Three Sisters Springs Manatee Information

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Three Sisters Springs documents and important information.

DATE: November 21, 2017
Contact: Joyce Palmer 352-436-7156


Guidelines for Visitor In-water Access to the Three Sisters Springs Unit of the Crystal River National Wildlife Refuge for Manatee Season
November 15, 2017 to March 31, 2018

The refuge has updated the management plan for determining when the Three Sisters Springs should be open or closed to in-water public access. Our goal is to protect warm water habitat at Three Sisters Springs for federally threatened Florida manatees (Trichechus manatus latirostris) when they are most likely to use the warmer spring water to avoid exposure to debilitating cold periods. The U.S. Geological Survey (USGS) Sirenia Project has been tracking manatees in the CRNWR area with global positioning system (GPS) telemetry since 2006, and most of these animals have visited Three Sisters Springs multiple times to meet their thermoregulatory needs. 
Analysis of movements of tagged manatees combined with environmental information such as water temperature and level in the Gulf of Mexico, Crystal and Salt Rivers and local springs within the Kings Bay area provides valuable insight into their habitat use patterns relative to measurable ambient conditions. As expected, manatees were found in the springs more often when Gulf temperatures were relatively cold (i.e., less than 20 °C). However, a more detailed look at manatee GPS locations revealed that when Gulf water temperatures at Shell Island (Figure 1) were colder than 17 °C, manatee habitat use patterns shift from the Gulf to higher occurrences in Three Sisters Springs and the adjacent springs known as Idiot’s Delight. Thus, the Service will close Three Sisters Springs to human activity when Gulf temperatures at Shell Island drop to 17 °C and the springs will remain closed until temperatures rise above 17 °C for 24 hours or longer. Real time Gulf temperatures at Shell Island will be monitored regularly and are available at: (
The USGS Open-File Report used to determine visitor in-water access to the Three Sisters Springs is available for download at the link below. 

Fig 1 Proportion of manatee global positioning system


USGS: Timing of warm water refuge use in Crystal River National Wildlife Refuge by Manatees - results and insights from global positioning system telemetry data.