Delta smelt
Hypomesus transpacificus
Family: Osmeridae (Smelts)
Etymology: Hypo = below; mesus = middle; trans = across; pacificus = Pacific Ocean; The name literally means that the fish was thought to be found across (on both sides) of the Pacific Ocean; however, that was due to a misunderstanding -- this fish is found ONLY in the Delta of the Sacramento and San Joaquin Rivers.
Such a little fish; so much controversey.
Probably the most controversial fish in this region, if not in California as a whole, is the Delta Smelt.
The Delta smelt is the poster child of all that is wrong in the Sacramento-San Joaquin Delta.
This year, the number of Delta smelt was essentially zero; i.e., it is either extinct or very close to it. Why is this important? Often you will hear things like, "we cannot do such and such because it will endanger the Delta smelt..". Delta smelt are often at the root of water policy in California, and particularly, discussions about shipping water from northern California to the southern portions of the Central Valley for irrigation of crops, and further south, to the Los Angeles area for myriad uses.
Delta smelt are found ONLY in the Sacramento-San Joaquin delta and no where else in the world. This means that by definition, they are globally rare, nationally rare and even locally rare. This is important because of the Endangered Species Act, which basically says that we have to be very careful about doing anything that can cause further harm or threat to organisms which are endangered. It is relatively easy for most people to appreciate the magnificence of a bald eagle or other charismatic organism, and the threat of such a species going extinct alarms people to take action. They are willing to take action to help the recovery of such a species. The Delta smelt is protected by the same laws but is far less charismatic. Many people ask "What good is the Delta smelt?". The Endangered Species Act does not require that a species be pretty, charismatic or even good for anything. The Act recognizes the right of such species to simply exist.
That said, the case of the Delta smelt is far more complex. The Delta smelt is not nearly extinct due to overfishing -- no one fishes for Delta smelt. It is near extinction because of the collapse of the ecosystem in which it lives, namely the Delta, and the causes of that collapse are abundantly clear: we (humans) have irreparably harmed the Delta ecosystem. The rapid decline of the Delta smelt is a symptom of the damage we have done. The problem now is that it is unclear how to slow, stop or even ideally reverse that damage. Some people would like the Delta to "go back to the way it was", i.e., its original form. That cannot happen. The original delta was a sea of tule grases, marshes and wetlands extending from Sacramento down to the East Bay. That land has been dyked, drained, leveed, farmed and constructed on. Millions of people now call that area home and it is simply not going to happen that all those people, businesses, etc are going to leave. So, the real question becomes: can we make the Delta healthy, if different than its original form? This is a multi-billion dollar questoin.