General sketch-map of a tidal plain, showing the typical tripartition in supratidal
zones. The most apparent character of the area is the development of tidal channels, affecting mainly the intertidal zone
. In this case, the tidal flat is protected seaward by a beach barrier
, but in many cases (low-energy waves
and longshore currents
) the tidal flats may directly pass into a shallow marine environment.
Mudflats or mud flats, also known as tidal flats, are coastal wetlands that form when mud is deposited by tides or rivers. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of estuarine silts, clays and marine animal detritus. Most of the sediment within a mudflat is within the intertidal zone, and thus the flat is submerged and exposed approximately twice daily.
In the past tidal flats were considered unhealthy, economically unimportant areas and were often dredged and developed into agricultural land. Several especially shallow mudflat areas, such as the Wadden Sea, are now popular among those practising the sport of mudflat hiking.
On the Baltic Sea coast of Germany in places, mudflats are exposed not by tidal action, but by wind-action driving water away from the shallows into the sea. These wind-affected mudflats are called windwatts in German.
Tidal flats, along with intertidal salt marshes and mangrove forests, are important ecosystems. They usually support a large population of wildlife, and are a key habitat that allows tens of millions of migratory shorebirds to migrate from breeding sites in the northern hemisphere to non-breeding areas in the southern hemisphere. They are often of vital importance to migratory birds, as well as certain species of crabs, mollusks and fish. In the United Kingdom mudflats have been classified as a Biodiversity Action Plan priority habitat.
The maintenance of mudflats is important in preventing coastal erosion. However, mudflats worldwide are under threat from predicted sea level rises, land claims for development, dredging due to shipping purposes, and chemical pollution.
Mudflat sediment deposits are focused into the intertidal zone which is composed of a barren zone, marsh and salt pan. Within these areas are various ratios of sand and mud that make up the sedimentary layers. The associated growth of coastal sediment deposits can be attributed to rates of subsidence along with rates of deposition (example: silt transported via river) and changes in sea level.
Barren zones extend from the lowest portion of the intertidal zone to the marsh areas. Beginning in close proximity to the tidal bars, sand dominated layers are prominent and become increasingly muddy throughout the tidal channels. Common bedding types include laminated sand, ripple bedding, and bay mud. Bioturbation also has a strong presence in barren zones.
Marshes contain an abundance of herbaceous plants while the sediment layers consist of thin sand and mud layers. Mudcracks are a common as well as wavy bedding planes. Marshes are also the origins of coal/peat layers because of the abundant decaying plant life.
Salt pans can be distinguished in that they contain thinly laminated layers of clayey silt. The main source of the silt comes from rivers. Dried up mud along with wind erosion forms silt dunes. When flooding, rain or tides come in, the dried sediment is then re-distributed.
Selected example areas
- Arcachon Bay, France
- Banc d'Arguin, Mauritania
- Great Rann of Kutch, India
- Belhaven, East Lothian Scotland, United Kingdom
- Bridgwater Bay and Morecambe Bay, United Kingdom
- Cape Cod Bay, Massachusetts, United States
- Cook Inlet, Alaska, United States
- Lindisfarne Island, England, United Kingdom
- Minas Basin, Nova Scotia, Canada
- Padilla Bay, Washington, United States
- Plymouth Bay, Massachusetts, United States
- Port of Tacoma, Washington, United States
- Skagit Bay, Washington
- Snettisham Norfolk England, United Kingdom
- Wadden Sea: Netherlands, Germany, Denmark
- West coast of Andros Island, Bahamas
- Yellow Sea, China, Korea
- Moreton Bay, Queensland, Australia
Air Date: 7.6.2012 Reporter: Natalie Travis, Photographer: Eric Stratton.
Dirty Video Warning: Alaska Mudflats!
An incredible day at the mudflats near Cook Inlet and on the outskirts of Anchorage, Alaska. The mudflats are sort of like Alaska's version of quicksand...it...
