My wife Becky and I spent a week in Cairns, Australia during the mid-November of 2012.  While there, we snorkeled  the Great Barrier Reef by booking a boat tour to the Low Islets, near Cairns. Low Islets is a group of two small sand cay islands 13 km northeast off of Port Douglas, in the northern Great Barrier Reef.

     The Low Isles comprise a four acre coral cay surrounded by 55 acres of reef. The reefs are very close to the island, which makes snorkelling an easy and enjoyable experience.

Pictured above, the two small islands are separate but share the common reef.  Since Becky and I are avid snorkelers, we are taking advantage of this opportunity.

     The larger of the two Low Islets, Woody Island, is uninhabited except for a large bird population. It is a vital habitat for many species.  The smaller of the Low Isles, and the one we visited, is a coral cay with a lighthouse that has been operating since 1878. Weather data has been gathered from the island since 1887, and scientific associations date back to 1928 when it was the base for a year-long scientific survey that examined the structure and ecology of the surrounding reef. This was the first scientific study of a coral reef anywhere in the world, and many current theories of coral reef ecology are based on the findings of this expedition.  The 18 m tower was originally constructed on a timber frame with a galvanised sheath in the typical Queensland fashion, however Low Isles was the first to have porthole windows.

     This idyllic coral cay is one of 300 that are created when the low-lying flat reef is above sea level.  The main islet’s area is just 570 acres and is sheltered from the powerful southeastern swell that breaks in violently on the outer ribbon reefs.   

     Low Isle, (which has the heritage-listed lighthouse), began life as a lagoonal reef in which the central depression has been filled with coral debris to become a low-tide platform.  The corals of the islets are exposed by the tides.  Abundant coral fish species are bet wiewed by snorkeling; however, the crown of thorns starfish, coral bleaching, cyclones and climate-change have caused declines in all families of hard corals. Named by Captain Cook in 1770, these cays were the site of the first extensive scientific study of a coral reef anywhere in the world in 1928.

     The lslets are among thousands of individual reefs that sweep north from the Tropic of Capricorn, some 2,300 km to Torres Strait, where they merge with those along southern Papua New Guinea.  All modern reefs have evolved in  the last 6,000 years, since the sea level returned to the present level.

     There are 150 different species of hard corals in the waters surrounding Low Isles, although these are dominated by 15 species of soft corals. Looking closely, we saw the feathery tentacles of soft corals collecting tiny food particles from the water around them. Living amongst the corals was a large variety of fish, molluscs, sea cucumbers and other animals. Colourful blue, green and purple parrotfish were a common sight as well as angelfish, damselfish, anenomefish or clownfish, trevally, rabbitfish, sweetlip, moon wrasse, Man-of-War Jelly-fish, Box Jelly-fish and fusilleers, just to name a few! Plus, we ran into the resident turtles.