Transcript Life on the Sea Floor - WHS

Life on the Sea Floor
Review
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Benthic environment
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Life Groups
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Regions of land above/below water
Supralittoral, Littoral, Sublittoral, Bathyal,
Abyssal, Hadal
Plankton (floaters/drifters; at/near surface)
Nekton (swimmers)
Benthos (at/near bottom)
Importance of Benthic Organisms
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Food resources, Commercial harvests
Seaweeds
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Not plants just plant-like algae/protist
Found in Euphotic zones
Provide food, shelter, attachment
Adapted to deal with tidal, current, and
wave action
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Holdfast, Stipe, blades, air-filled structures
Groups based upon pigments
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Green-chlorophyll (ROY BIV)
Brown-fucoxanthin
Red-phycoerythrin and phycocyanin
Seaweed Groups
Plants
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Few marine plants
Eelgrass
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Turtle grass- Gulf of Mexico only
Surf grass
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Areas of more turbulent areas
Marsh grasses
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Areas of less wave action; Pacific/Atlantic
Dominate estuaries/salt marshes
Mangrove Trees-tropics only
Animals
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More than 150,000 species
80% are epifauna (live on/attached to bottom)
20% are infauna (buried in sediments)
Can be sessile or motile
Larvae is all motile to prevent overcrowding and
for colonization of new areas
Type of substrate, temperature, pH, salinity,
exposure to air, Oxygen levels in water, water
turbulence, pressure all influence type of life
found in benthic environments
Rocky Shores
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Extreme environment
Distribution based on ability to cope
Intertidal Zonation
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Varies with local conditions
Distinct arrangement of organisms
Tidal Pools
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Receding water trapped in a depression
Organisms are specialized to deal with
changes in salinity and temperature
Deeper pools mean greater volume of
water which means a more stable
environment
Sand & Mud
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Mostly detritus feeders buried in the
sediments
Anoxic layers have little/no oxygen present
Sea Floor
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Bioturbation
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Organisms such as sea cucumbers and worms
that continuously disturb and rework
sediment so that there is a well-mixed
uniform layer on the sea floor
Fouling & Boring
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Fouling organisms
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Settle and grow on pilings, docks, boat hulls
Boring organisms
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Drill or bore their way into substrate
Symbiosis
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Relationship between two organisms living
closely together
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Mutualism
Commensalism
Parasitism
Coral Reefs
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Location in tropics (23.5 degrees N & S)
Colony of polyps that make calcium carbonate
Need for survival
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Warm water
Clear water
High wave energy
Shallow water
Symbiotic relationship with Zooxanthellae
Can be found in deep water
Threats to Coral Reefs
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Overfishing
Poverty
Predation
Coral Bleaching
Diseases: CLOD, Black Band
Increase sedimentation
Harvesting Benthic Creatures
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Commercial harvesting
Algae and their extractions
Therapeutic uses