Freshwater Ecosystems

Freshwater ecosystems cover only 3% of the Earth's surface but support a vast array of plant and animal life
Freshwater habitats include rivers, lakes, wetlands, and groundwater
Freshwater ecosystems are characterized by low salt concentrations, variable temperatures, and limited nutrient availability

Phytoplankton: microscopic plants that form the base of freshwater food webs
- Examples: algae, cyanobacteria
Zooplankton: small, usually microscopic animals that feed on phytoplankton
- Examples: rotifers, copepods
Benthic organisms: plants and animals that live on or in the sediment of freshwater habitats
- Examples: aquatic plants, insects, crustaceans
Nekton: free-swimming animals that live in freshwater habitats
- Examples: fish, amphibians, turtles

Osmoregulation: the ability to regulate the concentration of salts and water in the body
Buoyancy: the ability to maintain a stable position in the water column
Specialized sensory systems: adapted to detect vibrations, changes in water pressure, and visual cues in low-light environments
Thermoregulation: the ability to regulate body temperature in response to changing water temperatures

Water purification: freshwater organisms help to remove pollutants and excess nutrients from the water
Food source: freshwater organisms provide a source of food for humans and wildlife
Shelter and habitat: freshwater habitats provide shelter and habitat for a diverse range of plants and animals
Recreation: freshwater ecosystems offer opportunities for recreation, tourism, and relaxation

Habitat destruction: human activities such as dam construction, water diversion, and habitat destruction
Pollution: chemical pollutants, excess nutrients, and invasive species can harm freshwater organisms
Climate change: changes in temperature and precipitation patterns can alter freshwater habitats and disrupt the distribution of freshwater organisms
Overfishing: the removal of too many fish and other aquatic organisms can disrupt the balance of freshwater ecosystems

Freshwater ecosystems cover only 3% of the Earth's surface but support a vast array of plant and animal life
Freshwater habitats include rivers, lakes, wetlands, and groundwater
Freshwater ecosystems are characterized by low salt concentrations, variable temperatures, and limited nutrient availability

Phytoplankton are microscopic plants that form the base of freshwater food webs, examples include algae and cyanobacteria
Zooplankton are small, usually microscopic animals that feed on phytoplankton, examples include rotifers and copepods
Benthic organisms are plants and animals that live on or in the sediment of freshwater habitats, examples include aquatic plants, insects, and crustaceans
Nekton are free-swimming animals that live in freshwater habitats, examples include fish, amphibians, and turtles

Osmoregulation is the ability to regulate the concentration of salts and water in the body
Buoyancy is the ability to maintain a stable position in the water column
Freshwater organisms have specialized sensory systems adapted to detect vibrations, changes in water pressure, and visual cues in low-light environments
Thermoregulation is the ability to regulate body temperature in response to changing water temperatures

Freshwater organisms help to remove pollutants and excess nutrients from the water through water purification
Freshwater organisms provide a source of food for humans and wildlife
Freshwater habitats provide shelter and habitat for a diverse range of plants and animals
Freshwater ecosystems offer opportunities for recreation, tourism, and relaxation

Habitat destruction is a threat to freshwater life, caused by human activities such as dam construction, water diversion, and habitat destruction
Pollution is a threat to freshwater life, caused by chemical pollutants, excess nutrients, and invasive species
Climate change is a threat to freshwater life, caused by changes in temperature and precipitation patterns that alter freshwater habitats and disrupt the distribution of freshwater organisms
Overfishing is a threat to freshwater life, caused by the removal of too many fish and other aquatic organisms that disrupt the balance of freshwater ecosystems