Federal biologists have determined that water deliveries through the Delta could drive several runs of salmon, steelhead and green sturgeon to extinction.
The biologists are continuing to investigate whether the loss of salmon is jeopardizing a population of killer whales off the West Coast.
Those findings were contained in a 450-page analysis of water operations from dams on the Sacramento, Feather and Trinity Rivers through the massive pumps near Tracy.
The document, posted on the National Marine Fisheries Service Web site Thursday, did not include measures that biologists will insist be taken to prevent spring- and winter-run chinook salmon, Central Valley steelhead and green sturgeon from going extinct.
Those measures are due to be released in early March.
Water agencies, fearing drought and hit last month with restrictions to protect Delta smelt, are bracing for more bad news when the salmon measures are imposed.