upper waypoint

The Challenges to Saving California's Delta Smelt

Save ArticleSave Article
Failed to save article

Please try again

Delta smelt is an endangered fish that lives in the San Francisco Bay-Delta. (Peter Johnsen/US Fish and Wildlife Service)

When a coalition of California and federal agencies announced a new Delta Smelt Resiliency Strategy last week, the ambitious plan to save the region’s nearly extinct fish grabbed headlines.

But whether most, or even parts, of the comprehensive program can realistically put in place the changes needed to rescue this endangered native species is another question.

“I understand what they are aiming at doing and why. But how achievable it is, and whether or not it will result in the desired outcome, is a different matter,” said Richard Connon, a toxicologist at UC Davis, who studies the impacts of contaminants on smelt and other fish.

From eliminating invasive aquatic weeds and increasing Delta water outflows to adding sediment to create more turbidity, the strategy is long on vision but potentially short on execution, he said. Take, for example, weed control in the Sacramento-San Joaquin Delta. It’s what Connon calls a “double-edged sword,” since physical removal of the plants is all but impossible, while the use of herbicides can have dangerous blowback effects such as killing off the phytoplankton that smelt need to feed on.

“This document was just an outline of what they’re proposing to do, rather than a step-by-step detail on how they’re going to do it,” Connon added. “Keeping up with the growth of these weeds is almost impossible. They haven’t provided sufficient data on how it’s going to be done.”

Sponsored

The plan, announced last Tuesday by the California Natural Resources Agency, is to be implemented by California’s Department of Water Resources, Department of Fish and Wildlife, and Division of Boating and Waterways, along with the U.S. Fish and Wildlife Service and Bureau of Reclamation. It addresses what it calls “a variety of methods” to revive smelt, which are currently at their lowest ever levels due to drought, increased water exports, predator fish, pollution and other conditions.

Among numerous goals, the plan calls for:

  • Releasing water from Sacramento Valley farm fields into the Yolo Bypass to increase the production of the zooplankton on which smelt feed.
  • Increasing outflows from the Delta to generate more brackish water.
  • Reoperating salinity control gates in Suisun Marsh.
  • Improving spawning conditions by adding more sand and gravel.
  • Reducing toxic algae blooms that are harmful to smelt.
  • Restoring 5,500 acres (2,225 hectares) of tidal wetlands.
  • Reducing stormwater contaminants polluting the estuary.

Due to be carried out over the next three years, parts of the strategy could face significant opposition, including potential lawsuits by farmers in the Central Valley demanding that more water, not less, be channeled to them rather than flushed out to sea to help a fish that is largely doomed anyway.

State officials are confident the approach is the right one. “With the best available science as our guide, we’re moving fast to improve conditions so that more young delta smelt survive this year and reproduce,” said California Department of Fish and Wildlife director Charlton H. Bonham in a statement.

But Connon isn’t the only one who doubts the efficacy of the plan. A spokesman for the U.S. Bureau of Reclamation, Shane Hunt, said the project appeared overly ambitious in scope. “We’re fairly confident we’ll get some water” to release as outflow, he told the Sacramento Bee, “but I don’t think we’ll get anywhere close to the top end of this range that’s in this document this year.”

An even harsher critic is Tom Cannon, a retired fisheries consultant and current adviser to the California Sportfishing Protection Alliance, who said the strategy offers too little too late, and is too unrealistic to have any significant impact. Foremost among its problems: “The plan has no way of getting the water.”

“Right now the agencies can mandate that we need 8,000 instead of 7,000 cubic feet of water per second [225/200 cubic meters] as outflow (into the San Francisco Bay and Suisun Bay), which is critical for smelt survival,” said Cannon. “But the plan says they’re not going to take people’s water and the farmers aren’t going to let them take their water, so they have no way of getting it unless they buy it, and they can’t get the money. You think a Republican Congress will give them money to buy water for the smelt to let it go into the ocean? They’d all laugh, 250 of them.”

Other individual parts of the strategy also don’t hold up, he said. For one, releasing water from the Sacramento Valley into the Yolo Bypass at this time of year would kill the smelt due to high summer temperatures (smelt can survive only in water in the low 70s F [low 20s C]). Second, the act of pumping turbid, sediment-rich Delta water south and replacing it with clear, warm reservoir water counters the goals of the strategy.

“They suck all of the larvae out of the Delta, all of the plankton they eat and all of their habitat, and they replace that water with reservoir water” that allows in lots of sunlight, encouraging the explosive growth of weeds that they’re trying to get rid of, said Cannon.

Some positive points stand out in the plan, such as the return to using salinity control gates to allow freshwater into Suisun Marsh while keeping saltwater out, and managing stormwater discharge to control the contaminant load into tributaries and rivers. “If they can actually control the amount of stormwater, hold it so contaminants can degrade before entering waterways, or divert it to wastewater treatment plants, that will diminish the contaminants that enter the Delta and improve the water quality at spawning sites,” said Connon of U.C. Davis.

Over the past 20 years, biologists have considered smelt to be the canary in the coal mine: a functionally extinct species that no longer serves any real ecological function other than as a warning for the entire Delta ecosystem. With the drought, their population crashed dramatically, raising the question of whether it is already too late to save them – and whether proposals such as the strategy released last week, without more structural changes to California’s water distribution rules, are convincing any longer.

Sponsored

“It is a public relations piece, a strategy to satisfy the Endangered Species Act,” said Cannon. “They have to do something so they come up with this plan, but it’s not going to help the smelt. If they want to save the smelt, either release more from the reservoirs or cut back the [water allocations to] farmers.”

lower waypoint
next waypoint