Estuaries also provide diverse habitats for wildlife and aquatic life, protect our communities against flooding, reduce pollution to waterways, and support local economies through commercial and recreational activities. Estuaries provide many different types of habitats, including shallow waters , open waters , marshes and wetlands , sandy beaches, mud flats and oyster reefs.
Thousands of species of wildlife and aquatic life, including fish , crabs, birds and mammals , depend on estuarine habitats for their survival. The wetlands that fringe estuaries perform extremely valuable functions that protect our waterways and communities. Wetlands act as natural buffers between the land and the water, guarding against erosion, flood waters and storm surges.
As water runs off the land, wetlands absorb and filter out pollution before it can make its way into the Bay.
Estuaries have important commercial value. The Chesapeake Bay watershed is characterized by rapidly flowing rivers discharging to the bay where tidal currents are weak. This creates the most stratified or least mixed type of estuary as classified by water circulation - a salt-wedge.
Fresh water, which is less dense than salt water floats on top of the salt water as it is pushed out to sea by the rivers. A sharp boundary with limited mixing is characteristic of salt wedge estuaries. The location of the wedge boundary varies with weather and tidal conditions.
Estuaries are fragile ecosystems that are very susceptible to disturbances both natural and those created by man. In the United States the ecology of estuaries has been severely damaged by man.
Diverting fresh water from tributaries for irrigation and drinking water supplies changes flow, quantity of fresh water entering the estuary, and impacts the balance within the ecology. Excess nutrients and sediment from sewage treatment plants, farm fields and animal pastures, urban and suburban run off from roads and landscaping can cause eutrophication. As the ecosystem of estuaries declines, species die out, coastlines experience excessive erosion by wind, tidal action and ice.
It is going to take knowledge, effort and resources wealth in all forms to restore the Chesapeake Bay. No comments:. Bald eagles , for instance, build two-ton treetop nests near the water, while brook trout depend on the shade of streamside trees to cool their underwater habitat.
Forests also support the economies of watershed states. Forestry is the second largest industry in the Pennsylvania and Virginia and the fifth largest in Maryland. Its waterfowl. Close to one million ducks, geese and swans spend their winters on the Bay.
Its seafood. The Bay produces about million pounds of seafood each year. Striped bass and Atlantic menhaden are also important catches for commercial markets. Its people. The Bay watershed is home to more than 17 million people, with , moving into the watershed each year. There are watermen, fishermen and farmers. There are hikers, bikers and boaters.
There are teachers, beach-goers and seafood-eaters. And many of them work to restore the natural resources in the watershed. Whether you take a tip from us to make Bay-friendly changes at home or attend an event to clean up your local waterway, you, too, can help restore the Bay—and celebrate National Estuaries Day! Learn more here. Great thumbnail sketch of this great bay. West of Elmira it turns south, forms the Grand Canyon of Pennsylvania, then widens as it flows past Harrisburg.
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