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SMS-100

Class 23

Thursday November 20, 2014

The Intertidal Zone: Between High and Low Tides

The Intertidal Zone: Between High and Low Tides

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The Intertidal Zone

Sine Wave

The Intertidal Zone

The Intertidal Zone: e.g., Motile species seeking shelter at low tide

X

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The Intertidal Zone: e.g., flip over a rock:  Sessile & Motile species:

The Rocky Intertidal Zone

The Rocky Intertidal Zone Exposure to:• Air• Waves

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Tide Pools

Tide Pools

Tide Pools

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Tide Pools

Tide Pools

Tide Pools

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Tide Pools

Rocky Intertidal Zonation:

Rocky intertidal zonation:

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Rocky intertidal zonation:

Supratidal:  Salt‐tolerant Lichens

Supratidal Zone

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Supratidal Zone

Supratidal Zone

“Black Tar” Lichens

Attached “blue greens”

“Middle” Intertidal 

Barnacles

Brown and red macroalgae

Blue Mussels

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Rocky Intertidal Zone: Competition for Space   (mid summer)

Mussels and Barnacles overlap…

Rocky Intertidal Zone: Competition for Space   (mid summer)

Mussels and Barnacles overlap… and compete with one another for space on the rocks…

Rocky Intertidal Zone: Competition for Space   (late summer)

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Rocky Intertidal Zone:  Mussels win the competition with barnaclesfor this “wet spot” ?

Blue Mussels

Rocky Intertidal Zone: Competition for Space   (early summer)

Barnacles competing with each other…

Rocky Intertidal Zone: Competition for Space (early summer)

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Rocky Intertidal Zone: Competition for Space   (early summer)

Motile periwinkle snails avoiding desiccation at low tide… 

but not welks…

Soft‐Bottom Environments: Intertidal (mud flats) and Subtidal

Mud bottom continuing sub-tidally

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Intertidal Mud Flat:

Mud Flats:

Soft shell clam: an infaunalSuspension (filter) Feeder

Polychaete worm tubes…Mud Flats:

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Thin layer of brown, oxygenated surface 

sediment

Polychaete tube

Mud Flats:

Black, anoxic subsurface sediment

Sandy Beaches:  (High energy)

Supratidal sand dunes: American beachgrass (Ammophila breviligulata)

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Supratidal sand dunes: Beach grasses… Stabilizes beach sediment (sand)  

against wind and waves

American beachgrass (Ammophila breviligulata).

Root and Rhyzome System…

Supratidal sand dunes: Beach peas

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Salt Marshes

Salt Marshes

Spartinapatens

Spartinaalterniflora

Marsh grasses

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Salt Marshes: Growth

Spartina alterniflora

Roots and Rhizomes

Peat

Mangroves

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Mangroves

Estuaries

Estuaries:

Salt WedgeWell-Mixed

Classification based on Mixing

Partially-Mixed

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Estuaries:

Estuarine Circulation

Halocline

Estuaries: Amplified flows

Coral Reefs

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Coral Reefs

Coral Reef Distributions: require >20°C water temps

Coral Reefs: Internal structure

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Coral Reefs

Coral Reefs: Anatomy & Zooxanthellae

Coral Bleaching

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Coral Bleaching on Australia’s Great Barrier Reef

Coral Bleaching on Australia’s Great Barrier Reef

Temperature Anomaly, 1998 El Nino