The answer would most likely be a metaphor, sorry if I’m wrong!
Fast growing Salmon to me would be a freak of nature. Most likley some idiot put some steriods in the ocean, but also must mean something is happening with where they live and they are trying to adapt to what has happened.
Well, there could be many reasons. First off, there are many different historical and cultural differences between Shakespeare's time and modern times that a modern student doesn't pick up on, doesn't understand.
Second, you simply have to take into account the fact that, with modern technology, students' attention spans have gotten so bad that simply reading Shakespeare plays is "too boring" for them.
Modern students want quick answers, a bubble they can circle on a multiple choice test type of answer. Interpreting Shakespearean plays requires thought and critical thinking, things that, I'm sorry, but no students seem to use nowadays.
Also, there is the small fact that, especially amongst teenage males, things like plays and reading Shakespeare are labeled as feminine or "gay".
Situational irony results when things happen in precisely the way we didn't expect them to.
The issue of Phillip's vision causes some situational irony: the only time he literally sees Timothy clearly is when he fails to "see" him as the kind man he is instead of an untrustworthy black man, which he isn't. And then Phillip goes literally blind and only then learns to "see" Timothy correctly.