Consider the aquatic phosphorus cycle. phosphorus is the limiting nutrient for aquatic organisms. decomposition naturally returns phosphorus to the aquatic cycle, but phosphates from fertilizers, sewage and detergents can cause pollution in lakes and streams. over-enrichment of phosphate in freshwater can lead to which, when they die and decay, leads to a) a lower ph; acidification b) algal blooms; eutrophication c) turbidity; decreased photosynthesis d) increased decomposition; poor growing conditions