Phosphorus is an essential element in all-living things—plants and animals. However, humans in the Lake Simcoe watershed have over the years upset the ecosystem by allowing too much phosphorus to run into the waters. There are many contributing factors ranging from run-off from agriculture, to residential and other uses of fertilizers containing phosphorus, to the destruction of buffer zones near the water’s edge. But the result is that this excessive phosphorus is causing a complex and deathly cycle called eutrophication—water pollution caused by excessive plant nutrients.

Here's what's happening:

• Too much phosphorus is causing algae and weeds in the water to multiply.

• The algae and weeds flourish, then die, decompose and accumulate as sediment.

• Bacteria populations grow in the sediment and use up the oxygen in the water.

• Too little oxygen interferes with the life cycles of fish and other creatures.

• When oxygen levels become low enough, fish suffocate and some species are wiped out.

• If a lake can’t support fish, it’s not good for people either.

For more information on nutrient pollution and its effects go to:

Eutrophication: (Nutrient Pollution)