Research Questions and Hypotheses

This study attempts to address the following questions:

·        Is there a relationship between the concentration of atmospheric CO₂ and the growth of T. weissflogii?

It follows that if atmospheric CO₂ is a limiting factor, then increasing the concentration of CO₂ in a culture medium would increase growth rate.

·        Does varying levels of atmospheric CO₂ affect the pH of seawater, and if so, how does this change in water chemistry affect the availability of CO₂ for T. weissflogii?

Because CO₂ forms carbonic acid in the presence of water, increased CO₂ concentrations should lower the pH of the culture medium and affect the type and ratio of dissolved inorganic carbon in the medium (CO₂, HCO₃^-, and CO₃^2-).

·        Does varying CO₂ concentrations affect the amount of photopigments in the chloroplasts of T. weissflogii?

If the concentration of atmospheric CO₂ limits the rate of photosynthesis and hence the demand on photopigments, then increasing atmospheric CO₂ should cause an increase in the photopigment concentrations so that the diatoms can take full advantage of the available CO₂.

·        Does varying CO₂ concentrations affect the activity and abundance of the enzyme carbonic anhydrase (CA)?

Because carbonic anhydrase is primarily responsible for converting bicarbonate (HCO₃^-) to carbon dioxide (CO₂), when atmospheric CO₂ is abundant, CA activity should be reduced.

·        Is there a relationship between the population growth dynamics of T. weissflogii and the levels of various inorganic compounds present in the culture medium?

Given that diatoms require specific inorganic compounds to maintain sustainable populations, there should be a strong correlation between the presence of these compounds and the growth of the diatom population.