Manatee Movement Animation in Tampa Bay
Researchers at FWRI track manatees with state-of-the-art Global Positioning System (GPS) satellite-linked tags that collect and transmit data on individual movements, behavior and temperature. This two-minute animation dynamically displays the movements of a manatee called TTB099 in northeast Tampa Bay during a three-day period in winter. This adult male was 2.8 m (9.2 ft) long and weighed 399 kg (880 lb) when tagged in December. GPS locations were obtained at 20-minute intervals and the animation shows two hours of track line (i.e., 6 consecutive locations) at any one time. The symbol color depicts water temperature experienced by the manatee based on the tag temperature (see water temperature legend).
Manatees use the warm waters of the TECO Big Bend power plant’s discharge canal in Apollo Beach for shelter from the cold bay waters in winter. They seek this warmth because they are physiologically unable to survive exposure to cold water for extended periods. They journey out of the refuge into Tampa Bay to feed on shallow seagrass beds (green areas on map), and then return to the warm-water site. This pattern of commuting between essential habitats is called “central-place foraging”, the warm-water refuge being the central place from which feeding trips originate.
As you watch the animated movement track, note how the manatee experienced warm water (red symbols) in the discharge canal and then encountered cooler waters (blue-green-yellow symbols) out in the bay.
If you pay attention to the times at which TTB099 departed and returned to the warm-water refuge, you will notice that this individual was generally out on the seagrass flats at night and back in the warm-water canal during the day. That daily pattern of presence in the refuge and on the grass beds was shown by many other manatees as well.