COOL Classroom 2.1

Discover The Pollution Solution

How can we help prevent dead zones in the ocean?

What is the causing the pollution problem?


Phosphorus and nitrogen are elements that are necessary for plants to grow (DNA and RNA require it, for example). Too much of these nutrients in lakes, rivers or even the ocean can cause an explosive growth of algae, a process which is called eutrophication. Algal blooms can ruin sources of drinking water, clog boat engines, block out sunlight, obstruct fish gills, and prevent filter feeding. Blooms are unpleasant to swim in, which not only directly affects tourists but also can hurt the tourism industry. On top of all of this, when the algal blooms die off, masses of bacteria congregate to break down the dead algae. The bacteria use up huge amounts of the oxygen in the water through the process of decomposition, which is the breaking down of organic matter. The low oxygen areas are termed hypoxic, and the lack of oxygen can cause fish and other marine life to die.

Eroding the problem

Increased erosion is also contributing to increasing dead zones. By removing natural vegetation, such as trees, grasses and plants for development and farmland, we are removing the roots that help to keep the soil in place. When the soil erodes into streams, lakes and rivers it brings with it the nutrients from the farms and backyards where it originated. In order to lessen the effects of this problem you should plant native vegetation which tends to have deeper roots that stabilize the run-off and soil more effectively. Native vegetation is sometimes able to out-compete weeds and provides habitat for wildlife.

Where does phosphorus come from?


Phosphorus comes from many different sources. One source is lawn fertilizer. Some areas already have enough phosphorus in their soil and when people fertilize their lawns, the excess phosphorus runs into the rivers when it rains. In order to prevent this problem have your soil quality tested to see if you actually need to use fertilizer. Other sources of phosphorus are leaves and grass clippings that are left on the street near storm drains. When they decay they release phosphorus and when it rains the extra nutrients run into the rivers contributing to eutrophication. To stop this from happening make a compost pile for your leaves, grass clippings, and even your food wastes. Using the nutrient rich mulch you make from your compost can cut down on having to use fertilizers for your gardens.

Other major contributors to the phosphorus problem include agriculture and sewage treatment plants. Sewage treatment plants turn your waste into a nutrient rich soup. When nutrients from the treatment plant flow out into the rivers and oceans it adds to the excess nutrient problem. Even animal waste such as your pets and livestock contribute. When it rains, nutrients from the decaying waste material washes into the rivers and streams. One way to prevent this is to clean up animal wastes regularly and before major rainfalls. Fertilizers from farms are one of the largest contributors to increased nutrients. You can help alleviate this problem through consumer choices such as purchasing organic products that do not use fertilizers.

Urban Issues


Urban development also contributes to the problem of explosive algal growth and dead zones. Where does rain and snow melt go? If you live in the city it most likely runs from your yard (if you have one) down your driveway, into the street and down into the storm drains. Do you know where the water goes then? Many people think it goes somewhere to be treated and cleaned, but that is not true. From the storm drain the water flows directly into lakes, rivers and streams. Along with it goes all of the pollution and nutrients that were in your yard, on your driveway, and in the street.

When we develop natural areas for urban use, such as buildings, roads, and parking lots, we are changing the natural water flow patterns. Concrete prevents rain from soaking into the soil. This forces it to become runoff, which adds to the pollution problem. So, next time you hear about plans to build a new parking lot instead of a park and you have a chance to voice your opinion, you should! A park would be porous ground cover and allow water to seep into the soil and decrease runoff. This in turn would decrease the amount of nutrients in our waterways.

What can you do?

So remember, in this case, we can all make a difference.

  • Use fertilizers on your lawn only when you need to and do so sparingly. Remember to test your soil quality.
  • Make compost out of your leaves, lawn clippings and food wastes. The mulch can be used for your gardens. The nutrients from the decaying organic matter will act as a natural fertilizer for your plants.
  • Plant an extra tree, some native wild flowers, more grasses and maybe even a few bushes! The extra vegetation will decrease erosion. Remember to plant native vegetation because it is better for the ecosystem.
  • Pick up animal wastes right away.
  • Making consumer choices such as supporting organic products that use little or no fertilizer and purchasing detergents that are organic and phosphorus free.
  • When you are old enough, vote! Know what the consequences can be for our oceans. Voice your opinions.

Quiz on Nutrient Pollution!

1. Large algae blooms can be harmful for all of the following reasons EXCEPT:
a. Clog fish gills
b. Cause dead zones in oceans
c. Prevent filter feeding
d. Drown people
e. Decrease tourism

2. Loss of large amounts of oxygen can cause marine life to die in ____________________areas.
(Hint: rearrange the following letters: OHXCIPY)

3. Planting natural vegetation is better because:
a. It can out compete animals in the area
b. It has roots
c. It provides more habitat for wildlife
d. It is prettier

4. The contributors of phosphorus to the waterways include all of the following EXCEPT:
a. Houses and factories
b. Agriculture and erosion
c. Hypoxia and plant roots
d. Sewage treatment plants and urban development

5. ( T / F ) Urban development increases the pollution that runs off into the lakes and streams which could potentially carry excess nutrients into the ocean.