Activity 9: What Do You Think?

• Excess nitrogen comes from fertilizers and car exhaust.
• Too much nitrogen results in overproduction of algae known as algal bloom. Depletion of the oxygen supply occurs and this results in the death of other organisms.

Student Conceptions
Students think that since detergents kill germs then necessarily they would also kill algae. Another misconception would be that since fertilizers are good for plants then it must also be good for algae.

This may be the first time that students will get introduced to the concept of beneficial bacteria. They have been exposed to the idea that bacteria are harmful.