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'{{short description|Part of a sea, lake or river that is close to the shore}} {{Redirect|Littoral}} {{for|the transfer of business or IT processes into a nearby country|Nearshoring}} {{ocean habitat topics|image=Littoral Zones.jpg|caption=Different disciplines and agencies divide the littoral zone into different subregions, according to how they want to view the zone.}} The '''littoral zone''' or '''nearshore''' is the part of a [[sea]], [[lake]], or [[river]] that is close to the [[shore]]. In coastal environments, the littoral zone extends from the [[high water mark]], which is rarely inundated, to shoreline areas that are permanently [[underwater|submerged]]. The littoral zone always includes this [[intertidal zone]], and the terms are often used interchangeably. However, the meaning of ''littoral zone'' can extend well beyond the intertidal zone. The term has no single definition. What is regarded as the full extent of the littoral zone, and the way the littoral zone is divided into subregions, varies in different contexts. (Lakes and rivers have their own definitions.) The use of the term also varies from one part of the world to another, and between different disciplines. For example, military commanders speak of the littoral in ways that are quite different from [[marine biology|marine biologists]]. The adjacency of water gives a number of distinctive characteristics to littoral regions. The [[erosion|erosive]] power of water results in particular types of [[landform]]s, such as [[sand dune]]s, and [[estuary|estuaries]]. The natural movement of the littoral along the coast is called the [[littoral drift]]. Biologically, the ready availability of water enables a greater variety of plant and animal life, and particularly the formation of extensive [[wetlands]]. In addition, the additional local [[humidity]] due to evaporation usually creates a [[microclimate]] supporting unique types of organisms. The word ''littoral'' may be used both as a [[noun]] and as an [[adjective]]. It derives from the [[Latin language|Latin]] noun ''litus, litoris'', meaning "shore". (The doubled ''tt'' is a late-medieval innovation, and the word is sometimes seen in the more classical-looking spelling ''litoral''.) ==In oceanography and marine biology== [[File:Olympic Coast National Marine Sanctuary.jpg|thumb|The littoral zone of an ocean is the area close to the shore and extending out to the edge of the continental shelf.]] [[File:Portugal 20040711 027.jpg|thumb|right|The [[intertidal zone]] of a beach is also part of the littoral zone.]] [[File:Klamath river estuary.jpg|thumb|right|[[Estuary|Estuaries]] are also in the littoral zone.]] {{wiktionary|littoral}} {{wiktionary|circumlittoral|infralittoral|sublittoral|supralittoral}} In [[oceanography]] and [[marine biology]], the idea of the littoral zone is extended roughly to the edge of the [[continental shelf]]. Starting from the shoreline, the littoral zone begins at the spray region just above the high tide mark. From here, it moves to the intertidal region between the high and low water marks, and then out as far as the edge of the [[continental shelf]]. These three subregions are called, in order, the [[Littoral zone#Supralittoral zone|supralittoral zone]], the [[Littoral zone#Eublittoral zone|eulittoral zone]] and the [[Littoral zone#Sublittoral zone|sublittoral zone]]. ===Supralittoral zone=== {{main|Supralittoral zone}} The ''supralittoral zone'' (also called as the ''splash'', ''spray'' or ''supratidal zone'') is the area above the spring high tide line that is regularly splashed, but not submerged by ocean water. Seawater penetrates these elevated areas only during storms with high tides. Organisms,that live here, must cope with exposure to fresh water from rain, cold, heat, dryness and [[predation]] by land animals and seabirds. At the top of this area, patches of dark [[lichen]]s can appear as crusts on rocks. Some types of [[Common periwinkle|periwinkles]], [[Neritidae]] and detritus feeding [[Isopod]]a commonly inhabit the lower supralittoral.<ref name="Yip and Madl">Yip and Madl</ref> ===Eulittoral zone=== {{see also|Intertidal zone}} The ''eulittoral zone'' (also called as the ''midlittoral'' or ''mediolittoral zone'') is the ''intertidal zone'', which is also known as the ''foreshore''. It extends from the spring high tide line, which is rarely inundated, to the spring low tide line, which is rarely not inundated. It is alternately exposed and submerged,once or twice daily.The organisms living here must be able to withstand the varying conditions of temperature,light, salinity etc. Inspite of this,the productivity is high in this zone. The wave action and turbulence of recurring tides shape and reform cliffs, gaps and caves, offering a huge range of habitats for sedentary organisms. Protected rocky shorelines usually show a narrow almost homogenous eulittoral strip, often marked by the presence of [[barnacle]]s. Exposed sites show a wider extension and are often divided into further zones. For more on this, see [[intertidal ecology]]. ===Sublittoral zone=== {{see also|Neritic zone}} The ''sublittoral zone'' starts immediately below the eulittoral zone. This zone is permanently covered with seawater and is approximately equivalent to the [[neritic zone]]. In [[physical oceanography]], the sublittoral zone refers to coastal regions with significant tidal flows and energy dissipation, including non-linear flows, [[internal wave]]s, river outflows and oceanic fronts. In practice, this typically extends to the edge of the [[continental shelf]], with depths around 200 meters. In marine biology, the sublittoral zone refers to the areas, where sunlight reaches the ocean floor, that is, where the water is never so deep as to take it out of the [[photic zone]]. This results in high [[primary production]] and makes the sublittoral zone the location of the majority of sea life. As in physical oceanography, this zone typically extends to the edge of the [[continental