AUSTRALIAN scientists say there is now "striking evidence" of extensive southward migration of tropical fish and declines in other species due to climate change, in a major ocean report card.
Compiled by more than 80 of Australia's leading marine experts for the government science body CSIRO, the snapshot of global warming's effects on the island continent's oceans warned of 'significant impacts'.
"Climate change is already happening; widespread physical changes include rapid warming of the southeast and increasing flow of the east Australia current," the report said.
"There is now striking evidence of extensive southward movements of tropical fish and plankton species in southeast Australia, declines in abundance of temperate species, and the first signs of the effect of ocean acidification on marine species with shells."
The report described southeast Australia as a 'global warming hotspot', with the contraction south and strengthening of southern hemisphere winds causing the eastern current to become more intense and also warmer.
"A range of species including plankton, fish and invertebrates are now found further south because of the enhanced transport of larvae and juveniles in the stronger current and the high rate of regional warming," it said.
Sea snakes were declining and warmer beaches were changing turtle breeding habits and seabird and marine mammal feeding and mating, it added.