Rivers

Habitat code: 415

Photo: KMD

Salmon
Oncorhynchus sp.
Photo: KMD		 Distribution and Habitat:
Salmon are born in streams and die in streams. They spend most of their lives in the ocean growing in size until they find their way back to their place of birth, spawn (lay eggs) and die.

Diet:
Aquatic invertebrates, smaller fish.

Interesting fact:
Not all salmon swim out to see after they are born. Some will stay in lakes and rivers for months to years. Pacific Northwest Indians have a legend about the importance of salmon.


Pacific giant salamander
Dicamptodon tenebrosus
Code: DITE
Photo: BL		 Distribution and Habitat:
It is found in moist forests on the rocky shores of mountain lakes and in or near cold streams.

Diet:
It feeds on small insects and invertebrates.

Interesting fact:
This salamander is capable of climbing as high as 8 feet into trees, logs and bushes. The bite of this salamander can break the skin.


Grizzly Bear
Ursus horribilis
Photo: KMD		 Distribution and Habitat:
Grizzly bears are found in the northern western states of the U.S., Canada and Alaska. They need wide open areas and are frequently found along rivers feeding on fish.

Diet:
They are omnivores eating salmon, small mammals, plants, roots and berries.

Interesting fact:
The large hump on their shoulder is a muscle. Their coats can vary from light brown to very dark brown. The largest of the grizzlies are found on Kodiak Island and are called Kodiaks.


City
Photo: JM

Interesting fact:
Cities use rivers for sources of electrical power, transportation, recreation and drinking water. This area was once an estuary with salmon runs in the river (right side of the picture).


Zebra Mussels
Dreissena polymorpha
Photo: BZ		 Distribution and Habitat:
A new invader of North American fresh surface waters, zebra mussels were introduced into Europe from their native habitat in the Black, Caspian and Aral Sea basins during the late 1700's. Ships from overseas probably carried the mussel in freshwater ballast which was discharged into the Great Lakes. It was first discovered there in June, 1988. Extensive colonies of up to 40,000 individuals per square meter were reported the next year.

Zebra mussels are fingernail-size clams with yellowish or brownish shells marked with wavy bands. Their larvae are too small to be seen, but they live for weeks in any water left in your boat. As zebra mussels grow, they form clumps that damage your boat, kill native clams, foul beaches with stinky razor-sharp shells, and clog water intake pipes.

Diet:
Zebra mussels are filter feeders. They feed by filtering particles of food as it passes over their gills.

Interesting fact:
Unlike all other freshwater mussels and clams, it releases sperm and eggs into the water, thus creating large colonies. Great care must be taken to not transport these mollusks between streams and lakes because of the ecological turmoil their are causing and millions of dollars of damage to human structures. To learn more the National Biological Inventory has information on their web site, which is listed in our Internet references.