Properties of Aquatic Environments

• what % of water is freshwater?

  3%
• what are the eight basic characteristics of aquatic environments?

  salinity, physical structure, flow, mixing, temperature, oxygen, nutrients, light
• what are the two primary ions in aquatic environments?

  sodium and chloride ions
• where is brackish water found?

  estuaries
• what are the two types of physical structure of aquatic environments?

  lotic and lentic
• what is an aquatic environment with running water referred to as?

  lotic
• what is an aquatic environment with standing water referred to as?

  lentic
• what is used to classify streams?

  their order or strahler number
• what are the three zones in aquatic habitats?

  littoral, pelagic and benthic
• what is the shallow zone near the shore edges referred to as?

  littoral zone
• what is the open water in the middle of a body of water referred to as?

  pelagic zone
• what is the area near the bottom sediments referred to as?

  benthic zone
• what is water movement like in lotic bodies?

  shallowing and swirling
• what is water movement like in lentic bodies of water?

  deep and peripheral
• what are the two ways in which flow in rivers can be measured?

  velocity and discharge
• what are the three types of flow regime?

  simple, double or complex
• what is a simple flow regime?

  when there is one maximum and one minimum annually
• what is a double flow regime?

  when there are two maximums and minimums annually
• what is a complex flow regime?

  when there are more than two maximums and minimums annually
• what can a double flow regime also be referred to as?

  mixed
• how is vertical stratification maintained?

  the density of water
• why will some water be less dense in an aquatic environment?

  heat from the sun warms the water, making it less dense
• what does salinity refer to?


  the amount of ions called salts dissolved in water
• what are the four ways in which water can be divided based on salinity?

  fresh water, brackish water (estuaries), saline water (oceans) and hyper saline water (saline lakes)
• what are lotic bodies?

  running water
• what are lentic bodies?

  standing water
• where is the benthic zone?

  the ocean floor near the bottom sediments
• where is the pelagic zone?

  open water in the middle of a body
• where is the littoral zone?

  shallow edge shores
• what is the flow of water like in lotic bodies?

  shallow and swirling
• what is the flow of water like in lentic bodies?

  deep peripheral movement
• what type of relationship is there between flow and physical structure?

  bi-lateral
• what is a flow regime?

  a description of the flow structure or a distribution of one fluid phase in relation to another
• why do layers form in bodies of water?

  because there is limited kinetic energy from the wind available to mix the water
• what is vertical stratification maintained by?

  the density of water
• why is the water in the top layer of a body of water less dense than that below?

  the sun shines on the top layer of the water and makes it warmer and less dense
• what are mixing regimes in lakes categorised by?

  frequency of stratification and turnover
• what are the two types of 'turnover' in relation to mixing in bodies of water ?

  monomictic and dimictic
• what does monomictic mean?

  mixing one time per year
• what does dimictic mean?

  mixing two times per year