APES UNIT 1 - Aquatic biomes

• What is an estuary?

  The transition zone between rivers and the ocean
• What are the characteristics of estuaries?

  They are often characterized by brackish waters and habitats like marshes and mangroves
• What is the largest mangrove habitat in the world?

  The Florida Everglades
• How are aquatic ecosystems connected?

  They are all interconnected through water flow and nutrient cycling
• What is a watershed?

  A land area that channels all snowmelt and rainfall to a singular point
• How does groundwater relate to aquatic systems?

  Groundwater connects marine and freshwater systems
• What is the intertidal zone?

  A zone where high and low tide creates unique communities adapted to changes in moisture, temperature, light availability, and salinity
• What is the significance of the littoral zone?


  It has emergent plants and the greatest biodiversity
• What is the umnetic zone?

  The photic zone where light penetrates, and algae/phytoplankton can be found
• What characterizes the profundal zone?

  It is an aphotic zone where light does not penetrate, is oxygen-poor, sediment-rich, and cold
• What is the benthic zone?

  The bottom of the aquatic ecosystem, nutrient-rich due to sedimentation of organic material
• What is the pelagic zone?

  The open ocean, which is nutrient-poor due to sedimentation of organic material
• What is a hydrothermal vent?


  A location where inorganic molecules may be utilized by chemoautotrophs
• What are the characteristics of the abyssal zone?

  It has no light, is very cold, has very low oxygen, high pressure, and is nutrient-rich and salty
• Why do photoautotrophs need light?

  For photosynthesis
• Who are the primary producers of the pelagic zone?

  Phytoplankton
• How do phytoplankton contribute to oceanic food webs?

  They start off most oceanic food webs
• What are other producers found in shallow waters?

  Coral and kelp
• What is the relationship between producer productivity and dissolved oxygen concentration?

  The productivity of producers is directly correlated with dissolved oxygen concentration
• What is salinity?


  The measure of all the salts dissolved in water
• How does salinity change from rain to the ocean?

  Rain is freshwater, rivers are freshwater, estuaries are brackish, and oceans are salty
• How does salinity change with depth?

  Salinity increases with depth
• What is pH a measure of?

  Acidity
• How does the concentration of H+ ions affect pH?

  The more H+ ions in a concentration, the more acidic the solution
• What is the pH of rainwater?

  1. 2
• What is the pH of pure water?

  1. 0 (neutral)
• What is the pH of seawater?

  1. 6 (slightly basic)
• How does temperature change with distance from the equator?

  Temperature decreases as you move away from the equator
• How does temperature change with depth?

  Temperature decreases as you increase depth
• What is seasonal turnover?

  During the fall, warm surface water cools, becomes denser, and sinks, forcing bottom water to rise
• What are the two qualities of the most productive aquatic ecosystems?

  Exposure to light and a supply of nutrients
• How are nutrients supplied to aquatic ecosystems?

  By sediments being washed into estuaries from the land or from upwelling of deep sea ocean currents
• What happens when phytoplankton have the light and nutrients they need?

  They reproduce, starting many aquatic food chains and making marine life possible
• What human activity can increase sediment run-off?


  Construction, mining, and logging
• What is turbidity?


  A measure of dissolved/suspended solutes
• How does sediment run-off affect aquatic ecosystems?

  It decreases light penetration, decreasing photosynthesis and overall productivity
• What can happen to fish due to sediment entering their gills?

  It can cause suffocation and death
• What is saltwater intrusion?

  The movement of saline water into freshwater aquifers
• What causes saltwater intrusion?

  Aquifers being drained faster than they can be recharged, mostly due to irrigation
• What happens to plants watered with saltwater?

  They will die