Scientists have estimated that over the course of Earth's history, anywhere between 1 and 4 billion species have existed on this planet. Be it through disease, genetic obsolescence, over-predation or any number of other factors, the overwhelming majority of these species are now extinct. Of these billions of species, roughly 50 million still survive into the modern era. While these numbers are certainly extreme at first glance, it serves as proof that extinction, while a sad occurrence, is a part of life for all living things.
That all changed with the birth of the federal Endangered Species Act, 40 years ago Saturday.
The law says unequivocally that it is the official policy of the United States not to let any species go extinct, no matter what. That simple but powerful declaration resulted in my many years of recording the biology and decline of our native fishes.
The Endangered Species Act was used timidly at first, mainly for protection of spectacular species such the bald eagle and the gray wolf. But it did catch the attention of fisheries agencies. They funded my exploration of northeastern California, where few fish biologists had sampled since the early 20th century.
My graduate students and I searched in particular for three species we suspected were in trouble: Modoc sucker, rough sculpin and bull trout. We found the Modoc sucker was indeed endangered, but easy to protect, while the rough sculpin was reasonably secure. The bull trout, alas, we found to be extinct or nearly so in California. One of my students made the last recorded catch, on the McCloud River in 1975. Our 1970s surveys became a baseline for the status of fishes in one of the most interesting parts of the state.
As an untenured professor then, I thought it bit risky to base a career on finding rare fish. So I also undertook a study of Delta and longfin smelt, which at the time were two of the most abundant fish in the Sacramento-San Joaquin Delta. These were routine life-history studies to fill some knowledge gaps for a book I was writing on California’s fishes.
The studies lead me to start, in 1979, a monthly sampling program to keep track of the populations or smelt and other fish in nearby Suisun Marsh. Just a few years later I noticed a dramatic in our smelt counts. I checked other regular fish surveys (mostly for striped bass or salmon) and the same pattern appeared. The data led the U.S. Fish and Wildlife Service in 1993 to list the Delta smelt as “threatened,” affording it special protections under the Endangered Species Act.
The Delta smelt joined the Sacramento River winter run chinook salmon on the federal threatened list, followed by other fish native to Central California. Water policy and politics would never be the same.
I wish I could say that once the Endangered Species Act kicked in, everything got better for California fishes. But it hasn’t. In fact, I have been recording a statewide decline of most native fishes, largely as the result of dams, diversions, water export pumps in the Delta and other manipulations of our water system. Meanwhile, climate change is warming the rivers and accelerating the declines of already depleted fish populations.
On the positive side, the ESA has prevented more extinctions of our native fishes and generated a lot of valuable information about them. We know better than ever their plight, causes of their decline and potential remedies.
With other researchers, I have just completed detailed accounts of the biology and status of more than 60 native fishes – all potential candidates for listing under the federal and state endangered species laws. The soon-to-be-released study for the state Department of Fish and Wildlife summarizes information gathered from biologists working all over California.
Most of our recommendations for preventing extinctions call for more and better water for the fish, or at least for protecting existing water they depend on. Funny how it almost always comes down to fish needing water.
The Endangered Species Act sets a high standard in this regard because it not only forbids extinction; it also mandates recovery of each species to a more sustainable state. The law takes a high moral ground when it comes to our treatment of other species.
Our treatment of native fishes and their habitats has been rather shabby, despite the efforts of our underfunded agencies. We can do better. We can measure up to the high moral standards we as a nation established in the Endangered Species Act of 1973. The fate of the fishes found only in California depends on it.
Peter Moyle is a fisheries biologist at the University of California, Davis, and is associate director of the Center for Watershed Sciences at UC Davis.