canals. Unusually, in the winter/spring of 1982 and 1996, red tide encroached inside the barrier islands of southwest Florida. High-salinity areas (above 24 ppt) allowed persistently high concentrations of K. brevis [red tide] cells to be maintained.” []


Environmentalists don’t let actual data get in the way of their propaganda, however.




Fossil Fuel Fired Power Plants Keep Manatees Warm in Winter


AGW alarmists would like to shut down all power plants, yet “An offline Florida power plant is providing a warm-water refuge for several hundred manatees who like the Sunshine State's human residents are shivering in record low cold temperatures. … The oil- and gas-fired plant was taken off line last year for modernization but [Florida Power and Light] FPL has installed a special heating system to keep waters at an attractively balmy temperature for the manatees” []

The LA Times showed the following picture of manatees using the warm water output from a power plant to survive. “More than 200 manatees are wintering in a balmy canal outside a power plant, the latest exotic Florida animals seeking refuge from the state's frigid temperatures. Giant eagle rays and spinner sharks joined them in the 70-degree waters Thursday as onlookers watched them frolic near Apollo Beach. With temperatures up to 20 degrees below normal, some less resourceful animals needed help from humans to survive.” []



A study of Florida’s manatees and power plants (“Laist and Reynolds “Florida Manatees, Warm-Water Refuges and an Uncertain Future”, 2005 []) states: “Most Florida manatees depend on localized warm-water refuges in the southern two-thirds of Florida to survive winter; about 60% use outfalls from 10 power plants. Future availability of these refuges is in doubt; most of these power plants may be retired within the next 20 year … plant retirements may increase cold-stress-related deaths and significantly decrease manatee abundance. … All power plant outfalls now used by manatees were built between the 1940s and early 1970s. Many of these plants have reached or are approaching the end of their planned operational lives and soon may be retired. Since they were built, regulations under the U.S. Clean Water Act have prohibited new facilities from discharging effluent substantially warmer than the receiving waterbodies. The older, pre-existing plants, however, were granted variances allowing them to continue discharging warm water. Unless the older units are “repowered,” an expensive process of updating or replacing existing generating units with more efficient units, their retirement in the next 10 to 20 years will eliminate discharges on which most Florida manatees now depend for winter survival.


The following figure shows the location of the power plants that the manatees rely on for survival (from the above cited report).




The above report states: “As most power plants now used by manatees had not yet been built at that time [1950], some assume that, if power plants were closed, manatees would simply move south to warmer areas in Florida with no effect on overall manatee abundance. Such assumptions, however, may be overly simplistic and largely incorrect. Based on site-fidelity to winter refuges and manatee responses to past outfall shut-downs, it seems questionable, if not doubtful, that all or even many manatees would move to southernmost Florida or to natural springs that lie outside of their familiar range.


Perhaps the pro-AGW environmentalists will just claim that the manatees are an “invasive species” and should be allowed to succumb to the cold.