@mr.french:
After reading this chapter a second time, it sounds a lot like Luffy will want to destroy the island so that the Fishmen won't have a choice but to go out and explore the world. Fishman Island may at this point seem like a security blanket for the fishmen in the eyes of Luffy and if he destroys it, then that security is lost, and they'll all have to fight for their rights to live up above.
I partially agree with you on that one, Mr. French.
The entire idea of the Fishmen and Mermen gives me an image of hikikomori or people who were racially disrespected, or more so, the two traits combined. They made the Fishman their own shelter and'd look askance at every new outsider who came to the island. They've taken a tiny little percentage of humans as an example used to raise their children and that very situation continued on for next generations. Luffy, per usual, will want to end this crap and will just have to destroy the island forcing its inhabitants to live with humans. By the end of the series they'll be grateful to him that he opened their eyes, that not every human is a sadistic racist and will worship Luffy as their saviour, much like, or even more than Whitebeard. So yeah, I can actually see it coming.
/Edit:
Couldn't wait to read the chapter so I decided to go through Mangastream's. For Christ's sake, their translator needs to realize that シャボン (shabon) is, like many german, english, russian or french words, derived from the portuguese sabao, which means soap, and it's a fact.