Recent studies indicate that the addition of iron to areas of the ocean could increase productivity. Increased productivity could be beneficial for many reasons. What may be one of the largest negative impacts that could occur with "fertilizing the oceans with iron"?
a. Increased productivity could result in higher respiration rates and regions of depleted oxygen in the ocean.
b. Increased productivity would provide more biomass for subsequent levels on the trophic pyramid.
c. Increased productivity could result in depletion of nitrogen available in ocean waters.
d. Increased productivity would be matched by increased detritus falling to the ocean floor, burying many deep-sea organisms.

Option A

Explanation:

The addition of iron to the ocean can result in increasing the productivity of the ocean. This will affect the life of the organism living in their.

The organism that lives in water respire and use oxygen for this process. Once the productivity of the ocean is increased there is a lack of oxygen in ocean.

The biological demand of the ocean will increase and the organism will be limited in the water as there will not be adequate amount of oxygen left for the organism to consume it because of the increased productivity.

hence, option A is the correct where the increased productivity will lead to increased oxygen demand and its rate will be depleted.

the areas around the equator