What’s the difference between a lake and a pond?

06/28/11

lake or a pond?Most would say it’s size, a lake is bigger, a pond is smaller. That’s actually wrong. From government websites to Wikipedia, the information is wrong. The difference is actually a result of the the depth.

Ponds, according to limnology (the study of water bodies) are shallow enough where plants could conceivably grow across the entire surface. This area, where plants could grow is known as the “photic zone,” meaning where the sun’s rays can reach the bottom.

A lake, by contrast, has an “aphotic zone,” meaning there is an area deep enough that sunlight can’t reach the bottom.

As a result, there are some very small bodies of water, less than an acre that are deep enough to be called lakes. Conversely, there are some very large, but shallow water bodies, particularly in the south that are technically ponds, (though they’re called lakes) because their “photic zone” expands the entire length and width.

So, at least with lakes and ponds, size doesn’t really matter.

Now, what if a lake became infested with zebra mussels, which cleared the water to the point where lake weeds could grow in depths where they couldn’t before? The jury’s out, but I’d say if it was once a lake, it should continue to be an “honorary” lake.

Tags: Depth, Lake, Pond