Question

You are leading an effort to reduce the formation of a dead zone in the Gulf of Mexico during the summer. You are tasked with selecting which company should be hired to help treat water runoff in the area. You provide both companies with identical samples of the water to be treated. The table below shows the results. To which company do you award the contract and why?

Answer 1

Question:

a) l would choose company 1 because they decreased metals the least, and metals kill microbes.

b) I would choose company 1 because they reduced nitrate and phosphate fertilizers the most and these fertilizers contribute to dead zone formation.

c) I would choose company 2 because they decrease the nitrate and phosphate fertilizers the least and these are important for plant and algae growth.

d) I would choose company 2 because they reduced the metals the most and metals are the most harmful contaminant of those listed.

Answer:

Dead zones are places where organisms cannot survive due to the low amount of oxygen in the water.

One of the causes of dead zones is a large number of fertilizers in the water. The increase in fertilizers contributes to the development of aerobic bacteria (which consume all the oxygen in the water) and later of anaerobic bacteria.

So option "b" is correct. Company 1 reduced the amount of nitrate and phosphate based fertilizers (dead zone causes).