Dave Allen

Warming seas will make life much harder for pāua, a NIWA study has found. Scientists raised young pāua in seawater of various temperatures and pH levels, then monitored their growth.

“Essentially, seawater of the future will be warmer, with lower pH levels,” said Vonda Cummings, pictured, who led the study. “We found that the outer layer of pāua shells gets etched by seawater with lower pH, especially if the water was warmer.” The pāua were sensitive to temperature variations as small as 2ºC, “and that will affect the thickness of pāua shells, which could mean they are not as resistant to waves and predators”.