Salmon Stream Habitat
Salmon have a unique life cycle! They are called anadromous
, which means that they live in salt water and then migrate up freshwater streams to spawn and lay their eggs. Because stream habitats are so important to salmon survival, we need to take care of the waters that run through our communities.
Salmon are important for a number of reasons. They provide nutrients for the forest ecosystems around the streams where they spawn. In the ocean they have a huge role in the food chain by eating smaller fish and being eaten by large marine animals like seals and orcas! For indigenous peoples they are a source of food and of cultural and spiritual importance. And lastly, for everyone else who calls the Pacific Northwest home, they provide food, industry, tourism, recreation, and a sense of amazement.
So, what does the ideal salmon stream habitat look like? Below are the ingredients for what we call a Dream Stream:
Salmon like cooler water temperatures and trees help shade the water. Trees also hold the stream bank in place with their roots. The area of trees and shrubs around a stream is called the riparian zone
. For salmon- bigger riparian zones are better.
Rocky Stream Bed
Salmon protect their eggs by burying them in gravel nests. Larger rocks create riffles that put oxygen into the water which fish need to take into their gills.
Fallen logs create hiding places and slow down water flow so that salmon can rest.
Murky water is a sign that the stream bank is eroding or breaking away. It also makes it difficult for salmon to navigate.
Curvy Stream Shape
A stream with lots of bends and turns slows down the flow of water and makes it easier for migrating salmon to swim upstream. A straight channel speeds up water flow and increases stream bank erosion, making water murkier and difficult to swim against.
Salmon become more sensitive to environmental stress when pollution is high. This can include litter, but even more concerning is chemicals like nitrogen fertilizers that run off from lawns and farms.
Practice what you learned
For each of the images below, list what attributes of each stream are good and bad for salmon health.
Draw a Dream Stream!
Now that you know what salmon like, use the art supplies in your home to draw a salmon dream stream! Alternatively, you can draw the opposite- a nightmare stream that has all the things that salmon do not like. Happy drawing!