A recent study from researchers at UCLA and Loyola Marymount University checked the DNA of fish ordered at 26 L.A. sushi restaurants over four years and found that 47% of the sushi was mislabeled.

It’s an alarming number and it’s not unique from research completed in different cities by other universities, news outlets, and NGOs. Fraud is illegal, and reports like this help shine a light on the necessity of regulators to be more stringent about enforcing laws that crack down on this criminal act.

What is also alarming, however, is the suggestion that this research indicates the fraud “may occur earlier in the supply chain than the point of sale to consumers.” That may be the case but this conclusion is not based on science or the research completed here.

The study, similar to the previous research in other cities, only completes 2 out of 3 steps.

To find out where the real fish fraud happened, researchers need:

1. A menu showing what the fish is called
2. A DNA sample of the fish
3. An invoice from the restaurant showing what fish they ordered from a supplier

If the invoice says the restaurant ordered snapper, and the menu says it’s snapper, but the DNA test shows it’s tilapia, then you know the restaurant was not at fault and thought it was providing customers with snapper. If the invoice says the restaurant ordered tilapia, the DNA test shows it’s tilapia, but the menu calls it snapper, then you know the restaurant purposely changed the name of the fish on the menu, but knew that the fish they were providing was really tilapia.

This is not rocket science.

The senior author of the study claims that “one has to think that even the restaurants are being duped.” Why? His own research is not able to tell where the switch happened and he even notes in the same release, “it’s hard to know where in the supply chain it begins.” It’s irresponsible to publicly opine about fraud happening at the supplier level when this particular research provides no evidence to demonstrate that.

In this case it would appear to have taken four years to solve half a riddle. Perhaps resources would be better spent solving a whole riddle. Yet another study that says “we found fraud,” without providing any real insight into where the fraud happened or who is responsible for it, makes headlines but doesn’t make headway in solving this challenge.