Facing extinction: California fishes
by Peter Moyle and Jason Baumsteiger At least two species of California fishes appear to be facing imminent extinction in the wild: delta smelt and winter-run Chinook salmon.
These species could join about 57 other North American fishes declared extinct.
As far as we know, none of these fish were ever officially declared extinct for the first time by state or federal agencies.
An exception may be the thicktail chub, which was declared extinct by Mills and Mamika in an administrative report by the California Department of Fish and Game, 23 years after the last fish was caught.
How do we know when a species is extinct?
Ricciardi and Rasmussen modeled the extinction trajectories for all the aquatic fauna in North America and estimated extinction rates of 4% per decade “which suggests that North American freshwater ecosystems are being depleted of species as rapidly as tropical forests (p. 1220).” Further studies by Howard et al. for the aquatic fauna of California support this conclusion as does the study of Grantham et al., which shows a disconnect between fishes needing protection and protected areas.
In conclusion, the best strategy is not to let any fish species go extinct.
If a fish species does go extinct, despite our best efforts, then funds and water used to keep the species going should be redirected towards keeping other species from following the same extinction trajectory.
But to avoid spending scarce conservation dollars on species that have already gone extinct, we need a policy in place that provides a pathway for declaring a species officially extinct.
Missing the boat on freshwater fish conservation in California.