An ecosystem consists of all living plants and animals, and the environment in which these organisms thrive. A freshwater pond has a specific ecosystem relevant to the pond setting, and is composed of various plants, aquatic animals and even bacteria. As with all ecosystems, each element of a freshwater pond's ecosystem is dependent on the other elements and organisms for survival.
The producers of a freshwater pond's ecosystem include rooted or floating plants and phytoplankton. The producers provide crucial nutrients for other organisms of the ecosystem. Water lilies are a common rooted plant in many freshwater ponds, especially man-made ponds. In addition to providing nutrients for the other organisms, these plants also provide oxygen. Curly pond weed, duck weed and marsh marigolds are all common pond producers. Phytoplankton grows in fresh and salt water, and is one of the biggest contributors to the production of oxygen in a pond's ecosystem.
Zooplankton is considered a primary consumer in the ecosystem of a pond. Zooplankton is a floating group of unicellular and multicellular animals. Zooplankton consumes the phytoplankton and is extremely important in connection with the fish population of a pond. Zooplankton is incredibly small, usually invisible to the human eye.
Fish are considered as a secondary consumer in a pond's ecosystem because fish consume zooplankton, the primary consumer. There are many different types of fish in a freshwater pond. Goldfish and koi are most common in small, man-made, backyard-type ponds. Larger freshwater ponds can contain catfish, bass, minnows and carp. Fish are usually at the top of the food chain for ponds, unless the pond contains turtles or ducks, also known as tertiary consumers.
Decomposers and Other Elements
Producers and consumers are the primary elements of a pond's ecosystem, but other elements contribute to the pond's ecology. The sun is an important part of the ecosystem. Without sunlight, the producers would not exist. Fungi and bacteria are another important aspect of the ecosystem, and are known as decomposers. Decomposers break down materials that can be used by consumers, particularly zooplankton.