Marine Aquatic Biomes

Includes: open oceans, coral reefs, coastal wetlands, estuaries; high salt content

Coastal zones:

  • From high-tide to continental shelf

  • 10% of ocean ecosystems, but 90% of biodiversity

    • due to abundance of sunlight and nutrients, the biggest limiting factors

  • warm, nutrient-rich, shallow water

  • Coastal Wetlands:

    • Estuaries: partially enclosed body where freshwater spills from stream/rivers into ocean

    • Coastal & Atoll Lagoons: Seperated from larger bodies by sandbars, barrier reefs, coral reefs, and natural barriers

      • Atoll forms when island is submerged and coral grow upward, and center is pool of water (takes thousands of years to form)

      • Coastal Lagoons: form along coasts with gentle slopes, and are seperated from ocean by island, reef, or sand bank (deposit of sand)

    • Tidal Flats: areas where sediments from river runoff / tides deposite mud/sand

      • border estuary

    • Salt Marsh: tidal flat that is dominated by herbaceous plants (grasses and shrubs)

    • SeaGrass Beds: Wetlands w/ plants that have long narrow leaves

      • shalow marine life, highly diverse and productive

    • Mangrove Forests: Wetlands w/ trees that evolved to survive high-salt low-oxygen water & wave action

      • where rainforrests meets oceans

    • Wetlands are highly productive, serve as nurseries (protects aquatic species & support biodiversity), slow influxes of water → prevent floods, and filter out sediment and pollution

  • Intertidal Zone: moon/sun gravitational pull causes tides to rise/fall, so there exists zone that’s submerged during hightide and exposed during lowtide

  • Coral Reefs

    • contain coral polyps = small animals that live in warm coastal waters of tropics/subtropics

      • coral provides home, photosynthetic algae produce for polyps

    • most diverse & productive ecosystem in ocean

Open Ocean: (more distance from coast → less nutrients, a limiting factor for life)

  • Open Ocean = marine deserve due to lack of life → animals must be able to travel long distance for food

    • Food webs in abyssal plain/benthic zone are based on scavenging and decomposing

  • Many species are bioluminescent (attracts prey / mates)

  • Hydrothermal Vents: heated water & minerals are released into water

    • some organisms use as source of energy: chemosynthesis

  • Ocean Acidification: ocean absorbs 30% of CO2 that is released into atmosphere, so increased CO2 → more hydrogen ions released → more carbonic acid in water→ carbonic acid steals carbonate ions

    • carbonate ions are vital for sea shells, coral skeletons,