The River Habitat
By GreenWorks Assistant Producer, Dave Beste
t is not
uncommon to be walking near a river and see a fish swimming
among the reeds or notice songbirds singing on a nearby tree,
but what does often go unrecognized is the fragile nature
of the river habitat. Several species of birds, fish, amphibians,
insects, and mammals use rivers as their home, which is why
it is not only important to keep the rivers healthy, but to
understand how they have protected themselves for millions
ne of the
most important ways the river filters out potential pollutants
is through riparian forest buffers. A riparian forest is simply
the area of land next to the river that maintains the transition
from land to the body of water. They exist not solely near rivers,
but also creeks, streams, and any other water source imaginable.
It is these floodplain areas that often produce the vegetation
needed to help sustain the river and the life that depends on
it. The primary function of the riparian forest is to act as
a buffer and prohibit the often ill-effects of agriculture and
urban development from harming the river. Because of the diverse
area that the riparian forest encompasses it is able to support
a much larger and more diverse population than other habitats.
on the riverbank are useful in trapping runoff pollutants and
a strong root system in a shoreline forest can prove to be instrumental
in preventing erosion. It is not infrequent for these habitats
to be destroyed by unknowing homeowners manicuring their lawns
or simply runoff pollution. Through a process called "denitrification"
the roots of trees can take up pollutants and prevent them from
ever reaching the river, as well as, processing the harmful
nitrates into harmless nitrogen gas.
hese often unnoticed actions along the water's edge are necessary
in providing a healthy habitat for those who live in the river.
The tall grass and trees provide a habitat where many species
can find shade from an unreasonably hot day and are useful in
maintaining a cooler water temperature. The riparian forest
also provides food for those predators looking for a meal, whether
it is insects or plant life.
forest offers many diverse habitats to many species of animals.
It is home to migratory birds, herons, eagles, turtles, otters,
ducks, and numerous others. Not to mention the several types
of migratory fish, which use the banks of rivers for hiding
and feeding along their journey.
along rivers also provide a welcoming home for many birds and
wildlife. Existing as a more isolated and self-contained world
the species that live here often need a more undisturbed environment.
As an example, Wade Island in Harrisburg, Pennsylvania exists
as the only place in the state where one can find the Great
Egret. In an area surrounded by islands the Great Egret has
made only Wade Island it's home. It is constantly being threatened,
however, by proposals to raise the water level at a nearby dam.
Even a minimal change in depth could drastically change the
habitat and balance that the island has created.
major disruption to the river habitat over the years has been
the creation of dams, levees, and other man-made buildings that
block the proper flow of the river and keep several species
of fish from reaching their desired spawning grounds. These
structures blocking the waterway have helped cause a severe
decline in certain fish populations, such as the American shad,
according to the Chesapeake Bay Program.
he combination of riparian forests, bay grasses, wetlands, islands,
and numerous other habitats have helped to provide healthy rivers
across the nation. But these same rivers have also had to withstand
constant polluting and abuse.
a result the Army Corps of Engineers and hundreds of watershed
and environmental organizations across the nation have begun
restoration activities to combat the effects of river habitat
interference and work to realize the natural conditions of the
river. Due to a change over the years in public values there
has been less demand for dams and other river altering structures
and new solutions are being considered "like relocation
and land acquisition." (American Rivers). A new public
sentiment of conservation has led to changes in policy and heightened
awareness as to the importance of our rivers.
References and Links:
Office of Water
Rough Terrain- Wade Island
Chesapeake Bay Program
River Habitat Protection and Streambank Restoration
Rivers Habitat Partnership
See past topics of In the Flow here!