World Library  
Flag as Inappropriate
Email this Article

Intertidal zone

 

Intertidal zone

Bancao Beach at Low Tide showing Intertidal Zone from about 200 m from the beach

The intertidal zone, also known as the foreshore and seashore and sometimes referred to as the littoral zone, is the area that is above water at low tide and under water at high tide (in other words, the area between tide marks). This area can include many different types of habitats, with many types of animals, such as starfish, sea urchins, and numerous species of coral. The well-known area also includes steep rocky cliffs, sandy beaches, or wetlands (e.g., vast mudflats). The area can be a narrow strip, as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion.

  • Enchanted Learning
  • Enyclopædia Britannica
  • The Intertidal ZoneWatch the online documentary

External links

  1. ^ a b

References

See also

Gallery

The Intertidal Zone was used as a title for Stephen Hillenburg's old comic strip. The comic strip starred "Bob The Sponge", who would later go on to become SpongeBob SquarePants.

Other media

In Greece, according to the L. 2971/01, the foreshore zone is defined as the area of the coast which might be reached by the maximum climbing of the waves on the coast (maximum wave run-up on the coast) in their maximum capacity (maximum referring to the “usually maximum winter waves” and of course not to exceptional cases, such as tsunamis etc.). The foreshore zone, apart of the exceptions of the law, is public, and permanent constructions are not allowed on it.

In the UK, the foreshore is generally deemed to be owned by the Crown although there are notable exceptions, especially what are termed several fisheries which can be historic deeds to title, dating back to King John's time or earlier, and the Udal Law, which applies generally in Orkney and Shetland.

For privately owned beaches in the United States, some states such as Massachusetts use the low water mark as the dividing line between the property of the State and that of the beach owner. Other states such as California use the high-water mark.

As with the dry sand part of a beach, legal and political disputes can arise over the ownership and use of the foreshore. One recent example is the New Zealand foreshore and seabed controversy. In legal discussions the foreshore is often referred to as the wet-sand area.

Legal issues

Since the foreshore is alternately covered by the sea and exposed to the air, organisms living in this environment must have adaptions for both wet and dry conditions. Hazards include being smashed or carried away by rough waves, exposure to dangerously high temperatures, and desiccation. Typical inhabitants of the intertidal rocky shore include urchins, sea anemones, barnacles, chitons, crabs, isopods, mussels, starfish, and many marine gastropod molluscs such as limpets and whelks.

The intertidal region is an important model system for the study of ecology, especially on wave-swept rocky shores. The region contains a high diversity of species, and the zonation created by the tides causes species ranges to be compressed into very narrow bands. This makes it relatively simple to study species across their entire cross-shore range, something that can be extremely difficult in, for instance, terrestrial habitats that can stretch thousands of kilometres. Communities on wave-swept shores also have high turnover due to disturbance, so it is possible to watch ecological succession over years rather than decades.

A California tide pool in the low tide zone

Ecology

This subregion is mostly submerged - it is only exposed at the point of low tide and for a longer period of time during extremely low tides. This area is teeming with life; the most notable difference with this subregion to the other three is that there is much more marine vegetation, especially abalone, sea anemones, brown seaweed, chitons, crabs, green algae, hydroids, isopods, limpets, mussels, nudibranchs, sculpin, sea cucumber, sea lettuce, sea palms, starfish, sea urchins, shrimp, snails, sponges, surf grass, tube worms, and whelks. Creatures in this area can grow to larger sizes because there is more available energy in the localized ecosystem. Also, marine vegetation can grow to much greater sizes than in the other three intertidal subregions due to the better water coverage. The water is shallow enough to allow plenty of light to reach the vegetation to allow substantial photosynthetic activity, and the salinity is at almost normal levels. This area is also protected from large predators such as fish because of the wave action and the relatively shallow water.

Low tide zone (lower littoral)

Depending on the substratum and topography of the shore, additional features may be noticed. On rocky shores, tide pools form in depressions that fill with water as the tide rises. Under certain conditions, such as those at Morecambe Bay, quicksand may form.

Marine biologists divide the intertidal region into three zones (low, middle, and high), based on the overall average exposure of the zone. The low intertidal zone, which borders on the shallow subtidal zone, is only exposed to air at the lowest of low tides and is primarily marine in character. The mid intertidal zone is regularly exposed and submerged by average tides. The high intertidal zone is only covered by the highest of the high tides, and spends much of its time as terrestrial habitat. The high intertidal zone borders on the splash zone (the region above the highest still-tide level, but which receives wave splash). On shores exposed to heavy wave action, the intertidal zone will be influenced by waves, as the spray from breaking waves will extend the intertidal zone.

A rock, seen at low tide, exhibiting typical intertidal zonation, Kalaloch, Washington, western USA.
Tide pools at Pillar Point showing zonation on the edge of the rock ledge

Zonation

Contents

  • Zonation 1
  • Low tide zone (lower littoral) 2
  • Ecology 3
  • Legal issues 4
  • Other media 5
  • Gallery 6
  • See also 7
  • References 8
  • External links 9

A typical rocky shore can be divided into a spray zone or splash zone (also known as the supratidal zone), which is above the spring high-tide line and is covered by water only during storms, and an intertidal zone, which lies between the high and low tidal extremes. Along most shores, the intertidal zone can be clearly separated into the following subzones: high tide zone, middle tide zone, and low tide zone. The intertidal zone is one of a number of marine biomes or habitats, including estuaries, neritic, surface and deep zones.

, and the littoral zone is a prime example. ecologies which is actively moved to the zone by tides. Edges of habitats, in this case land and sea, are themselves often significant sea supplied in high volume on a regular basis from the nutrients in the littoral zone allows the use of Adaptation. mangroves in the littoral zone are ameliorated by local features and larger plants such as microclimates to near freezing in colder climates. Some sun range can be anything from very hot with full temperature can dislodge residents from the littoral zone. With the intertidal zone's high exposure to the sun, the waves with drying between tidal inundations. The action of salt and dry saline to highly rain but varies from fresh with tides is available regularly with the Water [1] The intertidal zone is also home to many several species which cut across different taxa including Porifera, Annelids, Coelenterates, Mollusks, Crustaceans, Arthropods, and etc.[1]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.