- Rocks: stones, pebbles, and boulders that provide shelter for aquatic organisms and help maintain water quality.
- Soil and sediment: the bottom of the pond is covered with soil and sediment, which provide nutrients for plants and animals and serve as a habitat for microorganisms.
- Decaying organic matter: fallen leaves, twigs, and other plant material that break down and release nutrients into the water, supporting the growth of algae and other aquatic plants.
- Dissolved minerals: water in the pond contains dissolved minerals such as calcium, magnesium, and potassium, which are essential for the growth and survival of aquatic organisms.
- Gases: oxygen, carbon dioxide, and other gases are dissolved in the water and are vital for the respiration and survival of aquatic organisms.
- Sunlight: sunlight penetrates the water column and provides energy for photosynthesis, the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen.