Yes, they should be but depends on weather. Bad weather means more at park.
Most of them swim. They don't really have the knees to run. But in my experience (10+ years) they are seldom there in March. Especially if the weather has been warm. Cold air and warm water is what attracts them to this location. Lots in January. I kayak the river so I know when they are there. Last couple of March's I haven't seen any. Plenty in January when I was there. Good luck.
Yes. The park water system pumps warm water out so manatees are there almost all year around
It will depend on the weather. If you visit the website it will tell you the temp of the water and if the manatees are there at the park.
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