[[This isn't to change your mind. It is intended to inform.]]
A real world example of supply and demand that once again involves a developing or a poor nation. In West Africa there is a lack of police force to keep people in check by enforcing a limit on what one boat can catch:
"The skippers of the illegal fishing boats tend to favour the waters of some of the poorest nations, which are often inadequately policed as a result of a lack of resources...For centuries, the waters have supported generations of small coastal communities, but as the world's appetite for fish continues to grow, the rich fishing grounds have attracted the attention of illegal vessels".
I'm not completely sure how they manage to sell $9 bn worth of fish a year without seeming... fishy. I read from the website [guardian.co.tt] that in Orange Valley, i believe located in Spain, they go through the "backdoor" of ports and sell off their load to stores, vendors and on the street for half the price with the local people knowing full well what's going on. They may be scared to speak out or it can also be the lack of authoritah. It turns out that their leaders do know what's going on but due to no evidence they cannot act. But, it turns out that these fisherman are paying the port owners a little something on the side to unload their cargo.
The increase of illegal fishing can be tied to the increase of fish consumption. It's much like the increase of meat consumption which can be linked to the increase of deforestation. To help with deforestation nations have taken on consuming and buying more coffee product. Coffee purchased from developing nations, such as Brazil, help decrease deforestation because less trees are cut down to make room for cattle and more native coffee bean plants are planted. People flock to where the money is. So if less fish is consumed we can therefore decrease the practice of illegal fishing and over fishing.
Some ways to do so are to limit your fish intake or if you want to go full force, try becoming vegetarian. I've tried being a vegetarian for a long while and constantly had near slips. Yes it is difficult but so is walking. Once you master it you become a natural. But you know, whatever.