Topics: Intertidal zone, Tide, Tide pool Pages: 2 (322 words) Published: February 19, 2014
Intertidal Zones

The intertidal zone, also known as the littoral zone, in marine aquatic environments is the area of the foreshore and seabed that is exposed to the air at low tide and submerged at high tide, it is the area between tide marks.

In the intertidal zone the most common organisms are small and most are relatively uncomplicated organisms. This is for a variety of reasons; firstly the supply of water that marine organisms require to survive is intermittent. Secondly, the wave action around the shore can wash away poorly suited or adapted organisms. Thirdly, because of the intertidal zone's high exposure to the sun the temperature range can be extreme from very hot to near freezing in frigid climates (with cold seas). Lastly, the salinity is much higher in the intertidal zone because salt water trapped in rock pools evaporates leaving behind salt deposits. These four factors make the intertidal zone an extreme environment in which to live.

The high intertidal is flooded during the peaks of the once or twice daily high tides, and out of water for the long stretches in between.

Purple Shoreline Crab
Blue-Green Seaweed

The middle intertidal zone is generally submerged, except for a fairly short period during the turn of the low tide.

Mussel Bed
Sea Urchin
Sea Stars and Anemones

The lower intertidal zone is exposed only during the lowest spring tides.

Red Algae
Dungeness Crab
Sea Star and Sea Urchins

Threats to the Intertidal Zone:
Visitors: People are one of the biggest threats to the intertidal zone, as tide pools are popular attractions. The cumulative impact of people exploring tide pools and stepping on organisms and their habitat, and sometimes taking creatures, has resulted in a decrease in organisms in some areas. Coastal Development: Pollution and runoff from increased...
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