Researched by Jordan P.
2000-01

• PURPOSE 
• HYPOTHESIS 
• EXPERIMENT DESIGN 
• MATERIALS 
• PROCEDURES 
• RESULTS 
• CONCLUSION 

• RESEARCH REPORT 
• BIBLIOGRAPHY 
• ABOUT THE RESEARCHER

• ACKNOWLEDGEMENTS

INTRODUCTION

Every stream and wetland is a vital part of the food chain and the chain of life. Fish, insects, birds and mammals all rely on streams to provide for them food and shelter. Streams are also a main water source for towns and cities. Streams often provide water for aquifers that people use. 
 

STREAMS AND WETLANDS
 

Each and every stream and wetland is a unique water system. Even different sections of streams vary. Certain things give these water systems their variety. These include the geographical location of the watershed, the geological composition of the stream and the riparian vegetation. The riparian zone is a belt of vegetation that lines the stream bank. The endless varieties of wetlands provide the opportunity for a number of different creatures to adapt to every niche of many water systems.
 

HEADWATERS AND UPPER REACHES
 

The headwater is the source of the stream or river. Many headwaters flow from springs at high elevations fed by ground water. Other headwaters flow from glaciers, marshes and snowmelts. Many streams in the Pacific Northwest flow from springs in the Cascade mountain range. 
A variety of plants and animals inhabit the upper reaches. Which are usually heavily forested with a variety of evergreens such as pines, firs and cedars. The terrestrial plants that overhang the stream provide food in the form of falling needles, cones, bark and debris for insects that inhabit the stream. The large objects feed certain insects called shredders that shred the food. It also provides food for collectors that collect small particles and predators.  Because of these large insects and the cool water with oxygen, the upper reaches of streams provide ideal habitat for many trout and salmon species. Other creatures that inhabit the stream riparian zone include bears, osprey, kingfishers, otters and giant salamanders. Many forest creatures often visit the stream to feed or drink. Huckleberry bushes evergreens and aspen occupy riparian vegetation. Very little human disturbance occurs in the upper reaches except for logging operations.
 

MID REACHES
 

Further downstream water flow increases widening the stream bank. As the stream grows further apart, over-hanging vegetation becomes scarce. This scarcity of overhanging vegetation allows the water to heat more quickly changing the environment of the stream. 
The heated water makes habitat less suitable for trout and salmon but creates a living environment for warm water species such as bass, northern pike minnow and catfish. The increased sunlight also provides suitable living conditions for aquatic plants such as algae. Primarily insects known as grazers feed on the algae. Collector insects also remain, as do predators. Tributaries flow into this portion of the river. Riparian creatures include great blue herons, beavers, ducks and crayfish. Plants include species such as cottonwoods, willows, red osier dogwood and water hemlock. Human activity also increases further downstream.  Human activity is often harmful especially in the cases of certain agricultural practices such as cattle farming. Cattle erode stream banks and eat riparian vegetation.  Also pesticides from farms kill insects that fish feed on. 
 

LOWER REACHES
 

The lower reaches of the stream are the widest part of the river. Here
the river has a much greater flow and many more tributaries empty into the water. Human development also increases in the proximity of the lower reaches. Towns and cities often line the banks the river. This increases pollution levels in the form of sewage, lawn pesticides and storm drains. Increased levels of human development also means less riparian habitat. More power needs force the development of dams or fossil fuel power plants that add additional stream or air pollution.
Insects in the river change to collectors that feed on detritus, fine particles of plants. The widening river has a warm temperature and the streambed is made of sediments from upstream. Many warm water fish live in this part of the river, as do many bottom feeders such as sturgeon and whitefish. Animals that inhabit this lower area vary from river to river but generally include great blue herons, ravens, squirrels, trout and raccoons. Riparian habitat consists of Oregon grape, dogwood and cottonwood. 
 

SALMON
 

Salmon are a species of fish that are related to trout. All salmon species belong to the genus oncorhynchus. They are anadromous meaning that they hatch in freshwater, migrate to the ocean then return to freshwater to spawn. There are 5 species of salmon in the Pacific Northwest they are pink (O. gorbuscha), sockeye (O. nerka), chum (O. keta), coho (O. kisutch) and chinook (O. tshwytscha). All species are also known by local names such as king, humpie and silver. There is also another salmon called Cherry salmon (O. masou) that live in East Asia. Steelheads also belong to the genus oncorhynchus but are just an anadromous form of steelhead. All salmon need clean; cool, fast flowing streams with insects and places for they’re young to live, though certain species of salmon use different niches of streams and rivers. 
 

LIFE CYCLE
 

All salmon hatch in freshwater. Salmon begin as eggs that were deposited earlier that fall by the parental fish. Redds are eggs nests that are made up of gravel. There are between one thousand to ten thousand eggs in every redd. 
Several months after the eggs were deposited they develop into alevins. Alevins look like small transparent fish and feed on large yolk sacs on their belly. The alevins remain in the redd for several more months. 
The young alevins develop into fry in the spring. The life of the young fry is more or less made up of hiding from predators such as herons, kingfishers and bass. They prey upon plankton and small aquatic insects. The fry stay in the stream from 1-3 years depending upon species. 

