Science From the Bottom of the World

The world's oceans, the creatures that live within, and the climate influenced by those oceans are all connected. North Carolina researchers are studying how melting Antarctic glaciers will affect the Atlantic Ocean and the state's coastal resources.

Remember “Gill,” the moorish idol fish and leader of the Tank Gang in Disney’s Finding Nemo? In explaining to Nemo his latest plan to escape from the aquarium tank in the dentist’s office, Gill tells Nemo that the way to freedom lies down the drain in the sink because “all drains lead to the sea.”

That quote not only explains part of the plot in the movie, it also explains why Dr. Reide Corbett is in Antarctica. Reide is a professor and research scientist at the Institute for Coastal Science and Policy at East Carolina University and the co-program head at the UNC Coastal Studies Institute. He’s studying glaciers and the effect of glacier melt on the southern ocean because all that melting water “leads to the sea.”

“One of the interesting things about the Antarctic, and especially the western Antarctic peninsula where we are doing our work, is that it’s changing faster than most places on earth,” Corbett explained. “It’s one of the fastest warming places on the planet, and so the changes that are happening are happening rapidly, from a climate, biological, chemical perspective."

The key to understanding the work that Dr. Corbett and his team of researchers from the University of North Carolina Coastal Studies Institute are doing is to look at what is in the water that is flowing to the ocean. The water contains iron.

That’s because, as the water runs off the continent or as it seeps into the ground, and then flows to the ocean as groundwater, it picks up iron and other chemicals along the way. And iron is an important nutrient in the southern ocean. The more iron in the water, the greater the numbers of tiny organisms like phytoplankton, which form the base of the food chain, are produced. As the Antarctic summer sun warms the water, tremendous blooms of algae and other organisms are produced. At first, that sounds like a good thing - more food, more sea life, etc. But it is changing nature’s balance in the ocean.

“The amount of primary production that takes place in the southern ocean is greater than many places across the planet, and it does fuel the secondary and tertiary production across the planet,” adds Dr. Corbett.

So the researchers will spend several months working out of Palmer Station, one of three bases the United States’ operates on the continent. The work is being conducted during the Antarctic summer and the weather conditions at the Bottom of the World are similar to a normal winter in North Carolina.

The team will collect and analyze hundreds of water samples taken close to shore and in the open ocean. They will also collect soil samples from the ocean floor. It’s all in an effort to understand and quantify how much freshwater is flowing into the ocean and the amount of iron and other chemicals the water is carrying. Scientists hypothesize that the exchange of groundwater between land and ocean will significantly increase the amount of iron found in the waters close to shore as well as in the deeper ocean.

That could affect the amount of food that is available to creatures at the bottom of the food chain in the southern ocean. That abundance of food would then, in turn, influence creatures farther up the food chain. 

But it’s not only the food chain that could be affected by all the freshwater from the glaciers. There’s also a question of how the influx of freshwater will affect the ocean waters and currents.

“As we change the density of the ocean by increasing freshwater delivery to the ocean, there’s a question of whether that can have an influence on the physics of the ocean, and the currents of the ocean like the Gulf Stream,” said Dr. Corbett, as he showed off a giant map of the world and the flow of ocean currents. “That would then influence the biology of the ocean because it’s this large scale ocean circulation which does drive the biology, the chemistry and the life in the ocean.”

Essentially, Dr. Corbett stresses that what happens at the Bottom of the World does influence what happens off the coast of North Carolina. While the locations are thousands of miles apart, all of the natural systems on the globe are interconnected. So while the freshwater runoff from the melting glaciers will likely change the ocean, nobody knows if that change will be good or bad. Dr. Corbett hopes to find out.

“It’s hard to put those together, North Carolina and Antarctica, but what’s happening there influences primary production in the southern ocean,” adds Dr. Corbett. “And what’s happening in the southern ocean influences the biology across the global ocean.”

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