(Korean Culture 100) Mudflats, a Beautiful Ocean Field Created by Humans and Nature_한국의 갯벌
Mudflats, a Beautiful Ocean Field Created by Humans and Nature Part 1. Watercolor Picture of Time Painted on Mud The morning sun shines on the calm mudflats....
Invincible Youth 2 | 청춘불패 2 - Ep.2 : Surviving at the mudflat!
Surviving at the mudflat! Spcial mission, catch octopus~ ---------------------------------------------------------------------------------- Subscribe KBS W...
What goes on beneath that broad glassy surface while the water's in? Find out with this underwater time-lapse of the marine mudflats!
Mud Flat Girl - Performance Art - Part 1
Beta edit, an 18 year old girl ventures out onto some mud flats.
Mud flat under Incheon Bridge 인천대교 주변 갯벌, 밀물과 새떼
2013년 10월9일 오후 촬영.
Killdeer Chick Foraging on a Mud Flat
http://thebuffleheadbirder.com/ - a Killdeer chick searches for worms and small insects in the muddy shore along a pond. This little bird proved itself to be...
Mudflat Studio, Somerville, Massachusetts
http://www.laricciamediaproductions.com Mudflat Studio in Somerville Massachusetts, Wayne Fuerst, Teacher demonstrates pottery making at Grand Opening 9-10-1...
Redfish on mud flat...
A barge had passed and sucked all the water from this mud flat. As the water returns, you can see a redfish wallowing in the mud. Jason Bryant.
The Daily News of Newburyport
Mon, 10 Mar 2014 08:47:13 -0700
The river laps up to the back of the building, and small boats sit in the mudflat. Today, all that area is grassy park. Even with all this activity, the neighborhoods on the waterfront were for the most part the lowest rung on the city's ladder of ...
New Zealand Herald
Thu, 06 Mar 2014 20:07:30 -0800
Rocky reef to mudflat - and everything between. And that's before you even take the plunge. The snorkeller glides over great areas of 'biogenic' seafloor composed almost entirely of the hard parts of animals that used to live on the seafloor and in the ...
Thu, 06 Mar 2014 04:56:15 -0800
One acre of the property, clearly visible from overhead photos, has already turned into a mudflat. “Mangroves are the heartbeat of Tampa Bay,” said Roy Lewis III, president of Lewis Environmental Services, the Riverview company that designed the ...
Thu, 06 Mar 2014 07:00:00 -0800
Last year at Boysen, Poison Creek's inlet was a thawing mudflat; one filled with secrets among the clumps of dead grasses and in the cups of slushy water between the hummocks. Now it shone glassily, both alluring and possibly treacherous. We hemmed ...
Tue, 04 Mar 2014 18:03:45 -0800
The driver tried to proceed quietly, but as he pulled out of the forest and into the open, most of the ducks dabbling within easy range of my camera lens skeedaddled to the far end of the pond, leaving only undeterred greater yellowlegs to comb a ...
Fri, 07 Mar 2014 07:56:15 -0800
The Sesti Tgawaals Unit is an exposed mudflat with the water about 150 yards out from the center of the cove. Miller Island Unit. The Miller Island Unit is located 6 miles south and west of Klamath Falls. The Miller Island Unit is open to hunting on ...
Sun, 02 Mar 2014 10:40:28 -0800
The tidal drop in Bristol Bay reduces the Nushagak River to a mudflat. PHOTOGRAPH BY MICHAEL MELFORD, NATIONAL GEOGRAPHIC. The tidal drop in Bristol Bay temporarily turns Alaska's Nushagak River into a mudflat. There's still a chance the mine ...
Fri, 07 Mar 2014 07:56:15 -0800
A middle option would keep the inlet where it is and would re-capture acres of mudflat habitat. The anticipated price tag of the middle option is between $50 million and $64 million. Conservancy officials are working on securing the money needed for ...
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