Putting aside years of conspiracy theories, the Miami Herald commissioned Nova Southeastern professor Mahmood Shivji’s to use DNA fingerprinting technology to confirm that the McDonald’s Filet-O-Fish sandwich is actually made of fish.

Alaska pollock.

McDonald’s corporate website identifies pollock as one of two fish sources for its decades-old fish sandwich (the other being hoki, a fish found off the coasts of New Zealand and Australia).

Both fish species are recognized as sustainable, well-managed fisheries — meaning Filet-O-Fish lovers can feel good that their guilty pleasure won’t harm Mother Nature’s marine ecosytems.