shelf]]. The benthic zone in the sublittoral is much more stable than in the intertidal zone; temperature, water pressure, and the amount of sunlight remain fairly constant. Sublittoral corals do not have to deal with as much change as intertidal corals. [[Coral|Corals]] can live in both zones, but they are more common in the sublittoral zone. Within the sublittoral, marine biologists also identify the following: *The '''infralittoral zone''' is the algal dominated zone, which may extend to five metres below the low water mark. *The '''circalittoral zone''' is the region beyond the infralittoral, that is, below the algal zone and dominated by [[Sessility (zoology)|sessile]] animals such as [[mussel]]s and [[oyster]]s. Shallower regions of the sublittoral zone, extending not far from the shore, are sometimes referred to as the '''subtidal zone'''. {{clear}} ==In freshwater ecosystems== [[File:Moon Lake shoreline - Riding Mountain National Park.JPG|thumb|right|Shoreline of a lake with nearly unvegetated littoral zone]] In freshwater situations, littoral zones occur on the edge of large lakes and rivers, often with extensive areas of [[wetland]]. Hence, they are sometimes referred to as fringing wetlands. Here, the effects of tides are minimal, so other definitions of "littoral" are used. For example, the [[Minnesota Department of Natural Resources]] defines littoral as that portion of the lake that is less than 15&nbsp;[[foot (length)|feet]] in depth.<ref>{{cite web|url=http://www.dnr.state.mn.us/lakefind/surveys.html#littoral|title=Fisheries lake surveys| accessdate =|website = Minnesota Department of Natural Resources}}</ref> The littoral zone may form a narrow or broad fringing wetland, with extensive areas of aquatic plants sorted by their tolerance to different water depths. Typically, four zones are recognized, from higher to lower on the shore: wooded wetland, [[wet meadow]], [[marsh]] and [[aquatic vegetation]].<ref name = keddy2>Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. Chapter 2.</ref> The relative areas of these four types depends not only on the profile of the shoreline, but upon past water levels. The area of wet meadow is particularly dependent upon past water levels;<ref name="Keddy, P.A 2010">Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK.</ref> in general, the area of wet meadows along lakes and rivers increases with natural water level fluctuations.<ref>Wilcox, D.A, Thompson, T.A., Booth, R.K. and Nicholas, J.R. 2007. Lake-level variability and water availability in the Great Lakes. USGS Circular 1311. 25 p.</ref><ref>Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p.</ref> Many of the animals in lakes and rivers are dependent upon the wetlands of littoral zones, since the rooted plants provide habitat and food. Hence, a large and productive littoral zone is considered an important characteristic of a healthy lake or river.<ref name="Keddy, P.A 2010"/> Littoral zones are at particular risk for two reasons. First, human settlement is often attracted to shorelines, and settlement often disrupts breeding habitats for littoral zone species. For example, many turtles are killed on roads when they leave the water to lay their eggs in upland sites. Fish can be negatively affected by docks and retaining walls which remove breeding habitat in shallow water. Some shoreline communities even deliberately try to remove wetlands since they may interfere with activities like swimming. Overall, the presence of human settlement has a demonstrated negative impact upon adjoining wetlands.<ref>{{cite journal|last1=Houlahan|first1=J. E.|last2=Keddy|first2=P. A.|last3=Makkay|first3=K.|last4=Findlay|first4=C. S.|title=The effects of adjacent land use on wetland species richness and community composition|journal=Wetlands|date=2006|volume=26|issue=1|pages=79–96|doi=10.1672/0277-5212(2006)26[79:TEOALU]2.0.CO;2}}</ref> An equally serious problem is the tendency to stabilize lake or river levels with dams. Dams removed the spring flood which carries nutrients into littoral zones, and reduces the natural fluctuation of water levels upon which many wetland plants and animals depend.<ref>Middleton, B. A. (ed.) 2002. Flood Pulsing in Wetlands: Restoring the Natural Hydrological Balance. John Wiley, New York</ref><ref>Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497. Chapter 2.</ref> Hence, over time, dams can reduce the area of wetland from a broad littoral zone to a narrow band of vegetation. Marshes and wet meadows are at particular risk. ==Other definitions== For the purposes of naval operations, the [[United States Navy]] divides the littoral zone in the ways shown on the diagram at the top of this article. The [[United States Army Corps of Engineers]] and [[United States Environmental Protection Agency|Environmental Protection Agency]] have their own definitions, and these have legal implications. ==See also== {{div col|colwidth=22em}} * [[Ballantine Scale]] * [[Benthic zone]] * [[Coastal fish]] * [[Foreshore]] * [[Intertidal zone]] * [[Limnetic zone]] * [[Littoral combat ship]] * [[Littoral drift]] * [[Littoral series]] * [[Littoral warfare]] * [[Marine debris]] * [[Neritic zone]] * [[Profundal zone]] * [[Shingle beach]] {{div col end}} ==Notes== {{reflist|30em}} ==References== {{Refbegin}} * Haslett, Simon K (2001) ''Coastal Systems.'' Routledge. {{ISBN|978-0-415-21302-8}} * Mann, Kenneth Henry (2000) [https://books.google.com/books?id=y4OIojDxtzsC&pg=PA179 ''Ecology of Coastal Waters''] Blackwell Publishing. {{ISBN|978-0-86542-550-7}} * Yip, Maricela and Madl, Pierre (1999) [http://biophysics.sbg.ac.at/rovigno/rovigno3.htm ''Littoral''] [[University of Salzburg]]. {{Refend}} {{physical oceanography|expanded=other}} {{coastal geography}} {{DEFAULTSORT:Littoral Zone}} [[Category:Aquatic biomes]] [[Category:Marine biology]] [[Category:Aquatic ecology]] [[Category:Habitats]] [[Category:Coasts]] [[Category:Fisheries science]] [[Category:Coastal geography]] [[Category:Oceanographical terminology]] [[Category:Limnology]] [[Category:Oceanography]]'