Some news articles that stimulate our consideration of halakhic standards.
Here is the case of …
While livestock and fowl, which halakhically require she’hitah, need to be produced under strict kashrut supervision, fish is exempt from the requirement of ritually regulated slaughtering, and may be purchased without supervision. Nonetheless, purchasing fish from an unsupervised merchant is not worry free. Substitution by related species is quite common, even though sometimes a genus consists of both kosher (with scales) and non-kosher species (lacking scales). Thus, fillets should not be purchased from unsupervised stores, unless they are made into fillets in presence of the customer, so that the customer can identify the fish first, usually by seeing the skin with scales still attached (exception: salmon may reliably be identified by its peculiar pink flesh).
Nonetheless, many kosher customers are either not aware of the severity of matter, or consider substitution unlikely. So, the following report may come as a surprise:
Here we developed a … key for the identification of all tuna species of the genus Thunnus, … for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City) and Denver, Colorado. … A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of “white tuna” were not albacore (T. alalunga), but escolar (Lepidocybium flavorunneum), a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus) or the critically endangered southern bluefin tuna (T. maccoyii), though nine restaurants that sold these species did not state these species on their menus.
The Real maccoyii: Identifying Tuna Sushi with DNA Barcodes
This study merely confirms what two high school students discovered through their freelance science project:
Many New York sushi restaurants and seafood markets are playing a game of bait and switch, say two high school students turned high-tech sleuths.
In a tale of teenagers, sushi and science, Kate Stoeckle and Louisa Strauss, who graduated this year from the Trinity School in Manhattan, took on a freelance science project in which they checked 60 samples of seafood using a simplified genetic fingerprinting technique to see whether the fish New Yorkers buy is what they think they are getting.
They found that one-fourth of the fish samples with identifiable DNA were mislabeled. A piece of sushi sold as the luxury treat white tuna turned out to be Mozambique tilapia, a much cheaper fish that is often raised by farming. Roe supposedly from flying fish was actually from smelt. Seven of nine samples that were called red snapper were mislabeled, and they turned out to be anything from Atlantic cod to Acadian redfish, an endangered species. (New York Times, 22nd of Aug. ’08, Fish Tale Has DNA Hook: Students Find Bad Labels)
Obviously, the warning bells ring even louder against the practice of eating “milchig treif,” i.e. ostensibly kosher fish in a non kosher restaurant. Not only may such fish or vegetarian dish be spiked with non kosher flavorings and sauces, not only will it generally run afoul of the prohibition of bishul akum, but, as it now turns out, the main dish may be an actual piece of biblically prohibited scaleless fish.
Plus, as the article points out, it’s a health hazard and/or may contribute to destructions of endangered fish species. Clearly eating kosher is good for Jew and gentile alike.