And the Asian aquaculture juggernaut didn’t stop with shrimp. In fact, shrimp was a doorway into another seafood swap, which leads to the next course.

Fish Sticks: Atlantic for Pacific

Most seafood eaters know the sad story of the Atlantic cod. The ill effects of the postwar buildup of industrialized American fishing are epitomized by that fish’s overexploitation: Gorton’s fish sticks and McDonald’s Filets-o-Fish all once rode on the backs of billions of cod. The codfish populations of North America plummeted and have yet to return.

Just as the North Atlantic was falling as a fish-stick producer, the Pacific rose. Beginning in the 1990s two new white fish started coming to us from Asia: tilapia, which grows incredibly fast, and the Vietnamese Pangasius catfish, which grows even faster (and can breathe air if its ponds grow too crowded). These two are now America’s fourth- and sixth-most-consumed seafoods, respectively, according to the National Fisheries Institute.

Alongside them, a fishery arose for an indigenous wild American Pacific fish called the Alaskan, or walleye, pollock. In just a few decades, pollock harvests went from negligible to billions of pounds a year. Pollock is now the fish in McDonald’s Filet-o-Fish and the crab in the “fake crab” that Larry David discussed mid-coitus on “Curb Your Enthusiasm.” In fact, there is so much pollock that we can’t seem to use it all: Every year more than 600 million pounds is frozen into giant blocks and sent to the churning fish processing plants of Asia, Germany and the Netherlands.

Sending all this wild fish abroad and then importing farmed fish to replace it is enough to make you want to take a stiff drink and go to bed. But when you wake up and reach for your bagel, surprise! The fish swap will get you again.

Lox: Wild for Farmed

There was a time when “nova lox” was exactly that: wild Atlantic salmon (laks in Norwegian) caught off Nova Scotia or elsewhere in the North Atlantic. But most wild Atlantic salmon populations have been fished to commercial extinction, and today a majority of our lox comes from selectively bred farmed salmon, with Chile our largest supplier.

This is curious, given that salmon are not native to the Southern Hemisphere. But after Norwegian aquaculture companies took them there in the ’80s, they became so numerous as to be considered an invasive species.