Dr Rana Hamza Shakil thank you for your contribution to the discussion

The distribution and cycling of trace metals and nutrients in the marine environment is thus of fundamental importance, because they influence marine productivity, the species composition of phytoplankton communities and, ultimately, global carbon cycling. The ocean's nitrogen cycle is driven by complex microbial transformations, including nitrogen fixation, assimilation, nitrification, animus and denitrification. Dinitrogen is the most abundant form of nitrogen in sea water but only accessible by nitrogen-fixing microbes. Probably the most important property of seawater in terms of its effect on life in the oceans is the concentration of dissolved nutrients. The most critical of these nutrients are nitrogen and phosphorus because they play a major role in stimulating primary production by plankton in the oceans. Excessive amounts of nutrients can lead to more serious problems such as low levels of oxygen dissolved in the water. Severe algal growth blocks light that is needed for plants, such as seagrasses, to grow. When the algae and sea grass die, they decay. Nitrogen-fixing bacteria, which convert atmospheric nitrogen to nitrates. Bacteria of decay, which convert decaying nitrogen waste to ammonia. Nitrifying bacteria, which convert ammonia to nitrates/nitrites. Organisms that are involved in nitrogen cycles are nitrogen fixers, nitrifying bacteria, and denitrifying bacteria. Example: Nitrosomonas, Rhizobium, Pseudomonas, and Thiobacillus, etc. Microorganisms drive the N cycle starting with N2 fixation to ammonia, through nitrification in which ammonia is oxidized to nitrate and denitrification where nitrate is reduced to N2 to complete the cycle, or partially reduced to generate the greenhouse gas nitrous oxide. Bacteria in the soil or in plant roots convert nitrogen gas from the environment into solid nitrogen molecules that plants can utilize in the soil. The bacteria within the nodules convert free nitrogen to nitrates, which the host plant uses for growth.