User:RJ-Limnology/Mývatn

Since Lake Myvatn is shallow, primary productivity is generally dominant at the sediment-water interface. However, the autotrophic structure of Lake Myvatn can vary from year to year, alternating between periods of productive dominance by pelagic phytoplankton and productive dominance by benthic epipelon. Algal blooms can be initiated by nutrient input through groundwater springs containing phosphorus and the stirring up of phosphate-rich sediments. During algal blooms, when primary productivity of pelagic phytoplankton is high, the amount of light that can penetrate to the bottom of the lake decreases. As a result, primary producers at the bottom of the lake cannot photosynthesize as much as they could with greater light saturation. This reduces the relative contributions of benthic primary producers during algal blooms. Periods of great pelagic photosynthetic activity may have longer-lasting impacts, resulting in a decline of the benthic maximum productivity (Pmax ).