Dystrophic lake

[2] The presence of humic substances are mainly due to certain plants in the watersheds of the lakes, such as peat mosses and conifers.

Due to these acidic conditions, few taxa are able to survive, consisting mostly of aquatic plants, algae, phytoplankton, picoplankton, and bacteria.

[7] Lakes typically are categorized according to the increasing productivity as oligotrophic, mesotrophic, eutrophic, and hypereutrophic.

This is due to a wider possible pH range (acidic 4.0 to more neutral 8.0 on occasion) and other fluctuating properties like nutrient availability and chemical composition.

This consists of organic carboxylic and phenolic acids, which keep water pH levels relatively stable, possibly by acting as a natural buffer.

Due to high amounts of organic matter and lack of light, it is bacterioplankton that control the rate of nutrient flux between the aquatic and terrestrial environments.

The chemistry of humic lakes makes it difficult for higher trophic levels such as planktivorous fish to establish themselves, leaving a simplified food web consisting mostly of plants, plankton, and bacteria.

The fish that do adapt to the increased acidity may also not be fit for human consumption, due to the organic pollutants.