Streams and rivers provide a unique habitat for plants and animals due to flowing water that is well-oxygenated and cooler than still bodies of water like ponds and lakes. Trees lining stream banks help shade the water and provide nutrients from fallen leaves while aquatic insects break down leaves for food. Over time, erosion can cause trees to fall into streams, creating shelter for aquatic creatures.

1. Who Lives in a Stream or River Habitat?
Most of Earth is covered by water, but very little of it is freshwater.
Freshwater is an important natural resource that many living things need
to survive. But plants and animals, like river otters, need special
adaptations to live in stream and river habitats.
A stream or a river is a long body of moving water. Trees often line
the river or stream bank helping to shade the running water and keep
water temperatures much colder than a pond or lake. Rivers and
streams rarely freeze because the water is flowing all the time.
As the flowing water bubbles and gurgles over rocks and logs in the
water oxygen is infused into the water. Running water has a lot more
oxygen in it than still water!

2. The creatures that live in streams and rivers need more oxygen than the
creatures that live in a pond or marsh. Trout like cool, running water
with lots of oxygen, so they live in rivers or streams. Bass like warmer,
still water with less oxygen in it. Bass like ponds or lakes.
Plants help rivers and streams in several ways. The shade from the
trees keeps the water cool. Fallen leaves from the plants overhanging the
water introduce nutrients into the underwater food chain.
Many aquatic insects help to shred the fallen leaves into small pieces
of food for themselves or other small organisms. Those organisms
become food for larger aquatic organisms and so on.
Eventually, the trees growing along a river or stream bank will start
to topple because the moving water is slowly eroding soil away from
their roots. When those trees lose their “foot-hold” they will fall across

3. and into the water. The trunk and branches create wonderful habitat
for lots of small creatures that need shelter underwater.
Pond and lake habitats have mostly still, quiet water. Because there
are fewer trees shading these habitats the water is usually warmer. Ponds
and lakes can freeze during the winter since the water doesn’t move.
And calm water has less oxygen in it. Plants and animals that live in or
near a pond or lake have their own special adaptations for those
particular habitats.