About Small Streams
Small Streams represent one of the most important
ecosystems in the world. They play an important role in water transfer and
provide a home for countless species of animals and plants. The streams that
I will discuss in this project are referred
to as first-order or headwater streams. These are small streams that receive
water solely from precipitation and thus have no feeder streams or other water
inflow. In addition, 
these
streams may be seasonal, and dont support many large predators. The result
is a very diverse environment that supports very high diversity of plant and
animal species. Unfortunately, because they receive direct runoff from the
land, small streams some of the environments most severely effected by habitat
disturbance and runoff (Hoffman et al. 1995). In addition to direct runoff
of pollution, these streams suffer sedimentation, deoxygenation, and erosion
from anthropogenic disturbance. In order to determine the effects of disturbance
on stream-dwelling organisms, it is necessary to develop standardized techniques
for analyzing habitat disturbance within small watersheds. Here I propose
a system that uses Geographic Information Systems (GIS) to categorize and
quantify habitat disturbance within small watersheds.
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Undisturbed
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Disturbed
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Undisturbed
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Disturbed
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Animals that rely on small-stream environments:
photo credit: J.D. Willson, Mike Dorcas, Eric Stine, John
White, and K. Crandall (permission pending)
Aquatic Insects - many types of aquatic insects
are found only in moving water. Generally, smaller streams have fewer and smaller
fish, resulting in high populations of aquatic insects. Stream environments
also provide a much wider variety of habitats that still water, generally resulting
in higher invertebrate diversity.
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Mayfly |
Crayfish - Crayfish are very common in many streams
Fish - Although fish are generally more common
in larger streams, minnows are common in small streams. In addition, small,
cool streams are vital habitat for young trout and salmon, species highly revered
by anglers.
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Brook Trout are native to many
small streams in eastern U.S. and have been widely introduced elsewhere |
Reptiles and Amphibians:
Salamanders - are the most common vertebrates
in many streams (particularly in the southeast and pacific northwest). Many
species of salamanders are only found in small stream environments where they
are safe from fish. Because they have permeable skin and inhabit both aquatic
and terrestrial habitats, salamanders are particularly susceptible to habitat
disturbance and pollution.
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The Hellbender (Cryptobranchus
alleganiensis), reaching 29", is the largest amphibian in the
U.S. It inhabits rocky streams in the Appalachian Mountains.
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One of the most beautiful salamanders
in the U.S., the Red Salamander (Pseudotriton Ruber), is
common in small streams in the Eastern U.S.
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Blue Ridge Two-Lined Salamander
(Eurycea wilderae)
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Blackbelly Salamander (Desmognathus
Quadramaculatus)
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Southern Dusky Salamander (Desmognathus
auriculatus)
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Dusky Salamanders are abundant
throughout the eastern U.S.
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Turtles - Many species of turtle utilize small
streams.
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Eastern Mud Turtle (Kinosternon
subrubrum)
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Spiny Softshell (Apalone
spinifera)
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Snakes - While many snakes inhabit stream habitats,
watersnakes, garter and ribbon snakes, and crayfish snakes are particularly
common.
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Queen Snake (Regina
septemvittata)
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Ribbon Snake (Thamnophis
sauritus)
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Garter Snake (Thamnophis
sirtalis)
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Northern Water Snake (Nerodia
sipedon)
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Other Reptiles and Amphibians - Many species of
frogs, toads, and lizards also use small-stream habitats.
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Northern Cricket Frog (Acris
crepitans)
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Pickerel Frog (Rana
palustris)
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Many other animals, especially mammals and birds utilize
small-stream environments.
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