Freshwater Ecosystems

• Every river is part of a larger system-a watershed, which is the land drained by a river and its tributaries.

• Rivers are large natural streams of water flowing in channels and emptying into larger bodies of water.

• This diagram shows some common characteristics of a river system.

• Every river is different, however, so not all rivers may look exactly like this illustration.

What Lives in a River?• Organisms have adapted to fast moving

water.• Current speed determines what lives in a

river or stream.

1. Producers such as algae & moss cling to rocks

2. Consumers: insect larvae hide under rocks

3. Tadpoles use suction disks

Parts of a River

1. RIVER SOURCE, also called the headwaters, is the beginning of a river.

2. Often located in mountains, the source may be fed by an under- ground spring, or by runoff from rain, snowmelt, or glacial melt.

Watershed1. A watershed boundary,

also called a drainage divide, marks the outer- most limit of a watershed.

2. A watershed is a tract of land drained by a river and its tributaries.

3. Anything that affects a watershed may eventually impact its tributaries and river as well as the water body at the mouth of the river.

4. People's actions within a watershed can affect the overall quality of its rivers.

Water from this entire area that drains off of the land enters the Mobile River Basin. The water comes from streams and other rivers across Alabama, Mississippi and Georgia.

Mobile River Watershed

DOG RIVER WATERSHED

Floodplain

1. A fully-developed floodplain is relatively flat land stretching from either side of a river, which may flood during heavy rain or snowmelt.

2. Built of materials deposited by a river, floodplain soil is often rich in nutrients and ideal for growing food.

Tributary

• A tributary is a smaller stream or river that joins a larger stream or main river.

Main River and Meander

1. The main river is the primary channel and course of a river.

2. A meander is a loop in a river channel. A meandering river winds back and forth, rather than following a straight course.

Mouth of a River

1. The river mouth is the place where a river flows into a larger body of water, such as another river, a lake, or an ocean.

Wetlands

1. Wetlands are low-lying areas saturated with water for long enough periods to support vegetation adapted to wet conditions.

2. Wetlands help maintain river quality by filtering out pollutants and sediments, and regulating nutrient flow.

3. Swamps are an example of a wetland.

Delta1. A delta is a landform that

is created at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river.

2. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river.

3. Over long periods of time, this deposition builds the characteristic geographic pattern of a river delta.

Mobile-Tensaw Delta

• The delta is characterized by a large number of distributary rivers, streams, bayous, and creeks which form a maze of waterways.

• The delta and adjacent Mobile Bay Estuary comprise one of the largest wetland ecosystems in the United States

Fauna of the Delta

• 126 species of fish • 40 species of mammals, including black bears, wild pigs

and deer • 69 species of reptiles such as alligators and the rare red-

bellied turtle • 30 species of amphibians • 500 species of plants, including swamp lilies, cardinal

flowers, butterfly weed, green-fly orchids and the tiny-leaved buckthorn, one of the rarest shrubs in the United States

• More than 300 species of birds, including eagles, ospreys, pelicans, herons, kites, owls, warblers, vireos, wrens, egrets and a variety of woodpeckers, including the Pileated woodpecker, which can grow as long as 19 inches and is the largest woodpecker in North America

Problems Facing Rivers: Pollution

1. 2 types of pollution that affect rivers:

a. point source pollution

b. nonpoint source pollution

Point Source Pollution1. Point source pollution is “any single identifiable

source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack”[1].

2. Factories and sewage treatment plants are two common types of point sources. Some factories discharge their effluents directly into a waterbody.

3. Others treat it themselves before it is released, and still others send their wastes to sewage treatment plants for treatment.

4. Sewage treatment plants treat human wastes and send the treated effluent to a stream or river.

Nonpoint source pollution NPS1. Nonpoint source (NPS) pollution, unlike pollution from industrial and

sewage treatment plants, comes from many diffuse sources. 2. NPS pollution is caused by rainfall or snowmelt moving over and

through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water.

3. These pollutants include:4. Excess fertilizers, herbicides, and insecticides from agricultural

lands and residential areas;5. Oil, grease, and toxic chemicals from urban runoff and energy

production;6. Sediment from improperly managed construction sites, crop and

forest lands, and eroding streambanks;7. Salt from irrigation practices and acid drainage from abandoned

mines;8. Bacteria and nutrients from livestock, pet wastes, and faulty

septicsystems;9. Atmospheric deposition and hydromodification are also sources of

nonpoint source pollution.

Rivers in our Area

• Dog River

• Mobile River

• Tensaw River

• Fowl River

• Fish River- Baldwin County

• Dog River Watershed Map

Mobile River Basin

• Mobile River