estuaries

What is estuary ?

 is a body of water formed wherefreshwater from rivers and streams flows into the ocean, mixing with the seawater. Estuaries and the lands surrounding them are places of transition from land to sea, and from freshwater to saltwater.

Importance of estuary

The sheltered waters of estuaries are home to countless plants and animals that like to live in water that is part fresh and part salty. 

Estuaries protect water quality by filtering out dirt and pollution. In addition, estuaries and the land surrounding them are places where people live, sail, fish, swim, and bird watch. As a result, estuaries are often the centers of our coastal communities.

Estuaries are one of the most productive ecosystems in the world, so there is a great diversity of animals and plants that live there.

Plant that grows in estuary

Smooth cordgrass

Smooth cordgrass is one of the most common forms of marsh vegetation found in Rhode Island salt marshes and is a vital plant species in the estuary

Sea lavender

Also known as Limonium nashii, sea lavender grows during the summer months and is at full bloom in August. The plant grows to be about 12 inches and consists of small oval-shaped leaves. These plants are farthest away from the water in estuary biomes.

Spike grass

Spike grass, also known as salt grass and scientifically known as Distichlis spicata, is a short grass species that grows near and around marshland. It is the most common type of grass along the shoreline of estuaries.

Animals that grows in estuary

Great egret

The great egret is a large heron which, as an adult, has entirely white plumage with contrasting black feet and long, black legs. Colour is added by its bright yellow bill, tipped with black, and the greenish-yellow area between the bill and the eye .

Hermit crab

Hermit crabs are known to be one of the free swimming aquamarine saltwater animals, that somewhat resembles a snail’s structure, minus the slow paced move. It’s protective armor or hermit crab shells serves two purposes both beneficial for survival and protection

Native littleneck clamp

The range of this species is from Alaska to Mexico. It is similar in size and appearance to the Manila littleneck. It is a medium-size clam, oval to round in shape. The external surface is marked with concentric rings and radiating ridges which produce a cross-hatched appearance.

Estuaries in the philippines

River-estuary of Lobo, Batangas

Estuaries in the world

Hudson River Estuary

New York City, with a population of over eight million people, is located at the mouth of the Hudson River Estuary which stretches 153 miles inland from the Atlantic Ocean and includes a wide range of wetland habitats. Home to more than 200 species of fish, the Hudson River Estuary serves as a nursery ground for sturgeon, striped bass, and American shad. It also supports an abundance of other river-dependent wildlife, especially birds. (Photo: Stanne/NYSDEC)

 Old Woman Creek National Estuarine Research Reserve.

 It is located on the south-central shore of Lake Erie in Erie County, Ohio, three miles east of Huron. It is the only "Great Lakes-type" freshwater estuary in the National Estuarine Research Reserve System, and features freshwater marshes, swamp forests, a barrier beach, an upland forest, and a portion of nearshore Lake Erie. 

Chesapeake bay

The Chesapeake Bay is the largest estuary in the United States and is one of the most productive bodies of water in the world.

The Chesapeake watershed spans 64,000 squares miles, covering parts of six states — Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the District of Columbia. Over 17 million people live in this area.

Problems and issues

Pathogens

Pathogens are disease-producing organisms such as bacteria and viruses. The sources of these organisms are human waste, pasture runoff, and waste products of marsh animals such as nutria and birds.

Hydrologic modification

Hydrologic modification is considered the “linchpin” problem of the basins, indicating that all other problems revolve around, and are often affected by it. When we build levees, dredge canals, or cut through natural ridges, the natural flow of water is changed.

In other cases, it can result in changed salinity of water bodies. As a result, fresh marsh can be changed to a more “salt tolerant” type. In more extreme cases, marsh can be converted to open water.

Habitat loss

What is known about the rate of habitat conversion, and ultimately land loss in the coastal areas of the Barataria and Terrebonne basins, is that it is alarmingly high. Studies through 1978 showed that over 11,500 acres of land a year were being lost as it slowly converted to open water due to subsidence or other factors.

Eutrophication

When too many nutrients, such as phosphorus and nitrogen, are in the water, a condition known as eutrophication occurs. The process begins with an accelerated growth of algae with the end result being that oxygen in the water is depleted as plant matter decays, killing fish and shellfish.

Toxic substance

Water, animal tissue, and sediment testing have identified a variety of toxic substances in the basins. Some of the substances are known cancer-causing agents while others affect reproduction. When some animals consume contaminated food, the toxic concentration is magnified.

Change in living resource

Approximately 735 species of birds, finfish, shellfish, reptiles, amphibians, and mammals spend all or part of their life cycle in the estuary. Several of the species are either categorized as threatened or endangered. 

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