Australia’s Great Barrier Reef supports about 1,625 fish species, around 450 types of hard coral and six of the world’s seven marine turtle species. Snorkellers can look for parrotfish, anemonefish and turtles on shallow reefs. Seagrass meadows support dugongs, coral cays provide nesting habitat, and offshore waters are home to rays, sharks and seasonal whales.
Jump to: Species to look for · Reef ecology and threatened species · Where to see wildlife · Identification and conservation
Species to look for
How many species live on the Great Barrier Reef? The Reef Authority records about 630 species of echinoderms, over 1,300 crustaceans, 14 types of sea snakes, more than 100 species of jellyfish and more than 30 species of whales and dolphins. These are estimates by group. They describe species richness across the region and give no census of individual animals. Discoveries and changes in classification can alter totals. Reef Authority biodiversity figures
Reef fish. Look for butterflyfish picking food from coral, damselfish sheltering among branches and parrotfish scraping surfaces with fused, beak-like teeth. The eastern clown anemonefish is orange with three white bars. The Barrier Reef anemonefish is orange-brown with two pale bars and a pale tail. Both live with host anemones. Eastern clown anemonefish · Barrier Reef anemonefish
Groupers, cod and wrasses. Potato cod, Queensland groper and coral trout belong to the grouper family. Potato cod have large dark blotches. Coral trout often have small blue spots. Wrasses include the large humphead or Maori wrasse and the slender bluestreak cleaner wrasse, which picks parasites from visiting fish at cleaning stations. Reef Authority animal guide · Reef biodiversity facts
Sharks and rays. Blacktip and whitetip reef sharks are examples of reef-associated sharks. The epaulette shark uses its paired fins to move across shallow reef flats. Reef manta rays filter plankton, while bottom-dwelling stingrays such as the bluespotted maskray forage on or in sand. Look for rays in sandy channels without approaching or stepping near them. Reef Authority animal guide · Lady Elliot Island manta rays
Marine turtles. The six species are green, hawksbill, loggerhead, flatback, olive ridley and leatherback. Adult green turtles graze mainly on seagrass and algae. Hawksbills often feed on sponges, loggerheads use strong jaws to crush hard prey, and leatherbacks specialise in soft-bodied prey such as jellyfish. Flatbacks feed mainly in shallow coastal waters and all known breeding sites are in Australia. Australian marine turtle profiles · Flatback turtle
Marine mammals. Bottlenose dolphins may be seen offshore, while Australian snubfin dolphins favour shallow coastal and estuarine waters. Dugongs graze seagrass and may leave feeding trails where they remove whole plants. Humpbacks migrate along Queensland’s coast and dwarf minke whales visit parts of the northern Reef seasonally. Reef Authority animal guide · Ribbon Reefs and minke season
Corals, jellyfish and sea anemones. Staghorn and table corals are growth forms seen in hard corals such as Acropora. Individual polyps build calcium carbonate skeletons that form the reef’s structure. Soft corals include flexible forms such as sea fans. Jellyfish and anemones also belong to the cnidarian group and use specialised stinging cells. Box jellyfish and the small jellyfish associated with Irukandji syndrome are the main marine stingers of concern to visitors. Reef Authority animal guide · Surf Life Saving Queensland marine stingers
Octopuses, clams, crabs and sea stars. Octopuses and cuttlefish can change their appearance to blend into their surroundings. Giant clams filter feed and also gain energy from algae in their tissues. Coral crabs shelter within branches, and hermit crabs reuse empty shells. Echinoderms include blue sea stars, crown-of-thorns starfish, sea cucumbers and urchins. Reef Authority animal guide
Seahorses, pipefish and new discoveries. Seahorses and true pipefish belong to the same family. Their small size and camouflage make many hard to spot. In 2026 researchers described a shaggy ghost pipefish, Solenostomus snuffleupagus, from specimens collected on reefs in Queensland’s Coral Sea. The fish is associated with red algae and is recorded elsewhere in the south-west Pacific. 2026 species description
Plants and algae. Seagrasses such as Halophila are flowering plants. Their beds provide food for grazers and shelter for juvenile animals. Mangroves such as the red mangrove grow along sheltered coasts and estuaries, where submerged roots create habitat. Algae range from microscopic coral symbionts to seaweeds such as Halimeda, a green alga whose calcium-rich segments contribute to reef sediment. Reef Authority biodiversity guide
Reef ecology and threatened species
How wildlife keeps the reef functioning
Habitat builders. Reef-building corals create the ledges, holes and branches that provide shelter at many scales. A branching coral can shelter small fish, crabs and shrimp, while a large coral bommie creates feeding and refuge areas for larger fish.
Grazers and cleaners. Parrotfish and some surgeonfish limit algal growth on reef surfaces, helping keep space available for young corals. Some parrotfish also produce sand as they grind and pass carbonate material. Cleaner wrasses reduce parasite loads by picking parasites from fish that visit their stations. Reef Authority biodiversity facts
The reef food web. Algae and phytoplankton capture energy from sunlight. Zooplankton eat some of those producers and become food for small fish and filter feeders. Coral trout and other predators eat smaller animals. Sea cucumbers process organic matter in sediment, while bacteria and other decomposers recycle nutrients. These pathways overlap, so reef wildlife forms a food web with multiple routes.
