The Stanislaus River is under invasion, and Congressman Jeff Denham (R-Turlock) wants to do something about it.

So who are these pesky invaders? Non-native fish.

Last week, Denham introduced H.R. 270 or the Stanislaus River Native Anadromous Fish Improvement Act, a pilot program to protect California's native salmon and steelhead fish populations from consumption from non native fish, mainly the striped bass.

“Through the work of fishery agencies and the broader scientific community, it has become clear predator fish are greatly impacting the recovery of salmon and steelhead fish on the Stanislaus River,” said Denham.

The pilot program would  be a collaborative effort between the U.S. Bureau of Reclamation, the Oakdale Irrigation District and the South San Joaquin Irrigation District. The program would require rigorous, scientific-based monitoring of non-native consumption of juvenile salmon and steelhead fish populations.

Denham said the federal government has been allocating too many efforts in attempting to save native fish, without actually looking at the non-native fish that are consuming them.

“It’s absurd to keep spending millions to try and save native fish while non-natives devour nearly the entire population,” said Denham. 

The striped bass, which was introduced in the Central Valley waters, has become widely popular with the sport fishing community. However, according to some experts, they have had devastating effects on the native fish populations.  According to estimates by the California Department of Fish and Game, striped bass may consume upwards of 25-50 percent of winter and spring-run Chinook salmon.

However, not everyone agrees with Denham's that the striped bass are the major cause of declining populations of juvenile salmon and steelhead populations.

Advocacy group Water 4 Fish maintains that striped bass and native fish have successfully coexisted in the Delta for more than 100 years, and the decline of native fishes did not begin until pumping and agricultural extractions reached unsustainable levels.

In 2011, the Coalition for a Sustainable Delta, a  not-for-profit organization, came to a settlement with the California Department of Fish and Game after they sued the state department, claiming there was mismanagement of striped bass that was eventually leading to the demise of native salmon and steelhead population. The settlement included a proposal that would require the California Fish and Game Commission to reduce numbers of one of the Delta’s most popular game fish.

The proposal was unanimously rejected by the Commission early last year.

 If passed, Denham's pilot program will take place solely on the Stanislaus River and last for the duration of five years.

“This pilot program will help us take action to save the threatened native fish and advance our collective knowledge of controlling non-native predatory fish in California,” said Denham.