Mercury Risk: Unknown
Flying fish, or tobiuo in Japanese, is exceedingly difficult to find in a U.S. sushi bar. It is only included in this book because the roe of the flying fish, known as tobiko, is popular to the point of near ubiquity.
Simultaneously one of the most puzzling and beautiful creatures in the sea, the flying fish is in a class of its own. Well, technically, it’s in a family of its own. Family Exocoetidae encompasses all of the fifty-odd species of flying fish, which are found throughout the world’s temperate and tropical oceans.
Naturally ranging from hazy orange to deep crimson, these tiny eggs are often dyed many other colors to accentuate the presentation of various dishes. They are often used for garnish, flavor, and texture, but are also sold on their own as nigiri, sometimes crowned with a raw quail egg (uzura no tamago).
Little is known about the health of the world’s flying fish populations. These animals reproduce quickly and in large numbers. In some areas, such as the waters near Barbados, it is certain that heavy fishing has seriously affected local stocks. In other places, however, it is more difficult to tell.
Flying fish are migratory by nature, and in certain areas various populations will mix and interbreed. Fisheries also do not differentiate between the various species of flying fish, but simply catch whatever type is available.
Finally, to make matters even more complex, flying fish roe is harvested all over the world, transported to Japan or Taiwan for preparation (salting, curing, dyeing, etc.), and then reexported. As a result, the box containing tobiko at your local sushi haunt is likely to say “Product of Japan” or “Product of Taiwan,” even though the eggs could be from anywhere.
In the absence of hard data and a transparent chain of custody, what do we do? Sustainable Sushi is based on the theory of the precautionary principle—when a resource isn’t fully understood, it should be assumed to be limited rather than limitless. This notion is one of our greatest defenses against resource depletion and environmental degradation.
The fact that we don’t know much about the tobiuo fisheries is reason to be cautious, not to assume everything is fine. The science is still unclear on this one, so it’s best to exercise moderation until we know more about the fishery. If you have a real craving for roe, try Icelandic masago—it is very similar to tobiko and is known to be a strong sustainable option.