There are several different areas catering to different marine animals in Shark Bay. You can see the Inter-Tidal Zone at the front of this shot which flows into the Reef Lagoon. Beyond the bridge is the Shark Lagoon.
The bridge separating the two lagoons extends below the water level with large transparent acrylic panels. This gives snorklers and divers in the Reef Lagoon the ability to safely interact with the dangerous sharks.