ELI5: Explain Like I'm 5

Marine biogeochemical cycles

Okay kiddo, let me try and explain marine biogeochemical cycles in a way that you'll understand.

In the ocean, there are a lot of different things moving around, like tiny plants and animals, nutrients (which are like the food for those tiny plants and animals), and gases like oxygen and carbon dioxide. These things all interact and change over time, and that's what we call a biogeochemical cycle.

There are a few different types of cycles that happen in the ocean. One of the most important is the carbon cycle. This is when carbon moves around between the ocean, the atmosphere, and living things. Carbon dioxide (which is a gas that we breathe out) dissolves into the ocean, and then tiny plants called phytoplankton use it to grow. When those plants die, they sink down to the bottom of the ocean and get buried. Over time, that buried carbon can turn into things like oil and gas. Some of the carbon also gets released back into the atmosphere when animals breathe or decompose.

Another important cycle is the nitrogen cycle. Nitrogen is a nutrient that living things need to grow, and it's also important for making proteins, which are like the building blocks of our bodies. In the ocean, nitrogen can come from things like animal waste, but it can also come from the atmosphere. Certain types of bacteria can take nitrogen from the air and turn it into a form that living things can use. Then, when those living things die, their bodies decompose and release nitrogen back into the water.

There are other cycles that happen too, like the oxygen cycle and the phosphorus cycle. All of these cycles are really important for keeping the ocean healthy and balanced. And when the ocean is healthy, that's good for all of us!