The research, including by the National Institute of Water and Atmospheric Research (Niwa) and University of Otago scientists, shows that higher seawater temperatures and ocean acidification will affect the thickness of paua shells.
"It seems obvious that a healthy planet requires a healthy ocean," Prof Abby Smith, of the University of Otago, said yesterday.
"What we need to realise is that big, planet-wide changes can affect even very small shells living under a rock in New Zealand," Prof Smith, of the Otago marine science department, said.
The research team, which includes Niwa scientists Dr Vonda Cummings, Peter Marriott and Jane Halliday, as well as Prof Smith and recent Otago graduate Dr Bryce Peebles, has discovered the effects of warmer seawater and ocean acidification on young paua.
Dr Cummings said in the future seawater would be warmer and more acidic, and this would affect the thickness of paua shells, meaning they were not as resistant to waves and predators.
The scientists grew young paua - less than 24mm long - in seawater with different combinations of temperatures and pH levels and investigated aspects of the creatures' survival, growth and general health, as well as their shells' thickness, integrity and composition.
The study showed that juvenile paua were good at surviving and growing in warmer, more acidic water, but the outer layer of their shells was etched by seawater at lower pH, especially if the water was warmer, Dr Cummings said.
This etching reduced the level of protection for paua.
Prof Smith is trying to raise awareness about climate change and its "devastating" effect on the ocean, and organised a special marine-themed march, held alongside the recent School Strike 4 Climate march in Dunedin.
New Zealand exported both paua meat and shell and almost nothing was "so quintessentially New Zealand" as an artwork or jewellery made of paua shell.
"Ocean acidification could make shells thinner, or chemically different, or even impossible," she said.
Paua shell was unique - "no other abalone species is blue and as lovely. It's also endemic. The species only lives in New Zealand," she said.
The research has been published in PeerJ, a peer-reviewed international scientific journal.
