Rainbow Trout

Depending on what phase of their life history strategy they are in, steelhead live in freshwater rivers and streams, estuaries and marine environments. Steelhead trout occupy freshwater streams or lakes during spawning and then migrate back through brackish water to the open ocean to live during their adult non-spawning phase of their life cycle. Steelhead trout spend most of the year in estuaries or open ocean and only return to fresh water to spawn.

Steelhead trout feed on a variety of aquatic and terrestrial invertebrates and small fish. They normally feed on zooplankton when they are young and as they mature begin to include fish eggs, crustaceans, mollusks, small fish and even mice in their diet. 

 There have been reports of steelhead trout weighing up to 55 pounds.  

Steelhead normally reach lengths of 18 to 24 inches, but have been reported reaching lengths of 45 inches.

Often steelhead trout are more silver in color and grow larger than rainbow trout that remain in freshwater. The only way to confirm a fish is a steelhead trout is by look at its scales or by analyzing the chemical composition of its otoliths, or ear bones. 

Steelhead trout are the anadromous form of rainbow trout. Rainbow trout can remain in freshwater their entire lives, or they can migrate to the ocean and then return to freshwater to spawn. These fish are known as steelhead trout. The only way to confirm a fish is a steelhead trout is by look at its scales or by analyzing the chemical composition of its otoliths (ear bones). 

Steelhead trout are one of the top five recreational fish species in North America, and are culturally important to Native American tribes. Steelhead trout have been known to jump 11 feet into the air when climbing waterfalls on migration runs, and can go from zero to 25 miles per hour in one second!  The oldest steelhead trout ever captured was 11 years old, and there have been reports of steelhead weighing up to 55 pounds!   

Unlike their salmon cousins, steelhead trout are iteroparous, meaning they can spawn multiple times during their life.  Steelhead return to the estuary or ocean between spawns, but return to their natal stream, or the stream where they were born, each time they spawn. Some steelhead spawn in consecutive years, while other steelhead may skip a year between spawning cycles.   

Steelhead trout have very unique life cycles, and their migration patterns are not fully understood yet. Some steelhead trout may spend several years in the ocean before returning to spawn, while others may only spend a few months in salt water before returning. Additionally, some juvenile steelhead trout may spend up to a year in freshwater before out-migrating to the ocean, while others may leave freshwater within months of hatching. 

Migration Behavior 

Steelhead trout are migratory rainbow trout. These migratory rainbow trout are born in freshwater and then migrate to the ocean for their adult lives and return to freshwater to reproduce.