Australian Marine Organisms Move South as Sea Temperatures Rise

CSIRO issues 2012 Marine Climate Change in Australia Report Card

Written by
John Virata

Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) has issued its 2012 Marine Climate Change in Australia Report Card, and the news isn’t too promising as scientists have studied changes in sea temperature, sea level, the East Australian Current, the Leeuwin Current and the El Niño-Southern Oscillation and have determined that climate change has affected the lives of many marine organisms in Australian waters. In its report, CSIRO states that the warming of the oceans and seas around Australia is causing the country’s marine plants and animals to move south.

Some findings in the report states that macroalgae in southern Australia have retreated approximately 10-50 kilometers per decade south on both sides of the continent. This, the report says will adversely affect entire marine ecosystems as macroalgae are a foundation species that are relied upon for the success of the ecosystem in which it inhabits.

As waters warm and species move south, other species are affected. On Australia’s Great Barrier Reef, the rise in sea temperatures have had a direct correlation with a reduction in chick growth in seabirds as well as the capability of these birds to successfully find food, a marked change in the sex ratio of sea turtles, higher incidence of coral bleaching, a decrease in the number of coral-dependent fishes, and an increase in the number of large herbivorous fish.

The report card cites south-east Australia as a global warming hotspot, with the scientists documenting a southward range increase for seaweeds, phytoplankton and zooplankton. Demersal and pelagic fishes have also been documenting moving south, and there has been a decline in rock lobster recruitment in these areas as well.

More than 80 Australian marine scientists representing 34 universities contributed to the report card. The report card details what is currently happening with Australia’s oceans and marine ecosystems, what could happen in the future, and what actions need to be taken to prepare and adapt to the changes.

For a complete look at the 2012 Marine Climate Change Report Card, please visit


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Fish · Lifestyle