I often have a hard time figuring out exactly what is meant when exponential/ly is used outside of mathematics. This is especially true for exponential decrease.
Take the sentence:
The number of fish in the lake has decreased exponentially over the past couple of years
Mathematically this would mean a while ago the decrease was rapid, but rate of decrease has decreased (e−x, left figure), which is a good thing (assuming we want fish in the lake). However I believe that the intent of the sentence is the number of fish in the lake is decreasing at an increasing rate (−ex, right figure).
Is it true that decreased exponentially often means negative exponential increase when used outside of mathematics? And if so what are good ways of clearly specifying which kind of decrease you are talking about.