Ascientist is using bromthymol blue to analyze a solution. what is the scientist most likely doing?

I believe the scientist wants to test for the presence of carbonic acid in the solution. Bromthymol blue is a PH indicator and is mostly used in applications that require measuring substances that would have a relatively neutral pH. A common measure is for the measuring the presence of carbonic acid in a liquid.
It may be used for observing photosynthetic activities, or as a respiratory indicator. As a carbon dioxide is absorbed from the breath into the solution, forming carbonic acid, the solution changes color from green to yellow.

Iwould say overuse ( but not 100% sure ) in the u.s. we tend to overuse water by leaving it running, throwing it away, taking long showers, etc.