Background: Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. The nitrogen is a fertilizer in the water bodies. Since there is a lot of nitrogen it causes algae to grow out of control. Figure below shows a pond covered with algae. Algae may use up so much oxygen in the water that nothing else can grow. Soon, even the algae die out. Decomposers break down the dead tissue and use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico. You can see it Figure below .

Situation: Our family was going to go fishing on Saturday. A few years ago we went fishing down the hill from a mushroom farm called Happy Pond. Since that time, there has been a lot of rain and we noticed Happy Pond had a green coating across the top of it. We also thought about going to a new pond in center of the park called Ridge Pond. We are hoping to catch a lot of fish to serve at our family reunion.

Question: Which pond will the family most likely catch more fish, Ridge Pond or Happy Pond?
Answer: Ridge Pond

Situation: Our family was going to go fishing on Saturday. A few years ago we went fishing down the hill from a mushroom farm called Happy Pond. Since that time, there has been a lot of rain and we noticed Happy Pond had a green coating across the top of it. We also thought about going to a new pond in center of the park called Ridge Pond. We are hoping to catch a lot of fish to serve at our family reunion.

Question: Which pond will the family most likely catch less fish, Ridge Pond or Happy Pond?
Answer: Happy Pond

Situation: Our family was going to go fishing on Saturday. A few years ago we went fishing down the hill from a mushroom farm called Happy Pond. Since that time, there has been a lot of rain and we noticed Happy Pond had a green coating across the top of it. We also thought about going to a new pond in center of the park called Ridge Pond. We are hoping to catch a lot of fish to serve at our family reunion.

Question: Which pond has more algae growing on it, Ridge Pond or Happy Pond
Answer: Happy Pond

Situation: Our family was going to go fishing on Saturday. A few years ago we went fishing down the hill from a mushroom farm called Happy Pond. Since that time, there has been a lot of rain and we noticed Happy Pond had a green coating across the top of it. We also thought about going to a new pond in center of the park called Ridge Pond. We are hoping to catch a lot of fish to serve at our family reunion.

Question: Which pond has less algae growing on it, Ridge Pond or Happy Pond
Answer: Ridge Pond

Situation: Our family was going to go fishing on Saturday. A few years ago we went fishing down the hill from a mushroom farm called Happy Pond. Since that time, there has been a lot of rain and we noticed Happy Pond had a green coating across the top of it. We also thought about going to a new pond in center of the park called Ridge Pond. We are hoping to catch a lot of fish to serve at our family reunion.

Question: Does Ridge Pond have more nitrogen or oxygen?
Answer: oxygen

Situation: Our family was going to go fishing on Saturday. A few years ago we went fishing down the hill from a mushroom farm called Happy Pond. Since that time, there has been a lot of rain and we noticed Happy Pond had a green coating across the top of it. We also thought about going to a new pond in center of the park called Ridge Pond. We are hoping to catch a lot of fish to serve at our family reunion.

Question: Does Happy Pond have more nitrogen or oxygen?
Answer: nitrogen