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Ocean acidification

Dr. Kumiko Azetsu-Scott studies ocean acidification and explains the price the oceans are paying for absorbing much of the carbon dioxide entering earth's atmosphere.


Ocean Acidification

Melissa Wartman

I originally came because I was interested in marine biology and the whales, but then I got taking some oceanography classes and I just fell in love with the ocean and all that’s in it.

It was interesting to learn more about the chemistry behind it, how CO2 reacts in sea water, and how it’s decreasing the pH through a bunch of reactions.

Kumiko Azetsu-Scott

The ocean takes up a lot of carbon from the atmosphere (after we’re driving the car and heating up the house.)

And that’s a great thing, because otherwise most CO2 would accumulate and more global warming happens - but the oceans have to pay the price for it.

When CO2 dissolves in the ocean… that reacts with water molecules and produces carbonic acid.

That’s acidification.

The first, most direct impact would be the growth of the marine organisms with calcium carbonate skeletons and shells, such as shellfish, deep sea corals, coccolithophores (which is phytoplankton) and pteropods and foraminifera (which is zooplankton).

Zooplankton is the food for the fish, so if you lose that zooplankton, the food source is gone for the fish -- that means fish populations will be affected.

And it’s especially critical for the developing countries - those countries which are very poor and depending on the protein source through seafood.

Those people will be affected, so it’s a huge socio-economic impact.

Canada is a high latitude country, and our ocean is very cold and relatively fresh water. The coast has cold upwelling.

When the wind blows in the right way, the surface water goes offshore.

To replace that surface water, deep water comes up, and this water is naturally corrosive to the organisms, but because of the addition of anthropogenic CO2, the water gets more corrosive now, and that comes to the surface.

The west coast of the U.S. and Canada is suffering this corrosive water already, and those waters come into the Arctic.

And, because of sea ice melt, the water gets less buffered, and acidification intensifies.

And, in the Arctic, already they have found corrosive water in the surface layer …and that flows out … through the Canadian Arctic archipelago and comes to the east coast, and affects the local fisheries.

The monitoring of the ocean is a priority.

It’s important to gather data in climate sciences, so you have to go every year or every season in the same region and understand the change and rate of change.

Melissa Wartman

We’re the future generation that’s going to be trying to help protect and save our oceans, and it’s very important that we know about them.

This is happening.

And, let’s try and prevent it.

Kumiko Azetsu-Scott

The speed of change is much, much faster than any genealogical timescale of the last maybe 25 million years.

The concern is that the rate of change is so rapid, that organisms in the ocean cannot adapt to this speed.

There are no uncertainties about ocean acidification.

As long as the atmospheric CO2 level increases, it’s directly reflected as ocean acidification.

They are exploring the timing of seasonal acidification events.

Studies are underway to develop a coherent response to the issue.

We have to develop a method to adapt to the change in the near future, so we try to find a way to adapt to the new high CO2 world.

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