Native species and introduced pests. Crown-of-thorns starfish naturally eat live coral. Outbreaks can remove large amounts of coral cover and prompt targeted control on priority reefs. Introduced goats and weeds can damage island vegetation and nesting habitat. Vessel biofouling can also spread marine pests, making clean hulls and gear important. Reef Authority biodiversity guide · Crown-of-thorns control
Threatened, rare and endemic species
Threatened wildlife. Australian national listings include endangered loggerhead, olive ridley and leatherback turtles and vulnerable green, hawksbill and flatback turtles. Bycatch, vessel strikes, debris, warming nesting beaches and habitat loss can affect turtles in different places and life stages. Use the national list for legal status and consult current species profiles when comparing it with global assessments. Australian marine species assessment
A local name can cover a wide range. The Barrier Reef anemonefish is native to the Reef and also occurs elsewhere in the south-west Pacific. Anemonefish distribution
Rare on a tour can mean hard to see. Dugongs spend time feeding in shallow seagrass meadows, often away from outer-reef snorkel routes. A small octopus or pipefish can be hard to find even at an occupied site. Choose a trip for habitat and conditions, then treat sightings as a bonus.
Where to see wildlife
Cairns and Port Douglas. Outer-reef coral gardens and walls offer good opportunities for reef fish, clams and sometimes turtles or reef sharks. Nearshore trips to Green Island or Low Isles cover different habitats, including shallow coral and seagrass around the cays. Ask which habitat the operator plans to visit. Great Barrier Reef snorkelling guide · Great Barrier Reef scuba diving guide
Northern Ribbon Reefs. Cod Hole is known for potato cod. June and July offer a chance to encounter dwarf minke whales on authorised trips. Raine Island and nearby cays are important green turtle nesting sites. Raine Island is culturally significant to Wuthathi and Meriam Nation Traditional Owners and is closed to public access. Ribbon Reefs · Queensland Parks Raine Island
Southern Reef and Bundaberg. Lady Elliot Island has reef manta rays throughout the year, with more sightings generally in winter. Heron Island and nearby cays support nesting turtles, and Mon Repos offers guided viewing from the mainland near Bundaberg during the nesting and hatching season. Check dates and book controlled-access turtle experiences in advance. Lady Elliot seasonal wildlife · Queensland turtle viewing guide
| Time | What it means for wildlife trips |
|---|---|
| April | A reasonable shoulder month for reef fish and turtle sightings in the water. In the north, rain and swell may linger after the wet season. Southern nesting and hatchling activity can be tapering, so confirm local viewing dates. |
| June–July | Possible dwarf minke whale encounters on northern Ribbon Reef itineraries. Winter also offers a stronger chance of manta rays around Lady Elliot Island. |
| Summer | Main nesting activity for many turtles at monitored beaches. Follow operator guidance on lights, access and distances, and allow for wet-season weather on northern trips. |
Identification and conservation
Pictures and identification. The Australian Museum has labelled photos and distribution maps, while Fishes of Australia lists scientific names, identification features and regional records. Photograph animals from a distance and record the location and habitat to help with identification. Australian Museum reef fish example · Fishes of Australia
Wildlife for kids. Try a drawing with three layers. Put plankton near the surface, add a clownfish in its anemone and draw a stingray over the sand. Have kids trace where each animal finds food or shelter. Wildlife of Australia’s Great Barrier Reef by Myke Mollard is an illustrated book with identification keys and examples ranging from molluscs to seabirds and marine mammals. Children’s Book Council of Australia
Conservation and reporting. The Great Barrier Reef Foundation supports projects such as turtle habitat recovery and local reef restoration. WWF-Australia’s work includes efforts to reduce harmful fishing interactions with threatened wildlife. Visitors can contribute records to Eye on the Reef, while sick, injured or stranded wildlife should be reported through Queensland’s wildlife reporting channels. Great Barrier Reef Foundation · WWF-Australia’s Net-Free Reef campaign · Eye on the Reef Sightings Network · Reef Authority animal reporting
What is the most dangerous animal on the Great Barrier Reef?
Risk depends on where and when you enter the water. Box jellyfish and Irukandji are serious hazards in tropical waters, with higher risk generally from November to May. Estuarine crocodiles are a serious risk in some coastal and estuarine habitats. Stonefish, cone snails, sea snakes and blue-ringed octopuses are venomous. Follow local signs and crew advice, wear protective clothing when advised and leave marine life where it is. WorkSafe Queensland stinger guidance · Queensland diving and snorkelling code
What is killing the Great Barrier Reef?
Human-caused warming increases marine heat stress and the risk of mass bleaching. Cyclones, outbreaks of coral-eating crown-of-thorns starfish and poor water quality can add pressure. Different disturbances affect different reefs, and some corals recover between events. See the complete coral bleaching guide for observed losses and recovery. AIMS reef condition report
What wildlife lives in the Great Barrier Reef?
Coral gardens support fish, molluscs and other invertebrates. Seagrass meadows feed turtles and dugongs, mangroves shelter juvenile animals, and islands and cays host nesting seabirds and turtles. The wildlife you encounter depends on which of those habitats you visit. Reef Authority habitat and biodiversity guide