Aquaculture is the world’s fastest growing food sector – one that proponents have long argued can help conserve wild fisheries. The argument goes that farming seafood instead of catching it will provide respite to over-fished species at sea.

Farmed fish themselves also need to eat, however. And some of the world’s most valuable species, like salmon and trout, are fed on fish from the ocean.

In fact, according to a new study, published in October in the peer-reviewed journal Science Advances, kilo-for-kilo, carnivorous fish such as salmon and trout eat far more seafood than they provide.

These results suggest that, contrary to the aquaculture’s sustainability claims, the global fish farming industry uses as much as 307 percent more wild fish than previously reported.

A separate review, published in the same journal, found that while the sector has repeatedly claimed to be reducing its hunger for wild-caught fish, it was using “misleading and … often inaccurate” figures, which downplay its demand…