How Caviar Works

What Kinds of Fish Make Caviar?

The sturgeon is a lumbering, toothless fish with a decidedly prehistoric appearance whose eggs are harvested for caviar.

The sturgeon is sometimes called a "living fossil" because of its few adaptations through the millennia. The Acipenser family tree includes 27 sturgeon, although genetic markers have scientists disputing the exact number of distinct species. Some sturgeon, like the beluga, live a century or more and continue to grow -- in fact, one beluga reached a record 4,500 pounds and 28 feet long, which is about the size of a motorhome.

The eggs of each species of sturgeon, except the largely poisonous green sturgeon, can be used for caviar. However, only three sturgeon species -- the beluga, osetra and sevruga -- supply most of the world's caviar. These species live in the Caspian Sea, which is bordered by five nations including Iran, Kazakhstan and Russia. Other bodies of water producing significant amounts of caviar include the Black Sea and Sea of Azov.

Sturgeon are anadromous, which means they can live in both salt and fresh water. They prefer, however, to keep one fin in both worlds. Most live in tidal estuaries where salt and fresh waters collide, then swim in rivers to spawn. Sturgeon annually return to the same place to lay their eggs, and their predictable swim makes them easy targets. When caught, most sturgeon won't fight; they're simply resigned to their fate.

Caviar's premium price, coupled with demand, makes the sturgeon attractive to legal fisheries and poachers alike. Decades of overfishing mean fewer mature fish and scant opportunities to reproduce. This cycle is evident in the Caspian Sea's dwindling beluga population, which has dropped more than 90 percent [source: Science Daily].

Within the last 10 years, a number of efforts have attempted to assuage the sturgeon's collapse. Imported beluga caviar was banned in the United States, the beluga sturgeon was placed on the nation's endangered species list, and international coalitions pushed for stringently reduced fishing quotas. Few measures, however, held up to the continued demand for caviar.

As the caviar trifecta -- beluga, osetra and sevruga -- becomes a scarcity, other sources of roe become more acceptable. It's important to note, however, that caviar made from any other type of fish, such as salmon, is not considered "true" caviar and must contain the species identifier in its name. For example, a tin containing salmon roe must read "salmon caviar" not just "caviar."

Next, we'll discover why impeccable timing pays off when it comes to caviar.