Coral reef islands and atolls. The reef face is the zone above the reef floor or the reef drop-off. This zone is often the reef's most diverse area. Coral and calcareous algae provide complex habitats and areas that offer protection, such as cracks and crevices. Invertebrates and epiphytic algae provide much of the food for other organisms. A common feature on this forereef zone is spur and groove formations that serve to transport sediment downslope. The reef flat is the sandy-bottomed flat, which can be behind the main reef, containing chunks of coral. This zone may border a lagoon and serve as
Reef HQ HQ opened new 'Exploring our Wetlands' interactive kiosks developed by the Great Barrier Reef Marine Park Authority. Reef HQ Aquarium is located in the same complex as the Museum of Tropical Queensland and the Townsville Aboriginal and Torres Strait Islander Cultural Centre and an IMAX theatre in the Central Business District. Over 110 000 visitors tour Reef HQ Aquarium every year. Water motion is created in the Coral Reef Exhibit by a pneumatic wave machine. Unusually, the aquarium is open to the weather, receiving precipitation, sun- and moonlight, just like natural coral reefs. The tank holds approximately 2.5 million litres