National Resources

Changes in Queensland's marine ecosystems

Laura Purcell.

Ocean ecosystems are changing and some fish are on the move along the Queensland coast.

Queensland's Coral trout, Plectropomus leopardus, may be one of many species feeling the heat. Photo: Richard Ling, Creative Commons (

With a coastline 9800km long, Queensland’s marine waters contain an abundance of marine life. Tropical islands, coral reefs, mangroves, sea-grass beds, rock pools and beaches provide a rich habitat of food and shelter for 1500 species of fish as well as marine turtles, marine algae, soft coral, sea pens, prawns, whale sharks and dugongs. Some important habitats for the marine creatures to thrive include the world’s largest reef complex, the Great Barrier Reef with its colourful and diverse species of corals; the Torres Strait, separating Cape York and Papua New Guinea, with its islets, reefs and coral cays; and the area between southern Queensland and Lord Howe Island (NSW) known as a biodiversity ‘hotspot’ for large pelagic fishes.

There are particular regions which are at risk from a loss of biodiversity and/or decline in key species due to changes in the climate. Referred to as the rainforests of the sea, coral reefs worldwide are sensitive to climate change and ocean acidification. These changes will make it more difficult for the reef to provide proper shelter and food for the many species which have come to rely on it. Corals may become vulnerable to more frequent bleaching events and coral disease leading to a loss of biodiversity and widespread changes in the composition of coral reef fish communities. It has been noted that coral bleaching has affected fish community structure at several locations on the Great Barrier Reef.

For tropical marine species it is most likely that the effects of climate change will allow them to migrate southward. For species which are eurythermal, meaning able to cope with a wide range of temperatures, they may be able to continue living comfortably without the need to migrate, such as the blue sprat Spratelloides robustus, sandy sprat Hyperlophus vittatus and anchovy.  Sharks and rays that live on the reef are considered to be most vulnerable to the effects of changes in water temperature, freshwater input and oceanic circulation. 

Venomous jellyfish and stingers may also extend their range southward towards cooler waters. Marine turtle populations are likely to be affected by the increase of temperature on the coast where they lay their eggs and coastal flooding from storm surges. The nest temperature plays a crucial role in how many females and males hatch. If the temperatures are high, then more females are produced. The offshore coral cay islands have white sand beaches, which means the environment may be a little cooler and more suitable for male production.

Read more about Queensland’s changing ecosystem, in response to climate change:

Marine Climate Change in Australia, Impacts and Adaptation responses, 2012 Report Card:

Queensland’s biodiversity under climate change: impacts and adaptation - synthesis report, 2012:

Great Barrier Reef Marine Park Authority:

Sea for Yourself:

About the Author

Laura Purcell is Communications and Publicity Officer for the Marine Adaptation Network (Adaptation Research Network for marine Biodiversity & Resources)

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