Freshwater Ecosystem Services
Purify Drinking Water
http://www.esa.org/ecoservices/comm/body.comm.fact.wate.html
Water Purification is one of the many services provided by ecosystems. Pollutants such as
metals, viruses, oils, excess nutrients, and sediment are processed and filtered out as water
moves through wetland areas, forests, and riparian zones. This purification process provides
clean drinking water and water suitable for industrial uses, recreation, and wildlife habitat.
How Natural Water Purification Works
Water purification depends on filtration and absorption by soil particles and living
organisms in the water and soil. Human activities that compact soil, contaminate the
water or alter the composition of organisms, degrade the purification process and can
accelerate movement of unfiltered water through the system and into our water
supplies.
• Wetlands. Wetlands can remove 20 to 60% of metals in the water, trap and retain 80
to 90% of sediment from runoff and eliminate 70 to 90% of entering nitrogen. Many
types of plants are specially adapted to different kinds of wetlands, and a large
percentage of the nation's imperiled plants and animals depend on wetlands for at
least part of their life cycle.
• Riparian Forests. Riparian (streamside) forests act as "living filters" that intercept and
absorb sediments, and store and transform excess nutrients and pollutants carried in
runoff from adjacent lands. They can reduce the nitrogen concentration in water runoff
and floodwater by up to 90%, and can reduce phosphorous by as much as 50%.
• Microorganisms. Microorganisms are the natural chemical engineers of the
ecosystem. Bacteria and other organisms utilize or break down nutrients, metals, and
other chemical contaminants in the water.
• Constructed Wetlands. Constructed wetlands mimic some of the filtration power of
natural systems. They can be cost efficient for small communities but can not replace
natural wetlands, and may not provide the many other wetland services (such as flood
control and fish and wildlife habitat).
Protect river, stream, and shores from erosion and Mitigate (lessen the impact)
drought and floods
http://water.epa.gov/type/oceb/fact5.cfm
What Is an Estuary and What Does It Do?
An estuary is a partially enclosed body of water formed where freshwater from rivers, streams, and
groundwater flows to the ocean, mixing with the salty seawater. Although influenced by the winds
and tides, estuaries are protected from the full force of ocean waves, winds, and storms by the reefs,
barrier islands, or fingers of land, mud, or sand that define an estuary's seaward boundary.
Estuaries come in all shapes and sizes and go by many different names. They are often known as
bays, lagoons, harbors, inlets, or sounds. Whatever the name or type, estuaries provide valuable
functions.
•
• They are critical to the survival of tens of
thousands of birds, mammals, fish, and
other wildlife. Many different habitat types
are found in and around estuaries,
including shallow open waters, freshwater
and salt marshes, sandy beaches, mud and
sand flats, rocky shores, oyster reefs,
mangrove forests, river deltas, tidal pools,
sea grass beds, and wooded swamps.
• The wetlands bordering many estuaries perform valuable functions including water quality
and flood protection and water storage. Many upland areas drain to fresh and salt marshes,
which act as filters, removing pollution from runoff. Wetland plants and soils also act as a
natural buffer between the land and the ocean, absorbing floodwaters and dissipating
storm surges. Salt marsh grasses, mangrove trees, and other estuarine plants also prevent
erosion and stabilize the shoreline.
• They are a source of recreation, education, and aesthetic value. Boating, fishing, swimming,
windsurfing, and bird-watching are just a few of the many activities people enjoy in
estuaries.
• Estuaries have important commercial value. They serve as nursery grounds for two-thirds of
the nation's commercial fish and shellfish. Estuaries are also home to ports and marinas
that support shipping and other industrial activities.
Read the article on Freshwater Ecosystem Services and then complete the matching exercise and
questions to see what you know. Answer longer questions on the back.
_____ 1. Stream side forests that act as "living filters" that intercept and absorb sediments, and store
and transform excess nutrients and pollutants carried in runoff from adjacent lands.
_____2. Bacteria and other tiny organisms in this category utilize or break down nutrients, metals, and
other chemical contaminants in the water.
_____3. Vital area of swampy land that can remove 20 to 60% of metals in the water, trap and retain 80
to 90% of sediment from runoff and eliminate 70 to 90% of entering nitrogen.
_____4. A partially enclosed body of water that forms where freshwater meets the ocean. Sometimes
these areas are referred to as bays, sounds, harbors, or lagoons.
a. estuary b. wetlands c. riparian forests d. microorganisms e. purification
5. What three vital services do the wetland areas bordering estuaries supply?
6. Explain how wetland plants and soils act as natural buffers.
7. How do estuaries play a role in our economy?