Biogeochemical Cycles In Biology

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Biogeochemical cycles are the way in which nutrients move through the earths system. It is a pathway for chemical elements to move through biotic and abiotic factors. The ocean contributes largely to these cycles as it acts as a reservoir or sink for the accumulation of nutrients. Even water itself is recycled through precipitation, evaporation and condensation. This is a typical cycle that can be observed for the vital elements of life such as carbon and nitrogen. Microbes are essential to the cycling of nutrients in virtually all environments, including extreme ones such as hydrothermal vents and acid lakes. Specifically in the marine environment, they are a building block to carbon flow, organic matter decomposition and nutrient cycles.(ref). …show more content…
The role of carbon fixing by photosynthetic organisms in the ocean is massive, providing 90% of the organic carbon. 50% of this is provided by cyanobacteria alone, specifically Synechococcus and Prochlorococcus species, having the principal impact on primary production in the marine environment (OA and O’Brien paper). These photoautotrophs along with others have developed a mechanism (carbon – concentrating mechanisms) that allows them to take up and use bicarbonate ions to defeat the limited CO2 concentration (Surajit Das and Neelam Mangwani, 2015). If they increase their photosynthesis rate and their mass of blooms it would result in a larger region that would have a limitation of nutrients such as phosphate. This was shown by Ray et al.. through microcosm studies. They also showed that their phytoplankton had a tolerance to the fluctuation in pH, although, I feel a limitation to their study would be that the changes in pH were abrupt and the study was only done over five days. Another study was carried out on the impacts on coccolithophore, Emiliania huxleyi blooms by (Engel et al.)….showing a decrease in calcification production rates when CO2 that mimicked the predicted rates for the end of the century were applied. So again it was through an abrupt change that these results were taken. Whereas Iglesias – Rodriguez et al. goes on to …show more content…
2013). The N2 and CO2 fixation and an increase in growth with increasing CO2 levels only occurs with iron replete environment. (Fu,F., Mulholland..). The more carbon and nitrogen fixation increases with an increase in atmospheric CO2 the more iron that is used up, in particular by phytoplankton. Thus the bioavailability of iron may reduce due to OA. Models of diatoms for Atlantic surface water have displayed them taking up iron at a slower rate in response to OA but phytoplankton’s requirement of iron is unchanged with increasing CO2 levels. Therefore, it is likely that there will be an iron stress on phytoplankton population in certain areas with the on-going acidification. (Shi D.,

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