Scientists studying the decline of certain fish stocks in the Pacific have found a novel research tool: Hawaii restaurant menus.
Kyle Van Houtan, with the Pacific Islands Fisheries Science Center in Honolulu, and mainland colleagues analyzed 376 menus from 154 restaurants in Hawaii from 1928 to 1974.
They found a sharp shift to deep-ocean species as nearshore fisheries declined.
"Reef fish, jacks, and bottomfish were common on menus before 1940, but by Hawaii’s statehood in 1959 these items appeared collectively on less than 10 percent of the menus sampled," the scientists reported in a letter Aug. 1 in the journal Frontiers in Ecology and the Environment. "This period marked a rapid growth in pelagic (open-ocean) fisheries and concurrent declines in nearshore fishery stocks."
By 1970, 95 percent of the menus contained "large pelagics" such as tuna, the study found.
"The decline in reef fish in just a few decades was somewhat of a surprise to us," said co-author Jack Kittinger, a fellow at Stanford University’s Center for Ocean Solutions in Monterey, Calif., in a statement Monday. "We knew at the outset the menus would have a unique historical perspective, but we did not expect the results to be so striking."
Van Houtan said most of the menus came from private collections as well as the Harriet "Rusty" Thomas Collection at Kapiolani Community College, the New York Public Library, the Los Angeles Public Library and the library at the University of Nevada at Las Vegas.
"I found the private collections by word of mouth, speaking with local Hawaiiana experts, cooking historians, publishers, archivists … and just by meeting people on eBay," he said by email Wednesday. "They would invite me to their home, we would rummage through boxes in their garages, and we would talk story for a while."
Restaurants at some of Waikiki’s trendy eateries would issue a menu daily so tourists could take it home.
"They were often beautifully crafted, date stamped and cherished by their owners as art," Van Houtan said. "The point of our study is that they are also data."
The Jan. 10, 1935, menu from the Royal Hawaiian Hotel, for instance, offers "Poached Paakii Veronique." The March 3, 1938, menu from the Royal Hawaiian offers broiled fresh Hawaiian mackerel with cucumber string, mustard sauce and gaufrette potatoes. Locally caught mackerel, or opelu, and pakii, or flounder, were uncommon on later menus, Van Houtan said.
"The frequency of their occurrence on menus diminished dramatically," he said by email.
Recent menus have mostly mahimahi.
Market surveys and government statistics are the traditional sources for tracking fisheries.
But the government hasn’t always compiled statistics as religiously as it does today.
"When those records don’t exist, we have to be more creative," Van Houtan said. "Here we found restaurant menus were a workable proxy that chronicled the rise and fall of fisheries."
The study began when Van Houtan, leader of the Marine Turtle Assessment Program, was checking mid-20th-century restaurant menus for turtle meat. He found none but realized it was possible to use menus to track other species.
"Hawaii is perhaps an ideal location to use menus to analyze historical changes in the marine environment because its remote location meant mostly locally consumed seafood was locally sourced," the scientists’ letter said. "When compiled and interpreted in the appropriate socioeconomic context, menus have a great potential as a window to the past."
Contributing to the study was Loren McClenachan of Colby College in Maine.
