Under the Coral Sea

remote, rare and remarkable

“The ocean floor is the Earth’s last great frontier, full of great mountain ranges and deep

chasms that are largely unexplored.”Dr Robin Beaman,

marine geologist, James Cook University

Image: Little squid Abraliopsis Photographer: Jerome Mallefet

Image: Baby lizard fish Photographer: Asher Flatt Image: Dr Robin Beaman, James Cook University

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Only a tiny fraction of the Coral Sea Marine Park — the very highest peaks of its submerged mountain ranges — is visible to us. Testing the limits of our ability to explore, its deepest seamounts, plains and canyons and the ecosystems that populate them are fascinating and mysterious.

Did you know?

4060 m above the sea floor

Fraser Seamount in the south of the marine park rises

nearly twice as high as Mt Kosciusko,

Australia’s highest mountain.

65 million to 145 million years ago

the Gondwana supercontinent

fragmented, creating the terrain of the Coral Sea floor.

230 km long, 10 km wide and cutting 300 m deep

into the sea floorBligh Canyon is the largest

in the Coral Sea.

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Coral Sea Marine Park

Corals, algae and others living in the shallows above 60 m get their energy from the sun. Between 60 m and 140 m, filter-feeding octocorals rely on food sources carried by currents. The corals and other creatures living on the sea floor itself consume mostly plankton.

Recent researchIn 2012, the RV Southern Surveyor explored the Tasmantid seamount chain, collecting rock samples to date the volcanoes and when they erupted. Since 2006, a team from James Cook University and the University of Sydney have been mapping the Coral Sea Marine Park in detail using sonar technology.The JCU and USydney team, along with Geoscience Australia, have mapped numerous submarine canyons along the margin between the Coral Sea and the much shallower Great Barrier Reef. These are likely to be important biodiversity hotspots, but there is still much more to learn about them.

Learn moreAbout the Coral Sea Marine Park: About the depths of the Coral Sea: deepreef.org About visiting the Coral Sea: tropicalnorthqueensland.org.au

The Coral Sea Marine Park is managed by Parks Australia.

The deep unknown

home to extraordinary creatures

The Coral Sea floor consists of a series of deep basins rising to three large plateaus (Queensland, Marion and Eastern) and scored by numerous steep canyons.

Dramatic landformsThe deepest part of the landscape, the Coral Sea Basin, is underlain by oceanic crust formed around 61 million to 52 million years ago, after the Cretaceous period. On the plateaus, ancient reefs have become limestone and carbonate platforms that now support living reefs and cays.The islands of the Coral Sea lie on reefs capping its highest seamounts. Some seamounts have volcanic origins, whileothers are made from upturned blocks of buried continental crust. Many other drowned reefs lie below the surface.Extending along the east of the marine park is the Tasmantid chain of seamounts, extinct volcanoes formed roughly 40 million to 6 million years ago above a mantle hotspot, similar to the Hawaiian Islands.

Seamount ecosystemsThe seamount ecosystems are hotspots of biodiversity, abundance and biomass and may be important sites of evolution. Scientists have found little overlap between the species living on the different seamounts — each is its own little world.

GRAPHIC BY SOUTH WIND

Approx. distance from coast near Cairns (km)0 100 200 300 400 500 600 700 800 900 1000 1100 1200

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Coral Sea Marine Park

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Sunlit zone (0 ~ 200 m)

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Herald Cays Coringa Islets, Magdalaine Cays Lihou Reef Mellish Reef

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J2800 - PAR169.0516_Under the Coral Sea_may19-updated.pdf 2 14/05/2019 1:35:15 PM