Narrator: This is Science Today. Nitrogen is the most abundant element in our atmosphere and a primary nutrient for all green plants. Usually, organisms get this essential element from other sources and yet, there are some organisms that can convert nitrogen gas from the atmosphere for use in their system. Jonathan Zehr, a professor of ocean sciences at the University of California, Santa Cruz, says this conversion is called nitrogen-fixation.
Zehr: In the oceans we're particularly interested in where organisms get nitrogen and how they get nitrogen because in the larger parts of the ocean, there are vanishingly low concentrations of nitrogen.
Narrator: Zehr discovered that the deep ocean is actually teeming with nitrogen-fixing bacteria, which is an important finding because microscopic plants in the oceans depend on nitrogen and this affects fish yields.
Zehr: But on top of that, the availability of nitrogen controls how fast these little plants grow and how much carbon dioxide they can fix - which has implications for the global greenhouse effect and how much carbon dioxide the oceans may be able to absorb.
Narrator: For Science Today, I'm Larissa Branin.