The intertidal zone is an extreme ecosystem because it constantly experiences drastic changes. It is located on marine coastlines, including rocky shores and sandy beaches. The intertidal zone experiences two different states: one at low tide when it is exposed to the air and the other at high tide when it is submerged in seawater. The zone is completely submerged by the tide once or twice every day. This ecosystem is rife with research opportunities for marine researchers like National Geographic grantee Swapnale Gole, who studies the behavior of sea anemones, crustaceans, and fish in the intertidal zones of the Andaman Islands in India.
Organisms that live in the intertidal zone tend to form their own communities across the zone’s elevation gradient. Some species live further up the shore and closer to the high tide line, while others live further down the shore, closer the low tide line. Anything living in the intertidal zone must be able to survive changes in moisture, temperature, and salinity and withstand strong waves. Intertidal zones of rocky shorelines host sea stars, snails, seaweed, algae, and crabs. Barnacles, mussels, and kelps can survive in this environment by anchoring themselves to the rocks. Barnacles and mussels can also hold seawater in their closed shells to keep from drying out during low tide. Intertidal zones richer in sediments are filled with different species of clams, sand dollars, and worms.
At rocky shorelines, tide pools can form in holes, cracks, or crevices where seawater collects as the tide goes out. Organisms that cannot normally survive low tide conditions, like sea stars, shrimp, or fish, can take refuge in these pools. Sandy shores provide sediments in which organisms bury themselves to stay cool and moist during low tide. Where a species lives within the intertidal zone depends on its tolerance of underwater and above-water conditions. The presence of predators and species that compete for the same space and food also impact where an organism will be found. Continue reading from National Geographic
On the shore between high and low tide lies the intertidal zone, where land and sea meet. The intertidal zone is underwater during high tide and exposed to air during low tide. The animals and plants that live in this zone must cope with being submerged in water and exposed to the air during different times of day. Many species of worms, snails, clams, oysters, mussels and seastars make the intertidal zone their home. Rocky shores and sandy beaches fall within the intertidal zone. The motion of high tide and low tide creates four zones within the intertidal zone where different animals and plants live.
Spray Zone
The spray zone is the upper part of the beach that occasionally gets splashed, but never gets covered by the ocean. This zone is more a part of the land than the ocean. Plants and animals in the spray zone have adapted to living exposed to the air, sun, rain and even frost.
High Intertidal Zone
The high intertidal zone is flooded during the peaks of the once or twice daily high tides, and out of the water for long stretches of time in between. Here plants and animals are used to living above the water surface.
Mid Intertidal Zone
The middle intertidal zone is generally submerged, except for a period during the turn of low tide. More plants and animals live here because they are not exposed to drying conditions for too long.
Low Intertidal Zone
The lower intertidal zone is exposed to air for only a short period of time at low tide. Life here is adapted to conditions underwater. Continue reading from National Park Service
The intertidal or littoral zone maintains a balance between the land and the sea. It provides a home to specially adapted marine plants and animals. Those organisms, in turn, serve as food for many other animals.
The intertidal zone also staves off erosion caused by storms. Oyster reefs are one such example of a protective feature. This helps protect the structures built by people.
The intertidal zone is also an important indicator for climate change on marine organisms. Continue reading from Sciencing