The fry are silvery and larger now and are called smolts. The smolts migrate downstream through tributaries from their natal stream. They face many dangerous encounters and predators. Dams block their passage and they fall prey to predators such as northern pike minnow and large mouth bass. They also face pollution downstream especially near major cities or urban developments. 
Once the fry reach an estuary they begin to change. Their bodies adapt to seawater as they feed on the rich wildlife that flourishes there. Different species spend different numbers of years at sea. Usually the largest spend the most time at sea and the smallest spend the least. Chinook that can reach up to 60 pounds usually spend 3-5 years at sea while pinks that only weigh 11 pounds spend only 2 years at sea. The fish face predators such as orcas, sea lions and fisherman. After several years at sea feeding on squid, plankton and small fish, the salmon re-enter freshwater directed by light, magnetic poles or chemicals. 
Once in freshwater the fish are guided to their native stream by chemicals in the water picked up by their olfactory lobe. The fish do not eat on their way to their natal stream instead live off fat from the ocean. Salmon on their upstream migration face a number of dangers and obstructions. Dams block the fish upstream migration, as do rapids. Bears, eagles and otters prey upon fish. 
Once the salmon return to their native stream they spawn. Some fish such as pinks and chum spawn near the ocean, Chinook spawn in large rivers, coho spawn in small streams while sockeye spawn in or near lakes. The salmon change appearance. Both males and females develop humps on their backs and males develop a kype or hooked jaw for fighting. The females dig a nest with their tail while males fight and jockey for position to spawn. The female releases her eggs and the male fish releases milt or sperm to fertilize them. After this the fish die although some steelhead live to spawn more times.
 

LOGGING
 

Logging is the practice of cutting trees for timber sales. Logging creates many problems for stream and riparian habitat. Soil and silt flows unfiltered into streams at the loss of trees, which trap the diluted water and control sediment flow into the stream. The loss of shade and food is also another product of logging. Trees provide a valuable food source for macro invertebrates in the form of leaves, cones, needles, bark and bits of detritus. With the loss of these things the insect population declines and creates a negative domino effect for the rest of the food chain. Loss of shade increases the water temperature beyond a suitable living environment for fish such as trout.
 

MINING
 

If mining occurs near the watershed it can be very harmful for the environment. Mining releases harmful chemicals such as copper. Mining if conducted in close proximity to a stream can release large amounts of sediments and polluted water. These pollutants carry far downstream.
 

IRRIGATION
 

Irrigation releases run-off from farmland and carries large amounts of silt and sediments from cultivated fields. If not properly used; irrigation can create sediment-choked waters in nearby streams, smothering fish eggs and warming water temperatures. This warming creates a desirable habitat for algae growth. Algae deplete oxygen levels in the water, not providing enough for fish or insects. Irrigation can also release high levels of nitrogen and phosphorous that can promote algae growth to an undesirable level.
 

CATTLE
 

Cattle if not properly controlled can cause considerable damage to the riparian environment. The cattle often erode stream banks and eat stream vegetation necessary for insect food and shade for fish. The erosion of banks allows sediments to flow directly into the stream and the loss of riparian vegetation allows sediments to flow uncontrolled. The feces of cattle can also enter the stream through rain flow and can promote uncontrollable growth of algae. Cattle also stomp salmon redds and stir up sediment in the streambed, smothering redds.
 

URBAN DEVELOPMENT
 

Urban sprawl can be very harmful to fish and to the watershed. Homes, offices and other buildings too close to stream and riparian boundaries eliminate riparian habitat. Development to close too the stream destroys possible riparian habitat and releases sediments into the water. Roads and parking lots with insufficient drainage’s and storm drainage’s can release polluted water and sediments into the watershed and also release chemicals. These chemicals kill insects and can even kill fish. Human disturbance of the watershed can stress animals and cause less reproduction. Human pollution also kills fish and their food. Human development also releases extra salts in the water creating a more saline environment for freshwater fish.
 

TURBIDITY
 

Turbidity is a measurement of the clarity of water. If water is clear then it has less sediment that cloud up the stream or river. If the water is dirty then the water has organic matter or sediments in it. Turbidity is measured in NTUs. The way turbidity is measured is by taking a vial of water and putting it in a turbidimeter, which sends a high, powered beam of light that refracts at a ninety-degree angle into a lens that reads the refraction of the particles. If there are more particles there will be more refraction and it will appear darker.
 

PHOSPHOROUS AND NITROGEN
 

Nitrogen and phosphorous are chemicals that are found in water. These chemical fertilizers come from nutrients that flow into streams. These nutrients include silt, sediments, dead bodies or even sewage. Both these chemicals spur the growth of underwater plants such as algae. Algae can be a hazardous plant if too many exist at one site. Nitrogen and phosphorous are tested by using a kit that traces water for them.
 

SUMMARY
 

 Streams provide habitat and food for an entire ecological system. The streams of the Pacific Northwest are inhabited by many different species such as salmon, bass, herons and otters. This ecological system is unique to the northwest but some of the species that inhabit the environment have been transported to different nations and states.

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 "EXTINCTION IS NOT AN OPTION," Governor’s Salmon Recovery Office. Pp. 1-7, November, 1999

Greenfield, David W. "Salmon," World Book Encyclopedia. 1998. Vol.17. Pp. 69-71

Larson, J.S." Wetlands," New York: International Waterfowl and Wetlands Bureau, 1991. Pp. 25-29

Mitchell, Mark K. and Stapp, William B. Field Manual for Water Quality Monitoring. Dubuque, Iowa: Kendall/Hunt Publishing, 1997. Pp.69-84

Nehlson, Willa, Williams, Jack, and Lichatowich, James. "Salmon Stocks at the Crossroads: Stocks at Risk from California, Oregon, Idaho, and Washington", American Fisheries Society.16: 2 pp. 4-1

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 "The state of Salmon report," Governors Salmon Board.  Pp. 2-21, December 2000

Trout. Harrisburg, Pa.: Stackpole Books, 1991. Pp. 29-36

Watch over Washington. "Turbidity". [Online] Available http://www.wa.gov/ecology/wq/wow/db/index.cqi?d=tools&e=7, January 3, 2001