We took the Shark Valley tram tour both during the day and returned for the sunset one also. Both were well worth it with good guides. Steve Bing led the daytime one and was a treasure of information. He had a great personality and sense of humor. He made us very aware of the delicate ecological balance that had been destroyed by man in the Everglades and referred to it as a dying swamp. During the summer he is in Yellowstone Park district in the "Tower" area and invited us to look him up there in the more wild area of the park and have a guided tour.
Early on, he got off of the front of the first tram car from which he was delivering his lecture and strode out into the shallow standing water of the "50 mile wide river" which the Everglades are and picked up some slimy yellowish muck that looked a bit like a sponge. It was Parafiten, an algae that allows saw grass two grow which decays and then allows other plant to grow including the all important Mangroves. Parafiten provides oxygen and a place for fish to lay eggs. The Mangrove trees are able to live in brackish water because their roots filter out the salt in salt water. Their leaves drop off, decay and provide food for other bacteria and plants which encourage fish.
Steve also suggested we visit Big Cypress Bend park 8 miles west of route 29 on US-41 outside of the Everglades park proper. It has huge old Cypress tress with lots of birds and animals.