Tropical fish appearing as far south as Tasmania

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The warming ocean is significantly changing Australia's marine ecosystems, with tropical fish appearing as far south as Tasmania and the feeding habits of seabirds changing in the Southern Ocean.

The developments have been charted in the latest report card on marine climate change in Australia, produced by federal science agency CSIRO and other research bodies.

The last report card was issued three years ago. Since then, the changes affecting the continent's waters had become more apparent, the report said.

Scientists analysed changes in sea temperature and levels, the east Australian and Leeuwin currents and the El Nino southern oscillation.

They found impacts on coral reefs, tropical, temperate and pelagic fish, marine mammals and reptiles, seabirds, mangroves, tidal wetlands and marine microbes.

The report card said warming sea temperatures were influencing the distribution of marine plants and animals, with species normally found in tropical and temperate waters likely to move south.

Researchers have reported finding tropical fish near Tasmania.

The report card said new research also suggested that winds over the Southern Ocean and present dynamics were strongly influencing the foraging of seabirds that bred in southeast Australia and fed close to the Antarctic in summer.

It said that some tropical fish species were better able to acclimatise to rising water temperatures than previously thought, although climate change was causing a decline in some temperate fish stocks.

Ocean acidification was also beginning to affect shellfish.