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Reef Sites We Visit

Our Reef Sites

The extensive network of Great Barrier Reef sites Reef Biosearch visit and care for spans over 100 km from Moore Reef east of Cairns to the Agincourt ribbon reefs north of Port Douglas.

Agincourt Ribbon Reefs The Agincourt Reef group consists of a number of distinctively separate reefs and include a cluster of five reefs within the Offshore Port Douglas Sector of the GBRMP. Located at the very outer edge of the Great Barrier Reef, special reefs known as ‘ribbons’ run parallel to Australia’s Continental Shelf.

Adjacent to the Coral Sea trench, these ribbon reefs are recognized as amongst the most pristine eco-systems in the reef’s environment. Being close to the continental shelf, the reefs are flushed by clear oceanic waters. Clear water provides the best possible underwater visibility, encourages rich coral growth and supports spectacular marine life.

The Agincourts are renowned for coral diversity and abundance of marine life. Coral distribution within the group is a reflection of the reef geomorphology and is a good representation of the different habitat types associated with reefs in the general area.

The Agincourt group of reefs are in the vicinity and of significance to the Wujal Wujal Aboriginal Community at Bloomfield.

Agincourt Reef 3 is the home of Quicksilver’s spacious activity platform permanently moored in the sheltered lagoon. Dive and snorkel catamarans Silversonic and Poseidon have permits to visit an incredible selection of 35 remote and exclusive World Heritage sites.

Visit Agincourt Reef with Quicksilver, Silversonic and Poseidon

Green Island
Green Island is a 6000 year old coral cay located within the Great Barrier Reef Marine Park. The island is 27 km (16 miles) from Cairns and sits on the north-western edge of the reef flat.
The reef surrounding Green Island supports a diverse range of habitats and marine life. There are two significant habitats:

  1. the seagrass beds in the shallows
  2. the reef that starts shallow and continues into the depths.

Seagrass beds support a wide range of animals, from juvenile fish that use the grass for protection from predators to a large sea turtle population and dugong that feed on the seagrass.

The reef around Green Island has over 190 different types of hard corals and over 100 types of soft corals.

With a circumference of just 1.6km, Green Island is home to over 120 species of plants, including a unique mixture of coastal and rainforest plants. The coastline is ringed by short, scrubby coastal vegetation that can survive drier conditions along the beach. But, step a few feet in to the centre of the island, and the vegetation changes abruptly to a dense, shady vine-thicket rainforest.

In fact, of the 300 coral cays on the Great Barrier Reef, Green Island is the only one with a rainforest. Coconut trees are not thought to be native to the island, but were introduced to the island in 1889 to provide food, drink and shelter for fishermen and stranded sailors.

Green Island attracts a wide range of birds, including land birds, seabirds and migratory birds that pass through the Great Barrier Reef on the way to nesting grounds. There are over 55 species of birds regularly seen on Green Island. Of these, 13 are seabirds and 38 are shore and land birds. About 15 types of birds regularly nest on the island.

Visit Green Island with Great Adventures and Green Island Resort

Moore Reef
Moore Reef is located about 50 km (26 nautical miles) east of Cairns and is the beautiful site of Great Adventures’ reef activity platform (pontoon). The platform is located on the north western end of Moore Reef and home to Wally, the friendly resident humphead Maori wrasse.

The Great Barrier Reef Marine Park Authority (GBRMPA) has identified Moore Reef as one of the most biologically diverse reefs in the Great Barrier Reef system.

The reef’s biodiversity is attributed to its location in the Coral Sea and its proximity to the continental shelf. This location provides a unique environment that supports a wide range of marine life. The reef’s biodiversity is also influenced by its depth.

The shallow waters surrounding the reef, in particular throughout the protected waters of the lagoon, are home to a variety of hard corals that form complex reef structures.

Visit Moore Reef with Great Adventures

Low Isles
Situated 15km north-east of Port Douglas Low Isles is a 4 acre coral cay surrounded by 55 acres of reef. The two small islands are separate with one common reef. The larger of the two, Woody Island, is uninhabited except for a large bird population. It is a vital habitat for many species.

There are about 150 different species of hard corals in the waters surrounding Low Isles, although these are dominated by 15 species of soft corals. If you look closely, the feathery tentacles of soft corals can often be seen collecting tiny food particles from the water around them. Living amongst the corals is a large variety of fish, molluscs, sea cucumbers and other animals. Colourful blue, green and purple parrotfish are a common sight as well as angelfish, damselfish, anenomefish or clownfish, trevally, rabbitfish, sweetlip, moon wrasse and fusiliers, just to name a few!

