Heat may push fish species south

distribution shifts further south to where temperatures are more suitable to the physiological preferences of each species,” Parsons said.

A severe marine heatwave in 2017/18 led to reductions in mussel and kelp beds, and tropical fish drifting into normally colder climes.

Marine heatwaves are likely to become longer and hotter in the coming decades, Niwa has warned.

Niwa ocean modeller Dr Erik Behrens said in March the idea of marine heatwaves becoming permanent was worrying.

“The impacts of climate change are happening all around us and New Zealand isn’t immune,” he said.

“We’re just coming off the back of one of our most intense marine heatwaves, like what we experienced in 2017. Our work indicates that this will start to become the norm as time goes on.”