Kevin Arrigo studies some of the teeny tiniest organisms on the planet -- microscopic plants called Phytoplankton that scientists think might produce up to 50 percent of the Earth’s oxygen. To get at what makes these itty bitties tick he climbs aboard giant ice-breaking ships and heads out to the planet’s icy North and South where they are the most active. Arrigo chatted with us about what it’s like to work in the world’s polar regions and what it feels like to take a wrong step and get a boot full of freezing arctic water.
Do you consider yourself a biologist?
I’m a biological oceanographer. I study the biology of the ocean at a pretty large scale. I’m not a marine biologist. I look at really big ocean issues. One example is the organisms that are the base of the food chain, microscopic phytoplankton. They’re tiny plants that feed everything in the ocean and produce more than 50% of the oxygen we breathe. Most people think of trees, but it’s mostly the phytoplankton that are doing the work.
They’re responsible for the coming and going of the ice ages, which is driven by changes in atmospheric CO2. When the winds pick up, the ocean gets fertilized by iron-rich dust blowing into it. This stimulates phytoplankton to suck CO2 out of the atmosphere and then the planet starts to cool. After thousands of years, the temperatures drop so far that the planet goes into an ice age.
The place I study phytoplankton is in the polar regions. They’re places we don’t understand very well. The North Pole and the area around Antarctica are very different. Most of the climate change is driven by phytoplankton in and around Antarctica. The ones growing in the tropics have very little impact on Earth’s climate.
Around Antarctica, the ocean is a big watery place full of microscopic plants and they need nutrients just like your garden – mostly nitrogen or phosphorus. Luckily the Antarctic has lots of nitrogen and phosphorus, but not much iron. The ocean can become anemic too. Warm times like now, the ocean is really anemic - not much iron is being blown into it.