I'm confused to what the question is?
There are multiple reasons. The most simple answer is because the rain that we consider acidic has a low pH; it has a higher amount of hydrogen ions.
Why does this happen? One is because of the release of sulfur dioxide into the environment to which we humans often contributed. However, it is also possible that increased levels of nitrogen oxide would have this effect as well. And nitrogen oxide can be released through lightning or volcanic eruptions, so these are occurences in nature that don't have anything to do with humans.
Hey There!!
The answer to this is: When reading this, we saw how this lion fish was put into the Atlantic, and therefore, there's actually one thing that is actually something that we would want to consider, and that would actually indicate that it would be our answer.
Let's take notice in the paragraph on how the following sentence shows that this would be a total accident, and that this animal was putted in this location not by purpose, but by accident, and therefore, this was the actual lead on why humans are at fault for the lion fish problem.
The lionfish was accidentally introduced into the Atlantic Ocean in the 1990s.
This would be your answer, and this would be why it would be that they have adapted very quickly to their homes and all the they have now have.
Your answer: The lionfish was accidentally introduced into the Atlantic Ocean in the 1990s.
Hope It Helped!~ ♡
ItsNobody~ ☆