They are around - there was a lot of boat traffic nearby. That was in Silver Springs State Park near Ocala. I have seen them piled up tight other places. Myakka River State Park down near Sarasota has "a lot" but they are all around Florida waterways.

No. It is the Silver River at silver springs state park but relatively close. We actually saw a Manatee there - which seems weird for this time of year.

which Blue Springs ... ;-) there are 4 in Florida. It's crazy https://www.floridastateparks.org/search?keywords=blue I live near Madison Blue Springs.