Chapter II — Species of Special Concern 



August 1998. Its purpose was to identify questions 

 and research needs that should be addressed in order 

 to make informed management decisions on warm- 

 water refuges. Meeting participants reviewed results 

 of the study to assess effects of eliminating the warm- 

 water refuge in northeastern Florida late in 1997. An 

 unusually large proportion of tagged manatees in 

 northeast Florida died during the winter of 1997-1998 

 for reasons thought to be related to elimination of the 

 warm-water refuge. Although a few animals moved 

 south to power plant outfalls along the east central 

 coast of Florida in Brevard County, most did not and 

 attempted to use a small warm-water refuge at a paper 

 mill in southern Georgia. Perhaps 10 to 20 animals 

 were present in northeastern Florida and southern 

 Georgia during the winter of 1997-1998. 



The study also suggested that the increasing 

 number of manatees wintering at artificial refuges in 

 northeastern Florida and Georgia reflected a tendency 

 of some manatees that range northward in summer to 

 interrupt or halt their southward movement in early 

 winter. Because of the risk of cold-related deaths in 

 northern Florida and Georgia, meeting participants 

 agreed it was important to discourage such behavior 

 by means such as fencing off outfall areas to exclude 

 manatees or altering the discharges. Participants 

 agreed that such steps should be taken to prevent 

 manatees from remaining at artificial refuges north of 

 Brevard County, located midway along Florida's east 

 coast. It was agreed that similar steps also should be 

 taken for artificial refuges north of Crystal River on 

 the west coast. 



It was less clear what measures would be appropri- 

 ate for areas south of Brevard County and Crystal 

 River. Large and increasing numbers of manatees 

 have been wintering at artificial refiiges in Tampa Bay 

 on Florida's west coast and particularly in Brevard 

 County on the east coast where a winter count at 

 outfalls from two power plants exceeded 600 manatees 

 in 1997. These areas now constitute an important part 

 of the species' core winter range even though they are 

 more than 100 miles north of the historic winter 

 range. Meeting participants reached no consensus on 

 whether or what steps should be taken to limit or 

 encourage manatee use of artificial refuges between 

 these areas and the species' presumed historic winter 

 range to the south. There was general agreement. 



however, that steps to improve access to natural 

 warm-water springs within this area should be consid- 

 ered. Some springs that might otherwise be used by 

 manatees are not used or are used infrequently be- 

 cause spring runs are too shallow or are blocked. 



With regard to future plans, it was agreed that a 

 forum or technical workshop to review issues related 

 to the management of warm-water refuges should be 

 held during the summer of 1999. Co-conveners 

 would include the Service, the Sirenia Project, the 

 Florida Department of Environmental Protection, and 

 perhaps the Florida Power Commission. Participants 

 also identified a series of information needs to be 

 summarized or developed for the meeting. These 

 include summarizing recent and historic data on 

 seasonal water temperatures in key areas of Florida 

 and the location of natural springs, the history of 

 artificial thermal discharges in Florida and Georgia 

 and data on their effluent temperatures, cold-related 

 manatee mortality, past and current winter distribution 

 patterns of manatees, manatee movements in relation 

 to warm-water refuges, and thermal tolerances of 

 manatees. With regard to governmental and industry 

 actions to protect manatees, participants identified a 

 need for a review of planning and regulatory actions 

 related to thermal outfalls, a risk assessment regarding 

 manatee use of power plant outfalls, and a feasibility 

 study regarding the availability and cost effectiveness 

 of technology to develop non-industry-dependent 

 thermal refuges. 



In light of discussions at the meeting, the Service 

 did not convene a forum with industry and agency 

 officials in 1998. Instead, at the end of 1998, it had 

 begun efforts to organize a technical workshop on 

 future planning for both natural and artificial warm- 

 water refuges to be convened in the summer of 1999. 

 As discussed below, there were also related develop- 

 ments with regard to power plant outfalls at Fort 

 Pierce, in Brevard County, and in Fort Myers. 



Fort Pierce Power Plant — In 1996 a manatee 

 education and viewing center opened adjacent to an 

 artificial warm-water refuge formed by intermittent 

 thermal discharges from a power plant in Fort Pierce 

 about two-thirds of the way down the Florida peninsu- 

 la on the east coast. Maximum winter counts of up to 

 99 manatees have been recorded at the site. To 



99 



