considerably threatened, some even endangered. However, there is a reason for hope. These significant population segments of Steelhead Trout include: 1. Southern California Endangered 2. California Central Valley Threatened 3. Central California Coast Threatened 4. Lower Columbia River Threatened 5. Middle Columbia River Threatened 6. Northern California Endangered 7. Puget Sound Threatened 8. Snake River Basin Threatened 9. South-Central California Coast Vulnerable 10. Upper Columbia River Threatened 11. Willamette River Threatened 12. Middle Columbia River Experimental Population —(National Oceanic and Atmospheric Administration, US Department of Commerce) Conservation in these 12 key population centers for Steelhead Trout is crucial for their survival. The three ecological niche factors of Steelhead Trout include "habitat availability, access to spawning grounds, and the survival of the oceanic and freshwater life-stages" (Fulton). Steelhead Trout occupy a significant role in their endemic environment as their livelihood is highly contingent on water quality and pristine natural environment. Although not considered a keystone species, Steelhead Trout satisfy a crucial ecological role in their natural environment not only as an indicator species for habitat quality but also as a primary food source for predatory mammals and scavengers, including humans, alike. Because several conditions could determine the ecological success of Steelhead Trout populations, including external conditions related to human encroachment and pollution, Steelhead Trout populations in areas with concentrated human populations have largely struggled. Correlated with a decrease in Steelhead Trout numbers is also a decreased habitat quality in these urbanized areas. The human story is uniquely intertwined with steelhead because this specialized trout species occupies immense cultural significance in American natural history. Furthermore, the prospects of this species' survival are highly contingent on our conservation efforts and mitigation techniques. Freshwater rainbow trout forms have been introduced into the Great Lakes and migrate into tributaries to spawn. These trout are frequently, though incorrectly, referred to as steelhead, as they are non-anadromous. In Tasmania, commercially propagated steelhead are called Ocean Trout. Importance of water temperature The temperature of the water Steelhead swim in is crucial for their development and survival. Salmonoids are considered "poikilotherms", which means that temperature influences their life events, such as spawning. Water temperature is one of the most important environmental influences on the salmonid biology. Temperature determines when the Steelhead will begin migrating upstream, the time they will spawn and the time the fry will hatch. The development of steelhead eggs are also dependent on a certain temperature