Freshwater Biomes
Summary
Many of the earth’s habitats are under water and are called aquatic habitats. Salinity, depth, rate of
flow, and amount of dissolved oxygen are factors that determine the types of organisms that live in
different aquatic biomes.
Standing-water ecosystems include lakes, ponds, marches, swamps and bogs. Phytoplankton are
often the main producers in deep standing water. Wetlands are habitats where water and land come
together. Wetlands are a very important part of the biosphere that are in particular danger from
human activities.
All bodies of flowing fresh water are considered streams. Stream organisms are adapted to the rate of
flow in the stream. The course of a stream changes naturally over time, creating more “edge” as it
flows. Human activity has diverted many stream habitats to provide water and energy, but this
process has destroyed many of these important ecosystems. There are many ecological solutions to
provide water and energy to human populations without destroying these habitats. These solutions
include rainwater collection, grey water systems, swales and wetland restoration projects. All of
these solutions are simple and easy, which means that everyone can experiment wherever they are.
Concept Review: Write a complete response to each of the following.
1. Explain how a stream’s flow rate affects its food web.
2. List four abiotic factors that determine the types of organisms in aquatic systems.
3. How does depth affect the food web of a lake ecosystem?
4. Describe four beneficial functions of wetlands?
5. Why does the reproductive behavior of salmon make the fish vulnerable to changes in
habitat?
6. Certain farming and irrigation practices increase the amount of sediments that are carried by
streams. How might these practices affect the ecosystem of a stream? What are some possible
solutions to this type of agriculture?