Intertidal Zone

By Brian Mullins

Tidal Habitats

Great places to live:

High levels of primary (food) production: driven by phytoplankton

Nutrient rich waters created from river drainage into the sea, and upwelling: the replacement of deep, cold water for surface water driven away by winds.

Different tidal habitats require different adaptations

Sandy Beaches and Mud Flats

Substrate offers lots of nutrients, but little structure for attachment Animals bury themselves in mud Can also attach to plants

Rocky Shores

Little protection from strong waves: animals must anchor Complex tide pools possibleSeaweeds offer protection from drying

Types of Tidal Habitats

Tidal Zones

Tidal habitats are divided into zones based on relative beach location and how often they are covered by water

Splash Zone

High Tide Zone

Middle Tide Zone

Low Tide Zone

Subtidal Zone

Intertidal ZoneHigh, Mid and Low

Zones affected daily by changing tidesMost adaptation required

High Tide ZoneIncreased wave actionSpecies must survive exposure to drying Tide pools provide some protection Higher diversity: includes some animals from splash zone and middle zone (in tide pools)

Low Tide ZoneMost diverse zone: more plants and animals in low tide zone than in all other zones combinedMost food and shelterLess exposure to air and heatAnimals unable to exist in other zones

Subtidal ZoneJust below Intertidal Zone Almost never exposedMany consumer animals: prey on animals in low tide zoneLife forms less tolerant to changes: do not have adaptations to allow them to survive without water

Each zone requires unique adaptations for survival

Splash ZoneHigh Tide ZoneMiddle Tide ZoneLow Tide ZoneSubtidal Zone

Exposure to Water

Pteropurpura_trialata_is_laying_the_eggs_

acornbarnacle

dogwinkles

Pisaster Predate mussels

rockweed

sealettucel

Shorecrab

Human Impact

In addition to climatic impacts, people have a dramatic impact on the intertidal zones. While it's illegal to remove as much as a shell from many tidal pools, there is very limited enforcement so buckets of marine plants and animals are carried away from intertidal zones each day.

Human Impact cont..

That which is not carried away is often crushed or destroyed by sightseers who visit tidal pools and rocky Intertidal zones. This loss and damage affects the biodiversity and food cycle of these precious marine environments. More info at http://geography.about.com/od/physicalge...

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