8 Interesting Facts About Ponds & Lakes

If you have a pond, whether a small garden pond or a larger one, you know that they’re pretty fascinating little ecosystems both from a visual and biological standpoint, with some pretty notable ecological benefits. Chances are, you probably know a great deal about ponds already, but perhaps you’ll come across something new in this list that’ll make you appreciate your unique pond even more.

1) What Makes A Pond, A Pond?

Essentially, ponds are defined as lentic water ecosystems that are able to support (depending upon your location) a fairly diverse range of plants, fish, insects, birds, reptiles, amphibians, and even mammals. Some ponds only occur seasonally (vernal or ephemeral ponds), others exist year round, and still others are created by people – such as within koi and goldfish hobby ponds.

2) Ponds & Lakes Are Different (And Similar!)

If you look up the difference between a lake and pond, you’ll find all sorts of contradictory information regarding what makes a water body one or the other. Size isn’t exactly a guideline, as one would expect; for example, in New Hampshire, Echo Lake is 14 acres with its greatest depth at 11 feet, while Island Pond is about 500 acres with a maximum depth of 80 feet. In some cases, water bodies are named in accordance with what sounds more attractive and will sell more property, as opposed to naming them in accordance with any scientific standard.

Despite this, the overall obvious consensus is that, in general, ponds are smaller than lakes. The one bit of information that seems to be agreed upon is that in a pond, light is able to penetrate to all parts of the bottom of the pond, reaching the sediment below and enabling photosynthesis to occur in all areas of the water. Lakes, by contrast, tend to be deep enough that photosynthesis is only able to occur in the epilimnion, or top layer, of the lake. In addition, because true ponds are typically more shallow than lakes, there is less (or sometimes no) thermal stratification throughout the year, meaning that the water is not deep enough to turn over season to season. To experience thermal stratification, a water body needs to be at least 8 feet in depth – deeper than most garden variety ponds.

3) Healthy Ponds Have Different Wildlife

You likely know that a healthy pond has mostly clear water and a variety of organisms from fish to plants living in it. However, the organisms that are present can tell you a great deal about the water’s general health. For example, the following species are indicators of poor water quality because they are tolerant of (and some even prefer) polluted water with little oxygen: leeches, midge fly larvae and nymphs, black fly larvae and nymphs, flatworms, deer flies and horse flies, lunged snails, abundant amounts of algae, poison ivy, spotted knapweed, and snapping turtles, among others.

On the opposite end of the spectrum, these species are generally correlated with good or acceptable water quality because they are moderately to very sensitive to pollution: salamanders, sedges and rushes, dragonflies and their nymphs, stoneflies, water pennies, mayfly larvae and nymphs, bluebirds, and martins, among others.

It’s important to note that the presence or absence of any species is not a tell-all sign of pond health, especially in man-made garden ponds, so you should still regularly monitor your water quality by checking temperature, dissolved oxygen, pH levels, and nutrient levels.

4) Ponds Are Formed In Unique Ways

Some ponds and lakes are made as glaciers retreat, leaving behind depressions in the ground that fill with water either later on or from the glacier itself. In other cases, seasonal river flooding can leave behind ponds once the flood subsides. Ephemeral ponds are formed in the springtime from melting snow and spring rainfall, and typically dry up after a few months but are home to a sensitive and unique variety of flora and fauna that otherwise would not being able to exist without these springtime ponds – they’re exceptionally important spawning grounds for frogs, for example. Other smaller ponds are formed by animals, such as when beavers create a dam or communities of alligators or crocodiles dig large depressions in the ground for nesting.

Then there are artificial ponds that are created by humans for a multitude of reasons – decoration or gardening, waste water treatment, to create wildlife habitat, fish farming, to water livestock, or as a water reservoir for drinking and recreation.

5) Ponds & Lakes Don’t Last Forever

It makes a certain amount of logical sense that a pond won’t be a pond forever, with the exception of man-made ponds that are continually maintained. Naturally occurring ponds will undergo a phenomenon over time (usually a period of about 100 years) known as ecological succession, in which they gradually change into an entirely different ecosystem. Inevitably, ponds build up thicker and thicker substrate as more and more leaves and other organic matter build up. This results in the pond becoming some form of a wetland – a bog if the area has more acidic soils, a marsh if the soils are rich in minerals, and so on.

Eventually, this wetland in turn becomes a forest, and if left long enough (centuries), that forest will become some sort of open area such as a savanna, prairie, or barrens depending on the location.

6) There are Many Different Types of Ponds

There are five main types of ponds: ephemeral, mountain ponds, meadow-stream ponds, kettle ponds, and farm or garden ponds (essentially man-made ponds). Mountain ponds are formed by glaciers, found at mountainous elevations, and typically have stony bottoms. Meadow-stream ponds are formed by streams or rivers, found in open areas such as meadows, savannas, and grasslands, and usually have a muddy bottom. Kettle ponds are also formed by glaciers, can be found either in mountainous areas of lowlands like meadows, and can either be shallow or as deep as 150 feet (some argue that these are called kettle lakes, though).

7) Ponds Help Wildlife By Providing Safe Havens

Worldwide, natural ponds have decreased in number by an average of 50%. Wetland habitats have diminished by up to 98% in some countries. This is due to the construction of infrastructure, agriculture, roads, and the increasing needs of humans as our population continues to increase and move into new areas. Therefore, your pond can really be an important ecosystem for animals that otherwise would have a difficult time surviving as their natural habitats are either damaged or entirely removed.

Waterfowl will use the pond as a brief stopover point on their way to migrate for the winter; frogs and other amphibians and reptiles will utilize the safe, muddy sediment to overwinter; during droughts, a large variety of animals from deer to songbirds to insects will utilize your pond to get a quick drink; at least some of your plants will likely have flowers, and therefore will help support pollinators like bees that are also struggling to survive (over 50% of bee species are now extinct).

8) Ponds Have Their Place in History

Ponds have held a variety of historical significance over time. In ancient China, ponds were created to stock fish both for decoration and for consumption (these are typically the model after which modern koi ponds are fashioned). Ancient Egyptians figured out how to divert water from the mighty Nile River to create ponds where they could stock tilapia to feed their thriving, ever-expanding civilization.

Many Buddhist temples either created (and some still do) their own ponds or built temples by existing ones, to be used for meditation and bathing. Romans utilized ponds that they called “stews,” which they stocked with breeding populations of mullet, trout, and a variety of other species for food. In portions of medieval Europe, having a pond by your castle was a sign of prosperity. Many Hindu temples in India still keep the ancient tradition of having a pond nearby, considered sacred, that is used by pilgrims and residents alike to bathe and cleanse themselves both physically and spiritually.