Algae that grow on sand, which is hard, relatively inert, and has relatively little surface area. Few algae live in sand among sand grains, because the sand is too unstable and may crush them.

Algae that grow on hard, relatively inert substrata, such as gravel, pebble, cobble, and boulder, that are bigger than most algae.

A complex and diverse group of organisms that are, for the most part, aquatic organisms that obtain energy through photosynthesis and are smaller and less complex than land plants. Algae include cyano [..]

Algae that grow on plants and larger algae, which provide relatively firm substrata that are bigger than the epiphytic algae, but can be highly active metabolically and a great source of nutrients.

Algae that grow on inorganic or organic sediments that are smaller than most unicellular algae. Epipelic algae are typically large motile diatoms, motile filamentous blue-green algae,or larger motile [..]

Microscopic algae that are suspended in the water column.

Any plants or animals that live at least part of their life cycle in fresh water.

Conditions with essentially the same physical, chemical and biological characteristics as found in situations with similar habitats, free from measurable effects of human activity.

(Biocriteria): Numerical values or narrative expressions that describe the condition of aquatic communities and are used to determine if waterbodies are attaining biological goals as described by wate [..]

The ability of an aquatic ecosystem to support and maintain a balanced, adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of natur [..]