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.