The Pacific saury is a skinny little stripe of silver that occurs in great multitudes along the coasts of the Pacific Ocean. It can be found in the seas around Japan, off the northeast coast of Russia, across the Bering Sea to the Gulf of Alaska, and southward as far as Mexico. These little fish grow quickly, reproduce in large numbers, and are an important food source for many ocean predators.
Sanma is very much a feast-or-famine fish, as it migrates and is generally either present in great numbers or conspicuously absent. When it migrates inshore, it is heavily targeted for fishing. This relative of the needlefish is the base of numerous seasonal dishes in Japan. It is especially popular in autumn.
In the United States, sanma is still relatively unknown. It may rotate through the specials board of a high-end sushi bar during the appropriate season, but it has not yet achieved a strong following. At this point, there is little information on which to base a recommendation regarding sanma. It’s true that the fish is somewhat succored by its rapid growth rate, prolific abundance, and early onset of sexual maturity. It is important to remember, though, that these were also all characteristics of the passenger pigeon as well.
Enjoy sanma responsibly. While it is likely a better choice than many other less resilient fish, try not to order it too often until more is known about the dynamics of the fishery and the species’ overall sustainability.