Overfishing has rapidly depleted the populations of fish commonly used for sushi — and it's only a matter of time before some species go extinct, experts warn.

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Pacific bluefin tuna populations are down 95 percent, prompting conservation organizations to call for limitations on commercial fishing. Federal catch limits for red snappers have helped the population rebound slightly, but it's not expected to fully recover until 2032. The National Oceanic and Atmospheric Administration listed Atlantic halibut as a "species of concern" in 2004.

In spite of the reduced supply and fishing restrictions, demand for sushi is higher than ever. The sushi industry grew by about 3 percent from 2011 to 2016, according to the business analysis company IBISWorld.

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That's leading some sushi restaurants to swap out certain fish for species of lower quality — unbeknownst to customers. In 2013, the ocean conservation organization Oceana found that about 74 percent of sushi is mislabeled at restaurants in the United States. And at sushi venues in Los Angeles in particular, almost half of the fish sold is different than what's claimed on the menu, TimeOut reported.

Paul Barber, a UCLA professor who authored the LA-based study, wrote in the journal Conservation Biology that "it’s hard to know where in the supply chain it begins," but he suspects "in some cases the mislabeling is very much intentional."

ATTN: produced a video exploring the overfishing problem, which you can watch in full below.