At least seven species of seagrasses grow on the intertidal sandflats of Low Isles, providing a home and food for such animals as green turtles, sea cucumbers, the attractive spidershell, as well as rays.

Some island history…

  • The Aboriginal people know these islands as Wungkun. It is an important Indigenous and cultural site for the KuKu Yalanji and Yiragandi people as the sea country for both groups overlaps at Low Isles.
  • In 1770 Captain James Cook described Low Isles as a “small low island” and was officially called Low Isles in 1819.
  • Weather data has been gathered from the island since 1887 and the historic lighthouse has been operating since 1878.
  • In 1928 it was the base for the first scientific study of a coral reef anywhere in the world, examining the structure and ecology of the surrounding reef. Many current theories of coral reef ecology are based on the findings of this early expedition.
  • Quicksilver commenced the first daily cruises to Low Isles in 1979 and in 2000, the Low Isles Heritage Walk was officially opened.

Visit Low Isles with Wavedancer

Michaelmas Cay A low lying vegetated sand cay encircled by a fringing reef, Michaelmas Cay is a National Park and a protected sanctuary for migratory seabirds. Michaelmas Reef is 43km north-east of Cairns and 17km north of Green Island. It covers an area of 1.8 hectares and rises to a height of 3.5m above sea level. The Cay is around 360m long x 50m wide.

The Cay is rich with a myriad of sea life including green sea turtles (which occasionally nest on the cay), molluscs and invertebrates of all kinds and hundreds of species of tropical reef fish including Humphead Maori Wrasse. The reef surrounding the Cay is especially renowned for its abundance of giant clams.

Michaelmas Cay is a major natural seabird habitat and one of the most important in the Southern Hemisphere. At least 23 species of seabirds have been recorded here. Many breeds find this island an ideal nesting habitat and is one of the most significant bird sanctuaries on the Great Barrier Reef. At the height of nesting and breeding season (during Summer months) up to 20,000 birds have been observed. To protect this environment, access to Michaelmas Cay is limited to the restricted area marked out by rope.

A bit of history..For a period during the late 1800s and early 1900s the island was used by sea cucumber pickers (Beche-de-mer) and for guano mining. In 1937 it was declared a fauna sanctuary and formally a national park in 1975.

The Cay has cultural significance to the local Gungandji, Mandingalbay-Yidinji and Yirriganydji indigenous peoples.

Visit Michaelmas Cay with Ocean Spirit

Flynn, Milln, Thetford & Pellowe Reefs
Silverswift and Pro Dive Cairns visit a selection of 19 exclusive sites over four of the best Outer Great Barrier Reef locations at Flynn, Pellowe, Milln and Thetford Reefs. These sites are chosen for their magnificent coral formations, varied marine life and underwater visibility.

They have superb bay-like dive and snorkel sites providing spectacular underwater sand dunes and remote steppingstone-like coral bommie systems. These sites are also renowned for their congregating schools of large pelagic fish.

Flynn Reef: Located approximately 55 km NE of Cairns, Flynn Reef is known for its extensive coral formations, including table corals and staghorn corals.  Giant clams, fan coral and staghorn thickets in the sand, and pelagics including trevally and Spanish mackerel can be seen. During summer months, leopard sharks and occasional whale shark sightings.
Pellowe Reef: A small isolated reef located close to the edge of the continental shelf is approximately 60 km NE of Cairns.  Pellowe Reef is a gem of the Outer Reef. Access to the reef is weather and tidal dependent. The reef drops away very quickly at places to 30 metres and stronger currents can be present as well. Being closer to the shelf, large pelagic fish can be sighted along with the more regular sightings of schools of chevron barracuda, numerous sea cucumbers and nudibranchs.
Milln Reef: Located approximately 54 km NE of Cairns, Milln Reef’s shallow lagoons and fringing reefs provide an excellent environment for exploring the diverse marine life. Sites are home to resident turtles and white tip reef sharks. At the Swimming Pools you can expect to see schools of diagonally banded sweetlips and nudibranchs to name a few.
Thetford Reef: Situated approximately 43 km NE of Cairns, Thetford Reef is a mid-shelf reef. This reef is home to many soft and hard corals like staghorn and plate coral and an abundance of marine life. Look for the giant clams, butterfly fish, damsels and angelfish. Access to the reef is very weather and tidal dependent.

Visit with Silverswift and Pro Dive Cairns