Monomictic lake
As warm monomictic lakes are entirely liquid, warmer in temperature, and highly productive, summer stratification commonly leads to eutrophication.
During eutrophication, excess nutrients are produced and depleted in a lake at opposite, vertical ends of the water column.
This in turn dictates the growth and maturation of populations of organisms which tend to influence water oxygen and nutrient levels.
Ideally, higher levels of oxygen aid resident bacteria and microorganisms in the decomposition of organic matter and dispersal of necessary nutrients into the water column.
Eutrophication can be both a natural and an anthropologic process; anthropogenic inputs are typically through sewage and waste water, or agricultural soil erosion and run-off.
[9] A rather new hypothesis is a link between residence time of water and seasonal stratification in monomictic lakes leading to eutrophication.
Current models utilize the redirection of water flow into and out of monomictic lakes to assist in overturn and the physical “flushing” of phytoplankton and excess nutrients.
While these time frames are limited in scope, they show potential to be lengthened for greater results in future studies and various lake models.
[10] Hypolimnetic aeration and oxygenation aims to directly address lowered DO levels in a given lake which leads to eutrophication.
Yet, other organisms, such as zooplankton and fish, benefit from this process as increased aerobic conditions expand their territory in a lake.
This addition to the hypolimnion also reduces mixing of the water column and dispersal of nutrients to feed epilimnion algae.
In some cases, lakes treated via hypolimnetic withdrawal may also experience undesirable water-level reductions and overall increases in average water temperature followed by mixing.
[5] Current changes and trends in global temperatures year round are a formidable threat to aquatic ecosystems.
Current studies support that the combination of increased air temperatures and reduced precipitation impact shallow, monomictic lakes.
Furthermore, cold monomictic lakes may experience less cool conditions year-round leading to increased mixing and changes in thermal stratification otherwise unseen.
