Dan Mullen (CC BY-NC-ND 2.0)

Series: Phosphorus In Wisconsin's Land And Water

Phosphorus is an essential building block of life, but it's also one of the world's most common and troublesome pollutants. Intensive agriculture unleashes excess levels of phosphorus in the form of manure and other fertilizers. What plants don't consume of this essential nutrient lingers on the ground or makes its way down into soil. Rain pushes this phosphorus into streams, rivers, lakes and groundwater. When too much enters a body of water, it can fuel blooms of noxious and sometimes toxic microorganisms — a frequent problem in lakes around Wisconsin and in the Great Lakes. Farmers, scientists, environmentalists, and state and local officials are struggling to reach a consensus about how to manage this nutrient pollution while maintaining a robust agricultural industry.
 
Phosphorus has always been a big part of just about any water-quality discussion, including those about its levels in the Great Lakes. It also intersects with another big ecological problem in the lakes: invasive species.
Phosphorus is one of the most important components in the ongoing struggle to balance agricultural prosperity with water quality. What scientists call "legacy phosphorus" — or "legacy P," a common abbreviation — exists in a sort of nutrient limbo.
In a startling turn-about, Lake Superior has lost its championship title as the clearest of the Great Lakes.
Federal officials are launching a two-year study to determine the best ways to convince farmers to help fight water pollution in the Great Lakes region.
Phosphorus is a well-known culprit for water quality problems in Wisconsin, and an excess of this nutrient in soils impedes efforts to clean up lakes. Several groups of people play critical roles in reducing phosphorus pollution and improving lakes – farmers, policymakers and scientists, to name a few – but how does the "average" person fit in?
All around Wisconsin, people are feeding a stinky, green and oftentimes toxic life form.
It's never an easy conversation to have in Wisconsin: Phosphorus pollution afflicts bodies of water all over the state, and its primary source is agriculture.
Why exactly does Green Bay need saving? Because it suffers from too much phosphorus, which contributes to cyanobacteria, more commonly known as blue-green algae.