of the water. The temperature steelhead prefer to spawn in range from . No salmonid species can survive in temperatures exceeding . Unfortunately, in California, there have been longer drier seasons than cold-wet seasons and that will cause an increase in California's river system temperatures. Parasites and pathogens With all the pesticides people put into their yards, all the agriculture that surrounds our water, many pollutants and pathogens enter our watersheds. This can cause numerous environmental factors affecting the organisms that reside in our fresh waters. With an increase in greenhouse gas and high CO2 levels, this can cause an algae bloom and warmer bodies of water. When pH levels are too high it can cause damage internally and externally which eventually kill the steelhead. An increase in water temperature makes Steelhead incapable of handling further stressors and makes them more susceptible to parasites and pathogens. These warmer waters magnify the biotic relationships and increase parasitism. A study was done to explore why Steelhead were experiencing lesions on their bodies in a river of West Virginia and the results showed a correlation of lesions on the fish when water is low, the pH levels were high. Dam installments Due to human involvement, dams have been built and have caused a barrier for Steelhead and other anadromous fish trying to migrate upstream to spawn. Some dams have fish ladders that are engineered to help fish migrate upstream past the dam, some dams have engineered a method of helping them get downward to the ocean, and others that are too tall to have a ladder. Dam-related impacts are the single largest cause of diminished populations of Central Valley salmon and Steelhead relative to pre western settlement conditions. The Cougar Dam in Oregon has historically altered the temperature of the water downstream which altered the time the fish migrated, spawned and when the eggs hatched. Smolts are at risk if swimming upon warm bodies of water. They are incapable of surviving at that stage of life in too warm of water. Proposed solutions involving these issues are to install more wind turbines and to tear down the dams that are directly impacting the ecology of our river systems. There are methods scientists and engineers have designed to help transport migrating fish over these dams such as a fish ladder or long vertical tubes that go from water to over the dam that essentially