User:Kelseyhicks38/sandbox

Temperature

Fig 1: Steelhead- Sacramento River near Yuba City, CA

Poikilotherms

The temperature of the water Steelhead swim in is crucial for their development and survival. Salmonoids are considered ''poikilotherms'' meaning temperature influences their life events, like spawning.Water temperature is one of the most important environmental influences on the salmonoid biology. Temperature determines when the Steelhead will begin migrating upstream, which also determines their spawning time, which effects the time the fry will hatch. The development of steelhead eggs are also dependent on a certain temperature of the water. The temperature steelhead prefer to spawn in range from 3.9 - 9.4 degrees Celsius. No salmonids species can survive in temperatures exceeding more than 25 degrees Celsius (77 degrees Fahrenheit). Unfortunately in California, there has been longer-drier seasons than cold-wet seasons and that will cause an increase in California's river system temperatures to rise. Climate change is warming our waters and that leaves the future for Steelhead lethal.   

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 effecting the organisms that reside in our freshwaters. 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. Having an increase in water temperature makes Steelhead incapable of handling further stressors and makes them more susceptible to parasites and pathogens. These warmer waters magnifies the biotic relationships and increases parasitism. A study was done experimenting 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.

Fig 2: Steelhead-Sacramento River near Yuba City, CA

Dam Installments

Due to human involvement, dams have been 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 pumps water and the fish over the dam. This seems to work on small scale dams maxing 30 feet.

Natural Disasters

Natural disasters are occurring more frequently due to climate change. Fires being more frequent means more obstacles for these Steelhead to complete their journey back upstream. Fires burning alongside our rivers and watersheds cause river pollution with debris and runoff. These reoccurring fires are also burning key vegetation alongside the rivers and watersheds that keep the water temperature cool while constantly being shaded. Vegetation alongside the water also helps with less evaporation occurring because of less direct sunlight beaming on it.