How does AQUAGO resolve issues related to eutrophication? :
With more than 15 years of experience in working with standing bodies of water around the world, the AQUAGO team has developed services and products aiming at reducing the impacts of eutrophication / dystrophication. AQUAGO will work closely with you to select the most efficient solutions to respond to your specific issues and to implement them in the field.
Focus on vertical mixing :
Vertical mixing is based on a simple principle: to use machines to create ascending and descending water flows resulting in a more homogeneous distribution of oxygen throughout the entire volume of water and thus preventing further progress of the eutrophication process.
The generic term, continental aquatic ecosystem, encompasses a large diversity of ecosystems that are all characterized by the omnipresence of water. It involves many types of water: fresh, brackish, or saline waters as well as fast or slow moving waters. The science that studies these systems is called limnology. It classifies them into two large groups: lentic ecosystems (standing bodies of water) that ranges from ponds to lakes to wetlands; and lotic ecosystems (flowing water courses) such as rivers and streams. (According to “le guide illustré de l’écologie, 2007”)
AQUAGO specializes in lentic ecosystems. Depending on their sizes, depths, morphologies, locations, and uses, these ecosystems function and react differently. They are, however, governed by general principles. To understand these principles and their effects on the environment, one has to keep in mind that everything interacts and nothing is isolated.
Definition of standing bodies of water :
A standing body of water results from a natural depression, a dam (moraine, rock slide or landslide), a ridge, etc., that stops or slows down water flow. It does not directly communicate with the ocean. Its depth and the residence time of water are sufficient to allow for the existence of a pelagic area or a stable thermal stratification during part of the year (Pourriot et Meybeck, 1995).
At the geological scale, a standing body of water emerges, evolves more or less rapidly depending on its catchment area, and disappears: natural eutrophication. For example, Lake Baïkal is more than 2 million years old.
Eutrophication of standing bodies of water :
Eutrophication is a natural mechanism leading to the enrichment of the aquatic ecosystem in nutritive elements (such as phosphorus, nitrogen, etc.). These nutritive elements may be of allochthonous origin (runoff and inflow from the catchment area) as well as of autochthonous origin (remains of fish, zooplankton, or plants for example). This increase in nutrients creates a vicious circle of biomass production resulting in the filling of the body of water. The timescale is usually of several thousand and even million years.
However, due to excessive nutrient inflows from catchment areas brought in by effluents and runoffs from various sources (domestic, industrial, agricultural) and/or caused by the use of some water bodies, the timeframe in which eutrophication and decreased water quality is observed can be measured in decades, and in some cases in years. The terms used to describe this phenomenon are dystrophication or eutrophication.
There are multiple signs that illustrate the decrease of water quality.
The main ecological effects are listed below :
• Green waters
• Proliferation of filamentous algae and aquatic plants
• Odor pollution
• Fish kill
• Siltation of water bodies
• Proliferation of cyanobacteria
• Depletion of dissolved oxygen in bottom waters
• Decrease in water transparency
Scales are used to define the eutrophication or dystrophication status of a body of water. The Carlson’s scale presented below is one of the most widely known.
dystrophication status of a body of water. The Carlson’s scale presented below is one of the most widely known.