It was a brilliant idea. When scientists in Hawaii tried tracking long-term changes in local wild fisheries, decades of nonexistent fishery records had them stumped. How do you piece together population information when critical data was missing? The answer came from a surprising source: decades-old restaurant menus tucked away as souvenirs by tourists who had visited iconic restaurants like Trader Vic’s and Prince Kuhio’s, as well as local seafood dives.
“We knew at the outset the menus would have a unique historical perspective, but we did not expect the results to be so striking,” said co-author Jack Kittinger of Stanford University’s Center for Ocean Solutions.
According to the report published last week in the journal Frontiers in Ecology and the Environment, the group of researchers analyzed 346 menus from 154 restaurants and discovered that near-shore species like rock fish, jacks and bottom fish were once common on Hawaiian dinner menus prior to 1940. But by the 1970s, those tasty local species barely made an appearance. In their place were species we commonly eat today, like tuna and swordfish.
The menus, which stretch from 1920-1974, were then combined with the fisheries data the researchers did have, and used to take a data “snapshot.”
“Fish like snapper and flounder and grouper—they really took a nosedive,” Kyle Van Houtan, an ecologist with the National Oceanic and Atmospheric Administration and co-author of the study, tells NPR. “These are very desirable fish. They used to be on the menus. We see them on there in the 1930s and 1940s, but they’re not in any of the menus today.
Obviously, menus are not perfect scientific tools to study fisheries data. An item like shrimp has been a regular on Hawaiian menus for decades, but may have been an imported product. Turtle, on the other hand, was most likely sold at local markets, rather than to restaurants catering to tourists.
But we think the idea is innovative, and hope it catches on with other scientists.
“Historical ecology typically focuses on supply-side information, said Loren McClenachan, a co-author of the study. “Restaurant menus are an available but often overlooked source of information on the demand side, perhaps a modern equivalent to archeological middens, in that they document seafood consumption, availability and even value over time.”