oligotrofie

Oligotrofie refers to a state of low nutrient availability in an ecosystem, particularly in aquatic environments like lakes and streams. The term "oligotrophic" literally means "poorly nourished." Such environments are characterized by a scarcity of essential nutrients, especially phosphorus and nitrogen, which are critical for plant and algal growth.

Ecosystems with oligotrofie typically have clear water because the low nutrient levels limit the proliferation of phytoplankton and other aquatic plants, which often cause turbidity. This clarity allows sunlight to penetrate deeper into the water column, supporting a diverse community of submerged aquatic vegetation in some cases.

The low productivity associated with oligotrofie means that the overall biomass of organisms is generally lower than in more nutrient-rich environments. Fish populations in oligotrophic waters are often less abundant but can be of high quality, favoring species that require clean, oxygen-rich water. The dissolved oxygen levels are usually high due to the limited decomposition of organic matter.

Human activities, such as agricultural runoff, sewage discharge, and industrial waste, can introduce excess nutrients into oligotrophic systems. This process, known as eutrophication, leads to increased algal blooms, reduced water clarity, depletion of dissolved oxygen, and a decline in biodiversity, transforming the ecosystem into a more eutrophic state. Maintaining oligotrofie is often a goal for water resource management to preserve water quality and ecosystem health.