What Is a Pond Ecosystem?
While many think of manmade water features when they hear the word “pond,” ponds are more than just decorative garden elements. In fact, there are plenty of naturally occurring ponds in a variety of different climates all over the world.
Moreover, ponds are a recognized ecosystem; their features distinguish them from other bodies of water, such as lakes or streams, and, of course, pond ecosystems serve an essential role. So, what is a pond ecosystem — and what types of organisms live in ponds? We’re delving into these questions in more as we plunge into the world of ponds.
What Is a Pond Ecosystem?
A pond ecosystem involves the land that makes up the shoreline, the water that fills the pond, the life at the bottom of the pond, and the air above the pond. Within these ecosystems are animals that crawl, walk, swim, and fly.
By the Environmental Protection Agency’s (EPA) definition, a pond is a body of water shallow enough for sunlight to reach its bottom. Usually, ponds are separate from other bodies of water, but they can be connected to oceans. Ponds connected to oceans are called lagoons. Large ponds are called lakes.
Since ponds are not often connected to larger bodies of water, the water contained in a pond does not flow through it. Large ponds can have movement created by wind currents, but pond water is always much more stagnant than in a river or ocean.
Types of Pond Ecosystems
A pond can be classified as any body of water that fills a hole in the ground. An interesting implication of that definition is that a pond can be both naturally occurring or manmade. Both naturally occurring ponds and manmade ponds, such as those found in gardens and suburban neighborhoods, can support ecosystems similar to natural ones when cared for properly.
Classifications of Pond Ecosystems
There are a variety of types of natural ponds. Freshwater ponds are the most common. Brackish ponds are made from a mixture of saltwater and freshwater. Vernal ponds happen when there is a large hole in the ground. These ponds can appear during rainy seasons and disappear during dry seasons. There are even some underground ponds that are water-filled cavities that were created by underground rock formations.
Pond Ecosystem Factors
Pond ecosystems are made up of a network of living (biotic) and non-living (abiotic) factors that keep the environment working. Let’s take an in-depth look at both types of factors. First up? Abiotic factors.
Sunlight is one abiotic factor that a pond ecosystem cannot survive without. Without sunlight, plants cannot grow and make energy for all of the animals that eat them. When a pond does not have plenty of access to sunlight, there is a risk of the entire ecosystem collapsing due to a lack of food. The amount of sunlight a pond receives also has a direct impact on its temperature. Some animals can survive in colder water, whereas others need a warmer environment to thrive.
Water is perhaps the most obvious abiotic factor within a pond ecosystem. The water provides a home for all of the plant and animal life in the ecosystem. This home is uniquely suited for fish gills to capture oxygen and for plants to grow. Animals in pond ecosystems have fins, webbed feet, “waterproof” fur or feathers, and other body features that help them to move efficiently through the water.
Beyond simply being a place to exist, there are also many specific factors of water that make the pond ecosystem unique. For example, most ponds have low salt levels or salinity. In the average pond, the level of salt is at our below 3,000 parts per million. The salinity of ponds is specifically made to support the plant and animal life native to the environment. Aquatic plants and animals are often very sensitive to the amount of salt in the water. That’s why you don’t see sharks and coral reefs at your local pond.
Dissolved oxygen is one of the most precious resources in a pond ecosystem. Oxygen is a byproduct of photosynthesis, the process that plants within a pond use to make energy. This same dissolved oxygen is necessary for other animals in the ecosystem to survive by breathing it in. If too many plants grow in an ecosystem, the plants can block out the sunlight. Without adequate sunlight, plants start to die, and their decomposition process removes dissolved oxygen from the water. Eventually, there are so many living and dead plants that sunlight is almost completely blocked out and the water does not have enough oxygen to support life. Overgrowth of plants often happens when animal waste and fertilizer enters a pond as runoff.
Biotic components of a pond ecosystem are extremely varied depending on climate. Plants and phytoplankton are an important food source for the animals that live in a pond ecosystem. Algae and various forms of water lilies are common in many pond ecosystems. Microscopic bacteria and protozoa help to ensure that the soil within the ecosystem has enough nutrients to support healthy plant life.
Ducks, geese, and other waterfowl are common in ponds. Reptiles like toads, frogs, snakes, and turtles frequent pond ecosystems. Larger mammals like raccoons and otters also live in ponds. Of course, one of the most plentiful types of animal life in any pond is fish.
Organisms That Live in Ponds
Fish, bugs, birds, plants, and microscopic bacteria and plankton are just a few of the different organisms that are part of a pond ecosystem. Since many of the organisms in a pond ecosystem cannot leave the pond, the organisms fulfill very specific needs for each other.
Food Chain in Pond Ecosystem
The pond ecosystem food web has three levels. The pond ecosystem food chain starts with producers. These are plants and other phytoplankton that use sunlight to produce their own food, a source of plant energy called ATP, through photosynthesis. Phytoplankton are tiny unicellular organisms. In other words, these tiny green organisms often have only one cell.
Next, primary consumers get energy from producers by eating them. Zooplankton are the most common primary consumers in a pond ecosystem. These microscopic organisms are animals, and they can have more than one cell. Tadpoles, for example, are primary consumers that commonly eat producers.
Secondary consumers make up the third level of the pond food chain. These biotic organisms eat primary consumers, the animals that eat plants. Otters, frogs, snakes, and hawks are all examples of secondary consumers that are part of pond ecosystems.
Importance of Pond Ecosystems
Ponds are important features of the environment because they are like a large water filter. As the abiotic factors in a pond use water and oxygen to grow and survive, pollutants and excess natural chemicals in the water are filtered out. When cleaner water is evaporated, better water re-enters the water cycle. The filtration that occurs in brackish ponds is even more valuable because these ponds stop polluted water from entering the ocean.