Tribbles. They born pregnant and will quickly swallow the island in fur. There seems to be very few if any natural predators for Porgs, so unless the porgs get wise and roll the little fuckers into the ocean to be munched on by big fish they're gonna lose.
I don't think Chewie can make enough Tribble Stew and Tribble Sausage to hold back the tide. And then the Klingons will show up and put a blockade around the planet and send down eradication teams, then one will report what the found to the High Council, and then we'll have Klingon Force users. WHY! WHY ROB!? WHY WOULD YOU DO THIS?!