The Index, a scientific measure of relative abundance, was only 26 in the 2005 survey, according to Chuck Armor, operations manager for the DFG’s Bay-Delta Branch. This contrasts to 74 in 2004 and 210 in 2003. Just 10 years before in the fall of 1995, the index was 899.  

Delta smelt, a listed species under the state and federal Endangered Species acts, is a small and relatively obscure fish. Although it doesn’t have economic importance like larger recreational fish such as striped bass, sturgeon and steelhead or commercial species including king salmon and Dungeness crabs, this fish serves as a vital indicator species of the health of the California Delta.  

The Delta smelt’s significance lies in that it lives entirely within the confines of the estuary, in contrast with other fish that migrate to and from the Delta on spawning and feeding migrations. Changes in Delta water quality, water export regimes and the food chain impact it more directly than other species.  

The Delta is the largest and most significant estuary on the Pacific Coast of North America. The food chain collapse in this estuary will have a far reaching impact on salmon, Dungeness crab, striped bass, sturgeon and other fish populations along the coast.  

This unique fish has an unusual life history relative to many fishes, according to William A. Bennett (Critical assessment of the delta smelt population in the San Francisco Estuary, California. San Francisco Estuary and Watershed Science. Vol. 3, Issue 2 (September 2005), Article 1).  

‘“Smelts in the genus, Hypomesus, occur throughout the Pacific Rim, have variable life history strategies, and are able to adapt rapidly to local environments,” explained Bennett. “By comparison, delta smelt has a tiny geographic range being confined to a thin margin of low salinity habitat in the estuary. It primarily lives only a year, has relatively low fecundity, and pelagic larvae; life history attributes that are unusual when compared with many fishes worldwide.”  

Not only is the Delta smelt population index for 2005 the lowest ever on record, but the longfin smelt, a relative of the Delta smelt, continued to decline. The longfin smelt abundance index was 129 in 2005, the second lowest ever recorded. The only year when the index was lower was in 1992, when DFG recorded an index of 76.  

The longfin smelt, before the massive diversions of subsidized water to San Joaquin Valley agribusinesses and southern California, was an extremely abundant species. In 1967, before the state water exports shifted into full gear, the abundance index was 81,790!  

The striped bass and threadfin shad abundance indices were better in 2005 than in 2004, but these species are still in very serious trouble. The striped bass index was 121 in 2005, compared to 53 in 2004, 108 in 2003 and 71 in 2002 and 731 in 2001. In 1967, when the striped bass fishery was at its highest ever population, the index was 20,038.  

The threadfin shad population, an introduced species whose decline has concerned scientists because it is such a hardy and adaptive species compared to more sensitive fish like the Delta smelt, showed an temporary upturn with an index of 2866 in 2005, compared to 1301 in 2004, 1956 in 2003 and 1753 in 2002.  

The last good year for threadfin shad before the Delta crash was in 2001, when the index was 14402. Because of this decline, the fish has been very difficult to obtain for bait by commercial fishermen.  

Last spring, a special team of federal and state scientists announced a dramatic downturn in four species – Delta smelt, longfin smelt, threadfin shad and juvenile striped bass – over a four-year period. In their studies and surveys, they also reported alarming declines in plankton species that these smaller fish – and in turn larger game fish – depend upon.  

The scientists believe that three factors may behind the Delta crash: (1) invasive species such as the Asiatic clam; (2) toxics, including new pesticides and herbicides; and (3) changes in water export regimes through the state and federal pumps. Fishery conservation and environmental groups have emphasized that the key change in the Delta has been the dramatic increase in water exports through the state and federal pumps. In fact, three of the four last years were record water export years.  

More recently, a report by a nine-member team of independent researchers, said that the decline may not have been caused by any new factor, but instead was part of a decades-long decline.  

“The currently identified step change may simply be one of a series of such events,” the report stated. “The question of whether such as shift occurred – or whether the apparent shift is simply part of the decline that has been occurring over decades – is important.”  

John Beuttler, conservation director of the California Sportfishing Protection Alliance, emphasized that the Delta crash could lead to a “complete loss” of the striped bass fishery that anglers prize so much.  

“The DFG data shows no good, healthy year classes of juvenile striped bass in over 20 years,” said Beuttler. “Without healthy year classes of juvenile fish, you eventually won’t have an adult fishery. And with the termination of the one program that was the salvation of the of striped bass fishery, the Fishery Foundation of California’s Pen Rearing Program, there is nothing in place to prevent the striped bass decline from becoming a collapse.”

  Losses of striped bass at the pumps were mitigated from 1991 to 2002 when the pen-rearing program raised striped bass in mobile pens for two years until they were large enough to escape predators and unscreened diversions before being released back into the Delta. Beuttler believes the program is at least partially responsible for a dramatic increase in adult striped bass numbers from 750,000 to 1.5 million in several years – at the same time that juvenile index numbers were steadily declining.  

Unfortunately, the pseudo-scientists of NOAA Fisheries (aptly nicknamed NO Fisheries by Zeke Grader) asked the DFG to stop the program. In reasoning that defies all known science, the federal bureaucrats reasoned that increasing striped bass numbers was somehow a big factor impeding winter run chinook salmon recovery, even though the two species had coexisted with no problems for over 100 years.  

“With the decision to terminate the program, we no longer have programs to mitigate for the losses of hundreds of thousands of young of year stripers in the pumps every year,” concluded Beuttler. “The salvaged pen-reared population contributed much more to the striped bass recovery than the DFG ever gave credit for. How else – other than divine intervention - could you explain a population increase of adult striped bass by 750,000 fish in several years?”  

Just as alarming as the crash of Delta smelt, threadfin shad and juvenile striped bass populations is a dramatic decline in the adult sturgeon population in the Bay-Delta Estuary. Since a 1998 peak of about 144,000, the abundance of California's legal-sized white sturgeon has declined due to a variety of factors such as poor spawning success, impediments to migration, entrainment, and legal and illegal harvest. “Information developed in November 2005 suggests that the abundance of legal-sized white sturgeon is now at a 50-year low of about 10,000 fish,” according to a recent press release from the California Department of Fish and Game.  

The latest DFG data documenting the decline of Delta fish makes it even more urgent that we stop the South Delta Improvement Project, a state-federal project designed to expand the water export capacity of the state and federal pumps. We cannot allow water exports to corporate agribusiness and southern California to increase when all indications are that the Delta ecosystem is in a state of unparalleled collapse!  

More articles by Dan Bacher