How can nutrients become pollutants in bodies of water?

Question

I need a really good anwser!!!!!

Answer 1

If too many fertilizers are dumped into water source, algae will over grow taking up all the oxygen choking other life forms in the water.

Answer 2

The most problems are caused by the nutrients nitrogen & phosphorus. When nitrogen & phosphorus run off agricultural lands or city lands where fertilizers have been used, they cause ecosystem problems in lakes, rivers & other natural bodies of water.

"Nutrients" may not sound like a bad thing, and it's only in excess that they really cause a problem. In most waterways, phosphorus is the limiting nutrient. This means that the growth of algae in that body of water is limited by phosphorus (there are enough other nutrients, but not enough phosphorus).

When man-made nutrients come into the water, the algae are thrilled - there's lots of food all of a sudden so the algae multiply like crazy (this is called an algal bloom). As the algae die, they decompose and consume oxygen. As the number of algae increase, they use more and more oxygen in the water. They also start to block light from plants growing on the bottom of the waterway.

The most serious problem is the use of oxygen. As levels of O2 decrease on the bottom of the water, species of fish & other aquatic organisms start to die off. This can lead to what's called a fish kill, or massive die-off of fish. A body of water can even become anoxic, meaning there is no dissolved oxygen in the water. This would make that body of water unsuitable for any life.

I don't know if this is a "really good answer", but you can find more information about this on wikipedia.org. Look up "eutrophication" (the greening of waterways through excess nutrients), "algal bloom", "fish kill" or some of the other links you'll find through those three.

Answer 3

As Geo~ said, an increase in nutrients leads to over growth of local algal populations. This increases sedimentation, decreases light absorption of the water, and increases oxygen consumption. The proper term you should look up is "Eutrophication".

There are many tremendous examples out there. In particular, I believe there was a fantastic example of several lakes in Massachusetts becoming dead zones and their populations of eel grass dying out. Look into it, it's fascinating.

Answer 4

.... because it disturbs the balance. (too much phosphor in the water for example leads to too much algae growth.... uh- yeah... somebody already said that)