Pond Ecology

 Lakes and ponds are bodies of open standing water  Their physical conditions and life vary with distance from the shore.

 Littoral zone: Shallow water at the pond edge. Plants anchor in the mud, leaves reach water surface. Nutrients and plant growth make this zone rich in invertebrates (insect larvae, snails, crayfish)  Benthic Zone: extends along the bottom of the entire pond. Invertebrates live in the mud feeding on detritus (or each other) Zones of life in the Pond

 Limnetic Zone: Open portion away from the shore where sunlight penetrates. Photosynthetic phytoplankton support zooplankton which support fish.  Turbidity affects the depth of sunlight penetration  Profundal Zone: Open water that sunlight does not reach. Low in dissolved oxygen – support few animals

 Streams and runoff naturally bring nutrients and sediment to a pond over time.  Eventually ponds may fill in completely through aquatic succession  Man can accelerate the process of change through the addition of excess nutrients (phosphorus and nitrogen) Eutrophication

Oligotrophic water  Low nutrient  High dissolved oxygen

1.Excess phosphorus enters water 2.Fertilizes algae and aquatic plants making them grow faster 3.Algae can grow quickly and cover the pond surface 4.As algae die bacteria decompose them 5.Increased bacterial activity depletes the dissolved oxygen 6.Dissolved oxygen can become too low to support fish Artificial Eutrophication

Eutrophic water  High nutrient  Low dissolved oxygen