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Covering Climate Now: Concerns over effect warming seas will have on paua industry

This story is part of Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

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1 NEWS’ Kate Nicol-Williams has this report. Source: 1 NEWS

Commercial paua diving is a $50 million industry, according to Paua Industry Council scientist Dr Tom McGowan.

“We work with people who this is their livelihood and you know it’s their chosen way of living, so people see it very important as something to protect their resource,” he said.

That’s why divers and the council are concerned about the impact of warming oceans and ocean acidification from the absorption of carbon dioxide.

In 2013, the Intergovernmental Panel on Climate Change reported the ocean has soaked up 93 per cent of the excess heat from greenhouse gasses, slowing down global warming but having a negative effect on marine life and ocean waters.

“Most alarming thing I guess and we know this specifically in regards to paua is increasing acidity causes high mortality at the larval stage,” Dr McGowan said.

“The amount of carbonate in the water is also decreasing and of course things like paua and mussels, they have carbonate shells and so the fact is, they're going to find it harder to maintain those shells.

“They’ve got to put more energy into just growing and maintaining a shell and that means they’ve got less energy left for everything else which is going to affect their growth, their reproduction and their ultimate success,” NIWA marine biogeochemist Dr Cliff Law said.

Dr McGowan said in the future, it could lead to restrictions on the fishery but the immediate focus is understanding the long-term impacts of climate change on paua.

Dr Law is part of the team trialling mitigation techniques on mussels for the Sustainable Seas National Science Challenge.

“We’re looking at ways where you can control other stresses in coastal waters… reducing the pressure on things like mussels and paua from other factors like pollution.

“Can you use aeration to drive out the carbon dioxide out of the water, can you actually use all the waste shell that the industry produces because that waste shell is carbonate and if we can get that carbonate back into the water that will actually benefit the mussels on the farm.”

Dr Law said all marine life has the potential to be affected by climate change.

“Whether it be a phytoplankton to fish species everything is moving away from the warmer waters, they're either moving deeper in the ocean or they're moving towards the poles just sort of trying to escape this heating.”

He said the only solution on a global level is to reduce the world’s carbon dioxide emissions.

This story is part of a week of special coverage of climate change from 1 NEWS. Stories in the series include a look at flooding, the situation in farming and ocean temperature rises.

Source: 1 NEWS