Extra river water is expected to flow into the Bay this winter, which could help relieve growing salt levels in the estuary, after a judge ruled that water exports must be slashed from the Southern California supply to protect an ailing species of tiny fish.
A report by the U.S. Fish and Wildlife Service, which downplayed dangers to delta smelt from Central Valley water pumps, was ruled “unlawful and inadequate” in May by U.S. District Judge Oliver Wanger.
The ruling should be a boon to the Bay, as wildlife is already expected to struggle this winter because of toxins and oil from 58,000 gallons of shipping fuel that leaked out of a container ship in early November. The ruling also led Southern Californian water agencies to warn of an impending water crisis, but it was welcomed by Northern Californian environmentalists who say water exports are killing the delta’s ecosystem.
“Judge Wanger’s order for more responsible operations of the delta pumps comes in the nick of time for the delta smelt and the delta ecosystem,” Bay Institute scientist Tina Swanson said in a statement.
Large water pumps pose a danger to fish species, such as the short-lived delta smelt, not only killing them within the pumps but causing habitat changes, according to a report by Frederic Nichols of the U.S. Geological Survey.
The extra river water is vital to wildlife in the Bay. Fresh river-water reduces salt levels and helps native species breed, according to UC Davis Bodega Marine Laboratory professor Gary Cherr. Cherr said eggs laid by Pacific herring are unlikely to hatch in salty conditions, and that the baitfish are important because they’re eaten by bigger fish, shorebirds and sea lions.
Dry winters also help push up salt-levels in the Bay, according to Cherr.
A dry winter is likely this year, according to National Weather Service meteorologist Steve Anderson. “We have a prevailing La Niña condition,” he said. “Statistically, La Niñas are dryer than normal.”
Mussels and other filter-feeding critters are important sources of food in the Bay for other wildlife. Fish and Game tests in late November found elevated levels of cancer-causing chemicals in mussels called aromatic hydrocarbons, which are found in shipping fuel.