Ch16

• Benthic communities discussed in this chapter:

  • Rocky intertidal community
  • Sandy/cobble beach community
  • Salt marsh & estuary community
  • Coral reef community
  • Deep sea floor community
  • Hydrothermal vent community
• Habitat: the natural environment where an organism lives (its address)

  Niche: an organism’s role in the environment
• Stenothermal - organisms that have narrow tolerance to temperature ex: coral

  Eurythermal - organisms that have a wide tolerance to temperature ex: sperm whale

  Stenohaline - organisms require a stable saline environment ex: haddock

  Euryhaline - organisms that can withstand a wide range of salinity ex: bull shark
• Population: group of organisms of the same species that occupy a specific area

  Community: comprised of the many populations of organisms that interact at a particular location
• Biotic factors that affect organisms in an ecosystem:

  • Competition – intra-specific and inter-specific
  • Symbioses – such as parasitism, commensalism or mutualism
  • Predation
  • Disease – such as SCTLD – stony coral tissue loss disease
• Layers in the ocean:

  • Neritic zone - near shore over continental shelf
  • Oceanic zone - deep water beyond continental shelf
  • Epipelagic zone - the zone of the ocean between 0-200m deep which receives enough light for photosynthesis
  • Mesopelagic – the zone of the ocean b/t 200-1000m deep which receives very little light
  • Bathypelagic – the zone of the ocean b/t 1000-4000m deep which receives no sunlight
  • Abyssopelagic – the zone of the ocean b/t 4000-6000m deep with near freezing water temps and intense pressure
• Ecosystem services provided by the ocean:

  1. Carbon Sink – Carbon dioxide dissolves into the ocean from the atmosphere.

  2. Source of oxygen – Phytoplankton release oxygen through photosynthesis.

  3. Temperature Buffering – can buffer temperature due to water’s high heat capacity.

  4. Global climate control – regulates long term climate also due to its high heat capacity

  5. Food Source
• Two types of competition:

  • Intra-specific – which occurs b/t individuals of the same species
  • Inter-specific – which occurs b/t members of different species
• Organisms in intertidal regions withstand wave action by:

  • Hiding/burrowing
  • Attaching themselves to rocks
  • Sliding into cracks in rocks
  • Running away to avoid wave action
• Importance of marine biodiversity:

  • Maintaining stable ecosystems
  • Protection of physical environment
  • Climate control
  • Providing food sources
  • Source of medicine
• Distribution patterns of organisms:

  • Random distribution
  • Clumped distribution
  • Uniform distribution
• Major zones of rocky intertidal zones:

  • Splash Zone
  • Upper Shore
  • Middle Shore
  • Lower Shore
• Epifauna: Live on the bottom but generally stay on substrate surface (attached = sessile, freely moving = motile) ex. Brittle star

  Meiofauna: Live in the spaces between sand/sediment grains (interstitial) ex. Tiny worms; microscopic

  Infauna: Live buried in the substrate (sand, mud, etc) ex. Cockle shells, lugworm, sand flea
• Chemosynthetic bacteria is essential to deep-sea vent communities and produces carbohydrates using hydrogen sulfide from hydrothermal vents
• Brackish water is a mixture of fresh and salt water
• Explanation of different communities:

  • Coral Reefs
  • Sandy Beaches
  • Rocky Intertidal zone
  • Salt Marsh & Estuaries
  • Deep Sea Community (not near a vent)
  • Hydrothermal Vents
• Ranking of communities from highest to lowest biodiversity:

  1. Coral reef

  2. Intertidal rocky shore

  3. Estuary

  4. Sandy beach

  5. Deep sea community (not associated with hydrothermal vents)

  6. Hydrothermal vents