Light Exposure Affects Photosynthesis Essay

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Freshwater creek is a freshwater stream located in North Cairns, and flows through the Redlynch area-which consists of rainforest, housing, farming and recreational areas. In order to have an indication of general health levels for Freshwater creek, measurements of the water parameters must be regularly checked. This is done to maintain health and prevent abnormal water qualities.
Certain water qualities like dissolved nitrates, ammonia and oxygen will be measured at a site upstream from Goomboora Park. This site will be referred to as, Site 1. Measurements from Site 1 will be analysed and compared to water qualities recorded from previous years (2012, 2013, 2014, 2015).
Water is a triatomic molecule, with a chemical formula of H20. At a temperature
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Benthic plants, phytoplankton and submerged algae produce oxygen as a by-product of photosynthesis (refer to Appendix 11). The rate of photosynthesis heavily relies on light exposure, and the ability for the light to reach the plants. Therefore, the turbidity and general light exposure affect photosynthesis. Diffusion is the movement of a particular substance from an area of high concentration to an area of low concentration. Oxygen in the atmosphere goes along the concentration gradient and diffuses into the water until equilibrium is reached. According to Henry’s law the dissolved oxygen content of water is proportional to the percent of oxygen (partial pressure) in the air above it. As oxygen in the atmosphere is about 20.3%, the amount of dissolved oxygen at 100% saturation at sea level at 20° C is 9.03 mg/L (Christine Kemker,2013). 100% saturation is not the maximum amount of solute in a solvent, it is the point of equilibrium. This means that the concentration gradient will always distribute the oxygen in order to eventually reach 100% …show more content…
Ammonia can be found in waterways through nitrogen fixation, decomposition and human induced factors. Nitrogen fixation is the process in which atmospheric dinitrogen is converted into ammonia by biological processes or high energy environmental events like lightning strikes. Decomposition is the term used to describe the breaking down of organic substances. Human induced factors like runoff from agricultural and urban areas also can contribute to the ammonia levels in water. However, ammonia is toxic to organisms so when it is detected in a creek, it is classified as pollution. The reason how ammonia can enter the water and not be detected is because of its ability to quickly yield into other substances. Traces of ammonia at 0.2 to 2.0 mg/l or more are said to be lethal for most fish (Brian Oram, 2014). However, the ideal level of ammonia in a healthy creek is 0mg/L. This topic will be explored

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