The coastal estuaries are flanked by shallow water seagrass habitats. Seagrasses are underwater flowering plants, and similarly to mangroves, they stabilise the seafloor preventing erosion. Seagrasses are also great sequesters of carbon. Seagrass beds are nursery grounds for juvenile fish and prawns, some of which play a vital role in our commercial fishing industries.
Highly productive seagrass beds provide food for several large marine species. For example, the Green Sea Turtle gains 97% of its food from foraging on lush seagrass and using this energy to migrate to many coral reef cays to breed and nest. The diverse habitats of the Great Barrier Reef provide important feeding and breeding grounds for vulnerable species.
Coral Reefs only represent 6% of the Great Barrier Reef Marine Park, but are some of the most diverse habitats on the planet. This high diversity is strengthened and supported from linkages to surrounding ecosystems. Fringing Reefs are the first reefs that you will reach, once you leave the coast behind. Most continental islands in the Great Barrier Reef are surrounded by coral. As we travel further from the coast you will discover patch reefs and ribbon reefs. Species composition varies across the continental shelf.
At the continental edge or where the furthest reefs from the coast are, the Great Barrier Reef meets the open ocean. At this interface, complex oceanographic processes occur, which push deep cold nutrient rich water up onto the continental shelf. These extra nutrients regularly fuel plankton communities that surround coral reefs and provide additional energy to individual coral reefs. This is also the areas where ocean giants like whale sharks and giant black marlin can be found. Giant Black Marlin aggregate off the reefs of Cairns every Spring to Spawn.