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STREAM ECOLOGY. By Maggie Bell-McKinnon, biologist Washington Department of Ecology Email: MBEL461@ecy.wa.gov. Why Should We Care About Streams?. Wildlife drink water out of streams. We like to fish and swim in streams.
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STREAM ECOLOGY By Maggie Bell-McKinnon, biologist Washington Department of Ecology Email: MBEL461@ecy.wa.gov
Fish and other aquatic animals need good water quality for their homes and for their food.
Stream Discharge - is the total amount (volume) of water flowing in the stream.It is important to know how much water is flowing in a stream because it affects many things about a stream, for example: * Salmon need slower flowing areas of a stream to lay their eggs. * Other aquatic animals (like macroinvertebrates) and algae can’t live in a stream that has water moving too fast.
Stream Discharge – how to measure Stream discharge is measured by multiplying the area of the stream by its velocity. Stream discharge is measured in cubic feet per second (cfs).
A Pretend Stream Stream Discharge = Area (A) x Velocity (V) Depth Area (A) = Depth x Width Width
A Real Stream 1 10 3 4 5 6 7 8 9 Stream Area = the area of box 1+box 2+box 3+ box 4+box 5+box 6+box 7+box 8+box 9+box 10
Embeddedness • Embeddedness refers to how much the rocks (gravel, cobble, and boulders) are surrounded by, covered, or sunken into the silt, sand, or mud of the stream bottom.
Embeddedness • Generally, as rocks become embedded, fewer living spaces are available to macroinvertebrates and fish for shelter, spawning and egg incubation.
Riparian Zone • The area between the stream and the land away from the stream. • Riparian comes from the Latin word, ripa, which means river bank. • Because the riparian zone can flood, the vegetation that grows there must be able to tolerate having its roots get wet occasionally.
Riparian zones are important to a stream because: • They filter pollutants and prevent them from entering the stream
Riparian zones are important to a stream because: • They prevent the streambank from eroding or wearing away.
Riparian zones are important to a stream because: • They supply shade to the stream
Riparian zones are important to a stream because: • They provide shelter and food for animals that live in or near the stream
Examples of Riparian Vegetation • In a healthy riparian zone, there are typically three layers of vegetation that occur: • Tall trees • Shorter trees and shrubs • Flowering plants and ferns
Food Web The Sun
Food Web Black Fly Larvae
Food Web Caddis Fly Larvae
Food Web Caddis Fly Larvae
Food Web Water Louse
Food Web Water Strider
Water Quality Parameters Dissolved Oxygen • Oxygen in the water comes from the air/ atmosphere and the aquatic plants (through photosynthesis).
Water Quality Parameters Dissolved Oxygen • Aquatic organisms – plants and animals – need to breathe oxygen, just like people.
Water Quality Parameters Dissolved Oxygen • Dissolved oxygen levels change throughout the day based on water temperature and photosynthetic activity.
Water Quality Parameters Temperature • Stream temperature controls how plants and animals live. • Warm water contains less dissolved oxygen than cool water.
Water Quality Parameters Temperature • Young salmon need temperatures of around 9°Centigrade; adult salmon need water that’s 12°Centigrade.
Water Quality Parameters pH A pH measurement tells us whether a stream is acidic or alkaline. pH values range from 0 to 14; values from 0 to 7 are considered acidic, 7 is neutral and above 7 is considered alkaline or basic. The pH of a stream is determined by what kind of rocks the stream flows over and sometimes by humans.
