Rivers
By Grace Taylor
Introduction
Rivers are almost everywhere. Rivers are in moderate climate. One place you
can not find rivers is a desert. The desert is dry and hot and the river is wet and cool.
The Ohio River begins in Philadelphia, Pennsylvania where the Allegheny and
Monongahela Rivers meet. The Ohio River is 981 miles of flowing water. It empties
into the Mississippi River at Cairo, Illinois. The Mississippi River is only 322 miles
long. Rivers can flow in any direction. The Ohio River flows mainly southward.
Rivers are full of different biotic and abiotic things.
Living and Non-living River Elements
You can find many biotic and abiotic elements in a river. Mostly, there are
just fish and plants. A common plant is algae. Algae is a simple organism. It lives in
lakes, rivers, and ponds. Sometimes, it lives on trees or rocks. A plant that is not
commonly known is Water Hyacinth. It grows in tropical regions and floats in lakes,
rivers and swamps. It’s not all plants though. There are plenty of animals in a river.
One type of fish is a Buffalo Fish. Actually, it’s 3 types of fish. They live in fresh-water
from Canada to Guatemala. Buffalo is not the only name of fish that applies to more
than one type. In fact, Goby is the name of 2,000 types of fish. It’s not just the fish
and plants home. There are Beavers and Musk Turtles too. There are also River
Otters and Harlequin Ducks. There are some things you wouldn’t think of like the
fact some Manatees spend winter in rivers. There are a lot of biotic things but there
are abiotic things too. Some of these abiotic things are water, earth, and rocks. The
river is home to many biotic and abiotic things.
Food Chain, Food Web, and Energy Sources in a River
A food web and a food chain effect biotic and abiotic elements in a river. At the bottom
of the food chain you have the plants. Snails eat a plant called Elodea. A minnow will eat
the Snail. Then, a minnow will be eaten by Salmon or Rainbow Trout. Rainbow Trout
also eat Caddis-fly Larvae. Salmon also eat Caddis-fly Larvae. Bacteria eats the remains
of Salmon. The simple organism of Algae is eaten by Caddis-fly Larvae. Energy is passed
through the bodies of different elements. From the producer- a plant – to the primary
consumer- like the snail – to the secondary consumer- like the minnow – to the
decomposer- like the salmon. The salmon goes and the bacteria decomposes it. If you
have ever wondered where a river gets it’s energy, it comes from a spring. Rivers start at
the top of a mountain as a springs. They then turn into streams and flow down the
mountain. The stream goes into the river. There are other forms of energy though.
Algae is a producer of energy, just not for a river itself. Algae produces energy for things
inside the river. Biotic and abiotic elements depend on each other for survival.
Threats to the River
The rivers of the world have many threats. Humans are one of the greatest threats.
Humans throw in trash and fish eat the trash. When one fish dies, less fish can be
produced. A way to help would be to go along the river bank and pick up trash in
shallow water. Sometimes, when you have a drink and you are by a river you spill some
of it. It can be considered pollution because it is ruining the water. Fish can’t live with
the pollution. A way to help is to make sure you don’t spill anything in. Another threat
are dams some times. Dams can sometimes be considered a threat because they block
the flow of water. It doesn’t effect the fish, but after a while the river might dry up.
There are plenty of threats to the ecosystem that can put it out of balance.
Interdependent Relationships in a River
Interdependent relationships help an ecosystem survive. Interdependent relationships
are where one organism depends on another for survival. One example of an
interdependent relationship is decomposers and producers. Decomposers depend on
producers for energy and nutrition. So, bacteria depends on algae because algae is a
producer and bacteria is a decomposer. Also, some fish depend on Water Fleas for
nutrition. The nutrition goes from the Water Flea to the fish that eats them. Another
interdependent relationship you can find in a river is plants and fish. The plants provide
shelter for the fish. If you take the plants away then the fish don’t have any shelter. If
you take Water Fleas away then the fish don’t have any food or nutrition. If you take
producers away then the decomposers don’t have any energy. If you take any one part
of the ecosystem away, the whole ecosystem will be effected. Some interdependent
relationships go in a circle. Take the producer algae for example, it will go to the primary
consumer, to the secondary consumer, to the decomposer, then back into the dirt. Then
the plant of algae can use it as nutrition. Biotic and abiotic elements of a river effect
each other in many ways.