 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
Pollution of Aquatic Systems
A large concern at many of the National Parks is the pollution of our watershed and aquatic systems. Previous mining in Whiskeytown has resulted in large amounts of heavy metal contamination in creeks, and the creation of numerous pits, old roads and trails. Logging in the area has affected how water 
drains into the creeks changing growth patterns of plants and washing large amounts of granite and sedimentation into the water. All this sediment and creek alteration decreases habitat for many fish and prevents insects, which the fish feed on, from surviving. A history of logging in the upper Redwood Creek watershed has left a similar legacy of sediment in the stream, with negative impacts on fish and other aquatic life. Scientists can track these effects by studying the physical features of a stream or the sensitive residents that inhabit it.
The Caddisfly
If you have ever gone exploring in a freshwater stream, turning over rocks, looking for insects, you definitely have encountered the caddisfly and its case. The larval form of this insect (often referred to as a macroinvertebrate) carries its home around with it as it goes from rock to rock shredding plant material or other debris found in the water. Their portable cases, which can be made from rocks, leaves, or sand, are held together by silk, and act to protect and camouflage the insect from predators. Caddisflies are a scientist's best friend because they are one way to tell whether or not a stream is healthy. Caddisflies are sensitive to pollution, so when a stream is contaminated you won’t find them. Insects sensitive to negative changes in their habitat are often referred to as “Indicator Species.” Indicator species are used to give us early warnings of pollution and contamination of our water systems. Caddisflies do best in fast flowing streams that are cool and rich in oxygen. Because caddisflies are sensitive to pollutants and sediment buildup in a stream, they will not survive unless their habitat is healthy. Without caddisflies, certain fish such as juvenile salmon have little to eat, negatively impacting their populations. When scientists are studying streams or mountain lakes they sample macroinvertebrates to give them an idea of the quality of the water. If a stream or lake is determined unhealthy, scientists will try to restore the water to a healthy state so the caddisflies and other organisms can survive and reproduce.
Changes are being made to improve the health of water systems in the national parks. In 2000, the McCormick-Saeltzer Dam on Clear Creek in Whiskeytown was removed and greatly improved the habitat for spring-run Chinook salmon and steelhead trout. Whiskeytown is still working towards improving its water through a watershed restoration plan aimed at reducing sediment in its streams. Redwood NSP also has a large watershed restoration program in which over 150 miles of roads have been removed benefiting three listed salmonids and old growth redwoods.
Crater Lake NP | Oregon Caves NM | Redwood NP | Lassen Volcanic NP
Whiskeytown NRA | Lava Beds NM | NPS Klamath Network | SOU Home
An Outreach and Education Project made possible by the National Park Service, Klamath Network Inventory and Monitoring and Southern Oregon University
