This reminds me of Carl Zimmer's disappointingly short (less than 100 pages) new book on viruses, which says that there are trillions of viruses in the ocean and that they kill (cause to decompose) half of the billions of bacteria every day. But of course the bacteria reproduce so fast that they replenish the supply.
There used to be a time when people thought the oceans are pretty much virus-free. But now we realize that there might be, say, maybe a billion viruses in every teaspoon of water. And they're attacking the bacteria. There's lots of bacteria in the ocean. And so they will just do a slaughter of these bacteria every day. Of course, the bacteria grow back pretty fast, but still it's a tremendous thing because all those bacteria contain carbon and lots of nutrients. And so they're constantly cycling all this to the ocean and into the atmosphere.Think about how much is going on that we hadn't even imagined—and how dependent we are on it happening!