EH

Aquatic Biomes Study Guide

Objectives

  • Describe the global distribution and environmental aspects of aquatic biomes.
  • Understand freshwater biomes as sources of drinking water.
  • Understand marine biomes as sources of oxygen and carbon dioxide sinks.

Aquatic Biome Characteristics

  1. Salinity

    • Salt concentration affects species survival and water drinkability.
    • Freshwater biomes have low salinity, while marine biomes have high salinity.

  2. Depth

    • Influences sunlight penetration and photosynthesis.
    • The deeper the water, the less light penetrates, affecting plant growth.

  3. Flow

    • Affects dissolved oxygen levels and plant survival.
    • Fast-flowing waters can support more oxygen and diverse species.

  4. Temperature

    • Warmer water holds less dissolved oxygen, supporting less life.
    • Temperature variations can lead to stratification, impacting ecosystem dynamics.

Freshwater Biomes

  • Rivers

    • High dissolved oxygen due to water movement; nutrient-rich sediments support diverse life.

  • Lakes

    • Standing freshwater sources; can provide drinkable water.

  • Littoral Zone

    • Shallow area with emergent plants.

  • Limnetic Zone

    • Area where sunlight penetrates and photosynthesis occurs.

  • Profundal Zone

    • No sunlight; no photosynthesis, colder temperatures.

  • Benthic Zone

    • Murky, nutrient-rich bottom; invertebrates inhabit this zone.

Wetlands

  • Defined as soil that is submerged or saturated with water part of the year.
  • Support emergent vegetation adapted to submerged roots.
  • Benefits of Wetlands
    • Flood control: Acts as a buffer against flooding.
    • Groundwater recharge: Helps maintain aquifer levels.
    • Pollutant filtration: Traps pollutants and sediments.
    • Biodiversity: Supports various species.
  • Types of Wetlands
    • Swamps: Dominated by cypress trees; adapted to submerged soils.
    • Marshes: Characterized by reeds and cattails.
    • Bogs: Formed in acidic conditions; home to spruce trees and sphagnum moss.

Estuaries

  • Mix of freshwater and saltwater where rivers meet oceans.
  • Highly productive biomes with nutrients brought in from river sediments.
  • Salt Marshes: Found in temperate regions; serve as breeding grounds for fish/shellfish.
  • Mangroves: Tropical regions; roots stabilize shorelines and prevent flooding.

Marine Biomes

  • Coral Reefs

    • Located in warm, shallow waters; most biodiverse marine biome.
    • Exhibits a mutualistic relationship between coral (animal) and algae (plant).

  • Intertidal Zones

    • Coastal area between high and low tide.
    • Species must adapt to resist wave action and drying conditions.
    • Example: Seaweed secretes mucus to avoid desiccation.

  • Open Ocean

    • Characterized by low productivity per unit area, but its vast size is crucial for global ecology.
    • Algae and phytoplankton produce substantial oxygen and absorb CO2.

  • Photic Zone

    • Area where sunlight reaches and photosynthesis occurs.

  • Aphotic (Abyssal) Zone

    • Region with no sunlight; no photosynthesis occurs.

Review

  • Practice explaining how abiotic factors like salinity, depth, and flow influence aquatic biomes.
  • Understand how different aquatic zones affect biodiversity and ecological functions.