Littoral zone
The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore.
Biologically, the ready availability of water enables a greater variety of plant and animal life, and particularly the formation of extensive wetlands.
In oceanography and marine biology, the idea of the littoral zone is extended roughly to the edge of the continental shelf.
Organisms that live here must cope with exposure to fresh water from rain, cold, heat, dryness and predation by land animals and seabirds.
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 barnacles.
This results in high primary production and makes the sublittoral zone the location of the majority of sea life.
[4] Littoral areas of ponds and lakes are typically better oxygenated, structurally more complex, and afford more abundant and diverse food resources than do profundal sediments.
[5] In freshwater situations, the littoral zone is the nearshore habitat where photosynthetically active radiation penetrates to the lake bottom in sufficient quantities to support photosynthesis.
[1] 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.
[9][10] Many of the animals in lakes and rivers are dependent upon the wetlands of littoral zones, since the rooted plants provide habitat and food.
Fish can be negatively affected by docks and retaining walls which remove breeding habitat in shallow water.
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.
[12][13] Hence, over time, dams can reduce the area of wetland from a broad littoral zone to a narrow band of vegetation.
For the purposes of naval operations, the US Navy divides the littoral zone in the ways shown on the diagram at the top of this article.
