Aquatic Biome

• Largest part of the biosphere

• Two main types: Freshwater and Marine

• High biodiversity

Freshwater Ecosystem

• 3% of world's water, <1% salt concentration

• Examples: Ponds, lakes, streams, rivers

• Two categories:

  • Lotic System (running water)

  • Lentic System (calm water)

Lotic System (Streams and Rivers)

• Bodies of flowing water

• Higher oxygen levels

• Zones:

  • Headwater Zone: narrow, fast-moving water

  • Transition Zone: deeper, slower, warmer water

  • Floodplain Zone: low oxygen, cloudy water, sediments present

Lentic System (Ponds and Lakes)

• Vary in size

• Limited species diversity due to isolation

• Zones:

  • Littoral Zone: shallow, light-penetrated

  • Limnetic Zone: open water, effective light

  • Profundal Zone: deep, light-absent

• Lake classification:

  • Eutrophic (well-nourished, shallow)

  • Oligotrophic (poorly-nourished, deep)

  • Mesotrophic (moderate nutrients)

Marine Ecosystem

• Largest ecosystem

• Richest diversity of species

• Zones:

  • Intertidal Zone: where ocean meets land

  • Pelagic Zone: open ocean

  • Benthic Zone: below pelagic, not deepest

  • Abyssal Zone: deep ocean, cold, high pressure, low nutrients

Coral Reefs

• Called "Tropical Rainforest of the Ocean"

• Types:

  • Fringing Reefs: near shore

  • Barrier Reefs: 10 km from land

  • Atoll Reefs: circular islands formed from sunk volcanic islands

Estuaries

• Areas where freshwater meets ocean

• Support diverse flora and fauna including algae, seaweeds, crabs, and waterfowl.