Dec 28, 2000

Native Fish Still Common in Natural Streams, Scarce in Canals

Native resident fish species such as the Sacramento sucker and tule perch are still commonly found in streams of the Sacramento River Basin in Northern California according to a recent U.S. Geological Survey (USGS) report. Native fish species are least often found in waters impacted by agricultural drainage, where introduced species such as bass, sunfish, and catfish tend to dominate. Native fish species are not as common in the San Joaquin River Basin to the south, where introduced species tend to dominate the streams. The USGS report attributes the abundance of native resident fish species in the Sacramento River Basin at least partially to water management activities that favor the delivery of water through natural streams rather than diversions into canal systems.

"The conditions in the Sacramento River Basin may provide a useful comparison case for ongoing native fish species restoration efforts around the Nation," said Jason May, primary author of the report. "Relations between native fish species and their environment in the Sacramento Basin are especially relevant to the San Joaquin River Basin and other highly modified river basins in the western United States."

The report is based on a study of 22 stream sites in the Sacramento River Basin during 1996 to 1998 and is a part of the USGS’ National Water-Quality Assessment (NAWQA) Program. Fish monitoring conducted as part of the NAWQA Program has provided valuable information to gauge the ecological health of streams in the Sacramento and San Joaquin valleys and to help assess ongoing restoration efforts within California’s Central Valley.

"The protection of native resident fish communities in the Central Valley is important in maintaining California’s biodiversity. Also, monitoring these communities can provide important information regarding the effects of actions intended to restore or protect fish species such as Chinook salmon and steelhead on general stream health" May said.

SOURCE: U.S. Geological Survey