Splittail and salmon losses at pumps could be 5 to 10 times ‘salvage’ numbers

Tracy Fish Salvage Facility

by Dan Bacher

The loss of millions of Sacramento splittail, a native minnow, and tens of thousands of Sacramento River spring-run chinook salmon continues at the state and federal water export pumps on the Sacramento-San Joaquin River Delta.

A total of 7,511,121 splittail and 25,128 salmon were “salvaged” at the state and federal pumps between May 1 and June 14, 2011 alone, according to Bureau of Reclamation data.

However, this number of fish “salvaged,” as alarming as it is, does not show the actual loss of fish in the state and federal water export facilities. The overall loss of fish species in the pumps is 5 to 10 times the “salvage” counts, according to “A Review of Delta Fish Population Losses from Pumping Operations in the Sacramento-San Joaquin River Delta,” prepared by Larry Walker Associates in January 2010 for the Sacramento Regional County Sanitation District (http://www.srcsd.com/pdf/dd/fishlosses.pdf).

The Walker Associates study cited a 1996 report by DWR and DFG concluded that for every salmon salvaged at the fish protection facilities, more than three are lost to predators or are lost through the fish screens. The report also stated that these loss rates “demonstrate a serious problem.”

“The same 1996 report stated that over a 15-year period (1979 to 1993), 110 million fish were reported to have been salvaged at Skinner Fish Facility, the fish protection facility at the SWP,” the report stated. “These salvage statistics greatly understate the total number of fish entrained, since they do not include the number of fish lost to predators or lost through the fish screens. In fact, recent estimates indicate that 5-10 times more fish are lost than are salvaged, largely due to the high predation losses in and around water project facilities.”

In 2008, Wim Kimmerer, a prominent ecologist and Delta researcher, estimated that approximately 30 times more delta smelt are entrained than are salvaged.

“In 2008, the United States Fish and Wildlife Service (USFWS) also reported that high entrainment rates during winter months are suspected as a contributing cause of the early 1980s delta smelt decline and the pelagic organism decline or ‘POD.’ The POD refers to the record low numbers of four species of fish that occupy the open waters of the upper San Francisco Bay estuary,” the report noted.

Based on the Larry Walker Associates data, the actual numbers of juvenile splittail lost in and around the pumping facilities could have been as high as 37,555,605 to 75,111,210 during just this six week period!

Again, based on this data, as many as 125,640 to 251,280 juvenile salmon could have been lost around the pumping facilities during just this six week period!

Even if we accept the conclusion of the report by DWR and DFG that concluded that for every salmon salvaged at the fish protection facilities, more than three are lost to predators or through the fish screens, we end up with 75,384 salmon that were lost, in addition to mortality among the salvaged fish.

Of course, the word “salvage” is a euphemism, since anywhere from 90 to 95 percent of these fish are lost to predators and other factors after being returned to the Delta by truck. However, the important point is that the actual numbers of fish killed by the facilities that pump water to corporate agribusiness and southern California water agencies are much greater than the “salvage” numbers reflect.



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