California’s Altered Rivers

Some of our CART students after releasing juvenile Chinook salmon in the San Joaquin River watershed

A major focus for the Institute in planning the Fresno Aquarium are the important messages we want to impart to the general public.

Of course, we're pro-fish. We love fish! We also love to eat and are acutely aware that agriculture in the San Joaquin Valley has been, and continues to be, blamed for the demise of native and endemic* freshwater and anadromous fish, plant and invertebrate riparian species that formerly existed in abundance throughout the Sierra Nevada watershed.

While it is true that farming in our region has necessitated the construction of an irrigation system that has been the envy of the world and has altered historic natural flows of rivers and streams impacting native species, it is also true that non-native species that were intentionally introduced by the State of California throughout the 20th century have impacted both native and endemic species in significant ways.

Our ability in the 21st century to reverse the decline and even extinction of California native and endemic species relies not on simply providing them with adequate water, but also removing all or a significant number non-native predators and competitors that now exist throughout the watershed. Such a task is likely impossible.

Even after facing this reality, one of the best messages the Fresno Aquarium can disseminate to those people in and beyond our Valley is that all is not lost when it comes to the San Joaquin River and the Sacramento-San Joaquin River Delta. The introduced non-native species need not be labeled "bad" or "good" - they are here and are now part of our highly-altered riparian ecosystem. There is nothing wrong with advocating for the control or management of certain less-desirable species, but it is unrealistic to expect a return to pre-Gold Rush era conditions for our watershed.

The incredible and complex freshwater story of central California is filled with past decisions and punctuated by monumental feats of engineering by previous generations that continue to benefit every person living in California today. San Joaquin Valley agriculture feeds the world and is vital to our nation's food security. Our message should be that human beings and the environment can and do co-exist. Fish can thrive in a river that is also used by people. It's not a winner-take-all game.

*Endemic is defined as a species that was only found in one place at the time they were first discovered. It does not mean a species can’t survive if moved outside of that location as long as its food and water quality needs are met and it is adequately protected from predators.