Warm water coral moving south to Tasmania

Warm water corals are colonising Tasmanian reefs as climate change pushes up temperatures in the Bass Strait.

University of Tasmania scientists found the corals moved in after sea urchins ate out native kelp beds, leaving the reefs free of weed and ready for them to inhabit.

Marine biologist Scott Ling says the reef coral species from warmer waters were extending their range to northern and eastern Tasmania.

"In some cases (we're finding) wholesale changes in the reef ecosystems as sea life responds to rising temperatures," Dr Ling said.

The corals have followed invasive Long Spined Sea Urchins, also lured south by the rising sea temperatures.

Dr Ling said the sea urchins' devastation of eastern Tasmanian kelp beds was assisted by declines in the spiny creature's predators, such as lobsters.

"By grazing down kelp beds ... Long Spined urchins have removed one of the main competitors of hard corals," he said.

Seaweeds compete with coral for living space on reefs and the urchins have created room in the Bass Strait marine ecosystem for corals to expand into.

Dr Ling said this form of 'tropicalisation' of a temperate ecosystem was not restricted to Tasmania.

More coral growth is likely as sea surface temperatures rise and an increasing number of sea urchins move south.

He said kelp systems are under threat in many locations in Australia and globally as a result of climate change.

The research was published in the journal Coral Reefs.