Freshwater

Examples of Freshwater in the following topics:

• Freshwater Biomes

  • Lakes, ponds, rivers, streams, and wetlands are all freshwater biomes, which differ in depth, water movement, and other abiotic factors.
  • Freshwater biomes occur throughout the world's terrestrial biomes.
  • Freshwater marshes and swamps are characterized by slow and steady water flow.
  • Differentiate among the freshwater biomes of lakes and ponds, rivers and streams, and wetlands

• Freshwater Environments

  • Scientifically, freshwater habitats are divided into lentic systems, which are the stillwaters including ponds, lakes, swamps and mires; lotic systems, which are running water; and groundwater which flows in rocks and aquifers.
  • Some protists accomplish this using contractile vacuoles, while freshwater fish excrete excess water via the kidney.

• Osmoregulators and Osmoconformers

  • About 90 percent of bony fish species can live in either freshwater or seawater, but not both.
  • Salmon physiology responds to freshwater and seawater to maintain osmotic balance
  • Fish are osmoregulators, but must use different mechanisms to survive in (a) freshwater or (b) saltwater environments.

• Abiotic Factors Influencing Aquatic Biomes

  • The importance of light in aquatic biomes is central to the communities of organisms found in both freshwater and marine ecosystems.
  • In freshwater systems, stratification due to differences in density is perhaps the most critical abiotic factor and is related to the energy aspects of light.
  • Marine systems are also influenced by large-scale physical water movements, such as currents; these are less important in most freshwater lakes.
  • These realms and zones are relevant to freshwater lakes as well, as they determine the types of organisms that will inhabit each region.

• Bacteroides and Flavobacterium

  • The flavbacterium are characterized by their ability to cause disease in freshwater fish such as salmon and rainbow trouts.
  • Describe the role of Bacteroides in the normal flora of the human gastrointestinal tract and the role of Flavobacterium in causing disease in freshwater fish

• Energy Sources

  • In freshwater systems, the recycling of nutrients occurs in response to air temperature changes.
  • The nutrients at the bottom of lakes are recycled twice each year: in the spring and fall turnover, which recycles nutrients and oxygen from the bottom of a freshwater ecosystem to the top of a body of water.
  • The spring and fall turnovers are important processes in freshwater lakes that act to move the nutrients and oxygen at the bottom of deep lakes to the top.

• Climate Change and Biodiversity

  • Range shifts have also been observed in plants, butterflies, other insects, freshwater fishes, reptiles, and mammals.
  • Additionally, the gradual melting and subsequent refreezing of the poles, glaciers, and higher elevation mountains, a cycle that has provided freshwater to environments for centuries, will also be jeopardized.

• Contractile Vacuoles in Microorganisms

  • In freshwater environments, the concentration of solutes inside the cell is higher than outside the cell.
  • However, not all species that possess a CV are freshwater organisms; some marine and soil microorganisms also have a CV.

• Archaeplastida

  • Other red algae exist in terrestrial or freshwater environments.
  • Chlorophytes primarily inhabit freshwater and damp soil; they are a common component of plankton.

• Wetland Soils

  • The water found in wetlands can be saltwater, freshwater , or brackish .
  • Nutrient cycling in lakes and freshwater wetlands depends heavily on redox conditions.