Shayne, that's a broad statement. If people do nothing, nothing gets done.
A simpler explanation, if your crew all decide to take a day/week off, you catch no fish. No fish = no income, for them and you.
GOK, to have legislation, the powers that be worldwide all need to be on the same page for the same issue, and assuming that legislation is put in place, it still requires the cooperation of those same people Shayne says need do nothing.