Nutrients are the main needs for phytoplankton, and it is also a limiting factor of phytoplankton, which is nitrogen and phosphorus. The nutrients can be utilized by phytoplankton even though their presence in water is small.
Generally, the efforts to increase water fertility are carried out by giving organic or inorganic fertilizers. Fertile waters can be characterized by abundant phytoplankton.
However, an increasing amount of nutrients in the water caused Harmful algae and toxic of population explosion (algae blooming). Based on this background, Luthfiana Aprilianita Sari, S.Pi., M.Si, and her team conducted a study to determine the effect of excess nutrients on the presence of harmful algae in Banyuwangi.
“Harmful algae are known to produce toxins that can interfere with the productivity of aquatic biota. It can be a competitor for the lives of other plankton. Oceanic waters that have a lot of Harmful algae will experience productivity problems. Harmful algae, which often dominate the waters with explosion population, generally come from an adverse genus “, said the lecturer at Faculty of Fisheries and Marine (FPK).
An increase in nutrients could be in the form of ammonium, nitrate, nitrite, and phosphate. Increased ammonium caused by ammonium not being oxidized to nitrite. Thus, it is presumably because Nitrosomonas bacterium does not work to remodel ammonium.
While increasing levels of nitrite in the waters could threaten the fish, the reason is that nitrite can oxidize hemoglobin to methemoglobin in the blood, inhibit the process of respiration, change the colour of the blood and gills to brown, and cause damage to the nervous system, liver, spleen, and kidney of fish.
“Besides that, increasing nitrate cannot be underestimated. The existence of nitrate could bring the dominance of diatoms because diatoms need nitrates for cell division needs, whereas Harmful algae are more suitable in environments with high ammonium and low nitrate “, she explained,
Harmful algae are suitable in high ammonium and low nitrate environments. If nitrates are abundant, then diatoms will also be abundant. Diatoms will rarely dominate conditions with minimal nitrate content because not much nitrate can be utilized. So that the presence of excessive nutrients is not utilized properly, but can affect the survival of dangerous algae.
Author: Dian Putri Apriliani
Editor: Nuri Hermawan