UNDERSTANDING EUTROPHICATION

For centuries, nature has maintained the delicate balance of water quality and prevented eutrophication by efficiently clearing nutrients through the food web.

This natural process established the foundation of Renewable Water as a sustainable resource. However, since the Industrial Revolution, increasing nutrient loads from manmade infrastructure, as well as the growth in crop and livestock food production, have disrupted this equilibrium.

Rivers, lakes, and reservoirs should be cherished as Natural Water Infrastructure assets but are being degraded by eutrophication and becoming liabilities.

Eutrophication is the process that transitions a water body from a nutrient clearing ecosystem that naturally maintains water quality to a nutrient recycling ecosystem that degrades water quality.

This shift is driven by the interaction and feedback between several key factors caused by the increase in nutrient inflows:

1. Excessive phytoplankton production: When unconsumed algae die off and sink to the sediment and decompose.

2. Hypoxia or oxygen depletion: As the algae decompose in the sediment, oxygen levels in the water decrease.

3. Sediment nutrient recycling: Decomposed algae release nutrients that recycle back into the water, amplifying and intensifying the process of eutrophication.

4. Reduced habitats for aquatic life: The oxygen depletion decreases the availability of oxygenated water and sediment that enable animals in the food web, such as benthic zooplankton and fish, to survive and function.

Invasive weeds also play a significant role in eutrophication. They take root in the nutrient-rich organic sediment. When they die off, the weeds decompose, further depleting oxygen and increasing sediment nutrient stockpiles.

This creates an ideal environment for toxic cyanobacteria to take hold and dominate the aquatic ecosystem, resulting in harmful algae blooms or HABs.

In a healthy aquatic food web, plant life and algae use nutrients to produce primary biomass, which supports progressive levels of animal life. Zooplankton consume algae and produce animal biomass that is then consumed by higher-order animals in the food web.

Eventually, nutrients are cleared from the ecosystem when predators like bears, otters, birds, and people remove biomass by removing prey animals, such as crustaceans and fish.

However, when nutrient overloads fuel rapid blooms of invasive weeds, algae, and cyanobacteria, the food web becomes overwhelmed.

Animals can no longer consume all the short-lived plant life before it dies. Then leftover dead biomass sinks to the bottom, decomposing and producing nutrient rich stockpiles in the sediment. This process depletes oxygen at the base of the water column, creating anoxic conditions that are hostile to oxygen-respiring animal life.

As a result, invasive weeds, algae, and cyanobacteria gain a competitive advantage, taking over in successive stages and marginalizing animal life.

Through these various processes, an ecosystem regime change takes place, resulting in a stable system where perpetual recycling of sediment nutrient stockpiles replaces nutrient clearance as the defining characteristic.

Eutrophication becomes a self-sustaining, self-reinforcing cycle that cannot be reversed by current reactive treatments that focus only on the problem’s symptoms.

To address eutrophication effectively, the root causes must be recognized and addressed with targeted remediation treatments:

By focusing on these three key aspects – Reoxygenation, Bio-Dredging, and Restoring Ecosystem Balance – we can reverse eutrophication, eliminate muck and the invasive weeds they promote, control excess algae, prevent HABs, and restore ecological balance. This holistic approach is the key to saving our precious water resources and preserving the cherished Lake Lifestyle for generations to come.