The intertidal zone -- the area between high and low tides -- is a harsh and unforgiving habitat, subject to the rigors of both the sea and the land. It has four distinct physical subdivisions based on the amount of exposure each gets -- the spray zone, and the high, middle, and lower intertidal zones. Each subzone has a characteristic and distinct biological community.
Click on each of the zones below to see pictures of life within that zone and to read a description of the zone itself, then answer the questions below.
The spray zone is perhaps more a part of the land than the ocean. It is submerged only during rare, very high tides or severe storms, but is repeatedly wetted by splashing waves and wind-blown spray.
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||Barnacles||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||Snail||Sea Stars and Anemones|
The lower intertidal zone is exposed only during the lowest spring tides.
|Anemones||Red Algae||Dungeness Crab||Sea Star and Sea Urchins||Kelp|