The Marine Biome

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The Marine Biome

• Cycle carbon dioxide and oxygen on Earth
• Modifies temperatures changes
• Most important provides stability to the web of
  life on Earth

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The World Ocean

• World ocean is divided into zones based on depth
  and distance from the shore
• Depth zones photic, aphotic, benthic zones
• Shore distance zones oceanic, neritic,
  intertidal zones

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Oceanic Zone

• This is the open ocean
• Largest zone in the ocean, 90 of the world ocean
• Ranges in depth 500 meters to 11,000 meters deep
• Not much sunlight penetrates into the oceanic
  zone
• Photic zone is only at the surface, about 200 m
  deep
• Only phytoplankton are the producers
• They convert CO2 into billions of tons of carbon
  each year
• This provides the basic material for the bottom
  of the food web
• Plankton is the food source for both large and
  small ocean animals fish and whales

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• Aphotic zone-takes up most of the world ocean,
  but does not have much organism diversity
• Limited by absence of sunlight
• Organisms have to adapt to cold, dark, deep water
• Feed on pieces of dead organic material that
  sinks down from surface
• Detritus-tiny pieces of dead organic material
  that are food for organisms at the base of an
  aquatic food web
• Clams, worms, sponges all feed on detritus

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• Neritic Zones
• Neritic zone- the ocean region b/n the edge
• of the continental shelf (500 m below
• Sea level) and the low tidemark
• Its usually shallow, so gets sunlight for
• photosynthesis, therefore most productive
• Only 10 of the ocean
• Neritic zones include reefs and estuaries

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• Coral Reefs
• Reef- natural structure built on a continental
  shelf
• Coral reefs found in warm, tropical waters
• Kelp reefs found in cold waters
• Importance of coral reefs
• Home to huge variety of organisms
• Breeding and feeding place for many fish
• 1/3 of all ocean fish live on or depend on coral
  reefs
• Protects shoreline from erosion
• Many coral reef organisms have medical benefits

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• Coral reefs are very fragile
• Made of calcium carbonate skeletons of millions
  of tiny corals
• Top layer is alive
• Zooxanthellae alga lives inside tissue of coral
• Alga perform photosynthesis and provide food to
  coral
• Human Damage of coral reefs
• Blast reefs to make harbors
• Coral is harvested for jewelry
• Fish are popular for home aquariums
• Collecting the fish damages the coral

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• Water pollution damage
• Toxic chemicals kill coral and organisms
• Silt, sand, and topsoil wash into the water and
  make it cloudy, less light for photosynthesis
• So can look at health of coral reef to determine
  the quality of water
• When coral reefs start to die, start to
  investigate the water quality
• Estuaries
• Region where a freshwater source, usually mouth
  of a river, meets the saltwater of the ocean
• Water is usually brackish here

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• Nutrients and sediments are mixed here
• Many marine organisms breed here, commercially
  important
• Function as buffer zone, filter sediments and
  pollutants from the water
• Slow down floods and storm water
• Humans use for boating, fishing, hunting
• Neritic Zone Production
• Sunlight can reach it, so photosynthesis occurs
• Many mineral nutrients wash into the zone from
  the shore
• Tides wash in fresh nutrients and O2, and takes
  away waste

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• Fringe reefs-grows just off shoreline
• The reef will keep growing farther out
• The reef closest to the shore will start to die,
  creating a channel
• Forms a barrier reef- reefs that are separated
  from the shore by a channel
• Great Barrier Reef in Australia is largest coral
  reef in world

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Intertidal Zones

• This zone located along the shoreline
• Alternates twice a day b/n periods of exposure at
  low tide and periods of submersion at high tide
• 2 high tides and 2 low tides each day
• Any organisms living there must be able to
  withstand these constant changes, and pounding of
  water
• Attach to rocks, burrow in sand
• Often surrounded wetlands salt marshes and
  mangrove swamps

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Salt Marshes

• Flat, muddy wetlands surround estuaries, bays,
  and lagoons
• Mud floor is exposed during low tides, and
  submerged during high tides
• Common in US coasts, especially east coast
• Functions
• Support migratory bird populations feeding and
  resting grounds in b/n journeys
• Plant life (grasses) support rich community of
  fish and invertebrates
• Many shellfish and fish spend part of their life
  there, so they can be easily captured for sale
• Plants are their food and protection

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• Salt Marsh Formation
• Streams flow into an estuary or shallow, neritic
  water
• Sediments are deposited at the mouth of the
  stream, and build up forming a delta
• the delta begins to sink. Subsidence-the weight
  of accumulated sediments cause the delta to sink
  under the water
• The amount that sinks has to balance the amount
  that is deposited for a salt marsh to remain
• This sinking and depositing of sediments causes
  the river to change its course many times

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Mangrove Swamps

• Coastal wetland that occurs only in warm climates
• Named after the mangrove plant that lives there
• Mangroves cannot grow in areas that freeze more
  than 2 days a year
• Mangroves can either be a tree or shrub, 800
  species total, 10 live in US
• Most common in US is red mangrove
• Adaptations
• Low O2 in swamps
• Mangroves have roots that grow up and stick out
  of the water
• Some have roots that grow high on the trunk, look
  like stilts

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• Mangrove swamps are being destroyed at a high
  rates
• Make great commercial fish and shrimp ponds
• Construction projects
• Waste dumping