(First of all, let me say that this experience is not for everyone. If you are opposed to the idea of aquariums or zoos, then skip the lagoonarium because this is like one big HUGE outdoor aquarium or zoo.) However, we loved this experience - it was crazy fun, and super entertaining!
This is a family owned business - from what I gather, two brothers run the show (act as tour guides/clowns)... pick you up, show you around, explain everything. They are hilarious and funny, and full of energy. We were laughing non-stop. At one point the dad (?) came out in a loincloth made of a yellow pareo, with a big huge machete and tuna - went directly into the shark enclosure, chopped up the tuna, and fed all the sharks!
We did the 2-3 hour tour - they picked us up at our hotel, then took us (directly across the lagoon since we were in the hotel next door) to their privately owned motu. In front of their property, they have netting set up in the lagoon forming an outdoor aquarium. Most of their animals were raised in the lagoonarium, and are not "wild".
They gave us some snorkel gear and took us into the various enclosures where you can swim with the different creatures:
Enclosure #1: GIANT nurse shark named "sharkira".
Enclosure #2: Sea turtles (you don't actually get in the water with the turtles because apparently they bite - but you get close enough to feed them)
Enclosure #3: Tropical fish, black tipped reef sharks, and lemon sharks! Look underwater at the mouths of the sharks - these look like real sharks you see on TV - but they are mild and docile.
There is also some free time to swim/snorkel wherever you like, and near the end they serve fresh cut fruit and do a "pareo show" - the guides will ask for volunteers and show you different ways to tie sarong/pareos.