For the first twenty-seven years I lived in my home, the water in the lake out back was a dark-green color—from the algae in the water—that prevented any possibility of seeing the lake bottom. This is true of pretty much every body of fresh water in Georgia. About four years ago, however, the water began to clear up, and by the next summer the water was clear enough that we could see the bottom easily.
I was puzzled by this, and despite thinking of all the possibilities I knew, I could come up with no solution. I finally gave in and called the county wildlife and agriculture agent, but he was similarly stumped for an answer.
One day I read an article about the ecosystem of the Great Lakes—yes, I know, who does that?—and I solved the mystery. For twenty-six years, the mud on the bottom of our lake had been the kind of fine, slimy stuff that people pay to have slathered on their bodies in high-end spas. But then I began to notice the presence of tiny mussels in the first few inches of the mud—almost certainly introduced by some small boat carrying a few of them from another lake. As their numbers rapidly multiplied, the water quickly cleared.
It turns out that although each mussel is about the size of the end of my small finger, it filters almost an entire liter of water a day, removing zooplankton, algae, other phytoplankton, and fine inert particles. Performing a sampling of the lake bottom, I calculated that approximately 5.4 million mussels were recycling all the water of the lake about every two days, and that is how the lake water became clear.
One mussel has no discernible effect on a natural body of water, but 5.4 million of them combine to create quite a powerful filter. Similarly, one good decision may make no visible difference in someone’s life, but one after another creates an exponential effect that creates character, builds emotional strength, eliminates fear, and guarantees happiness. If we want to be happy, we need to evaluate each choice according to the criteria of love and responsibility, and from such evaluations we create the life we want.