Question

Q4.22. A researcher is studying the global biogeochemical cycling of a particular nutrient, and she has determined that its storage rate in the oceanic subsystem is -10 Pg y-1. What can she conclude based on this observation? Use the dropdowns below to complete your answer. The oceanic nutrient pool size is A, and because Earth's global biogeochemical cycles are , the size of this nutrient's pools in one or more of Earth's other subsystems (besides the ocean) must also be changing. Reset Submit

Answer 1

Nutrient cycles are the cycles that involve the circulation of the nutrients throughout the different components of the environment.

There are different nutrients like carbon, water, etc. that undergo cycling. Most of the cycles on Earth are closed which means that the different components produced during each cycle are used up to produce another component that also takes part in the cycle thereby creating a loop of nutrients. Therefore, the net content of the nutrient on Earth in various different forms more or less stays constant.

An increase or a decrease in any particular form of the nutrient will hence be coupled with a change in the entire cycle and naturally an increase at one end would result in a decrease at another end and so on.

The researcher here is checking for the storage rate of the nutrient in the oceans. Storage rate is a difference between the total flux into the ocean and the total flux out of the ocean. The storage rate given in the question is negative. This implies that the total flux of the nutrient out of the ocean is more compared to the total flux into the ocean.

Therefore, the nutrient quantitity is decreasing from the ocean over time and as mentioned the nutrient cycles on earth are closed, which would imply that a decrease in quantity of the nutrient from the ocean will be accompanied by an increase in the quatnitity of nutrient elsewhere in the nutreitne cycle.