Sep 27, 2018

New Zealand waters seeing fastest rate of acidic change in 25 million years

by
Chloe Ranford
,
Stuff
A salmon farm in the Pelorus Sound. Greater acidity could stunt the growth of finfish larvae. Photo: Stuff
A salmon farm in the Pelorus Sound. Greater acidity could stunt the growth of finfish larvae. Photo: Stuff

New Zealand's waters are becoming more acidic as they continue to absorb about a quarter of our carbon dioxide emissions. 

The world's oceans are seeing their fastest rate of acidic change in 25 million years, with the rate of decline about to snowball if greenhouse gas emissions are not checked. 

Seawater pH levels have dropped from 8.2 to 8.1 since the 1870s. 

...

National Institute of Water and Atmospheric Research climate scientist Petra Pearce said coastal waters could be more susceptible to high acidification than offshore waters, due to onshore run off.

Greater acidity could stunt the growth of or create behavioural changes in finfish larvae, such as salmon, which could then lead to an increase in finfish death or a decrease in their production, Pearce said.

She also said it could impact the shells of paua, mussels and oysters, reducing their larval growth, and the shells of plankton, reducing their growth rates.