their state populations grew. Hurricanes and floods prompted Florida to construct an elaborate water supply and flood control system in the 1930s that diverted much of the naturally flowing water away from the Everglades, shriveling the wetlands to a fraction of its natural size.
In California, floods and growing water supply needs spurred development of the federal Central Valley Project in the 1940s and the State Water in the 1960s. But those projects, drawing their fresh water supplies directly from the Delta, also added to the many other manmade environmental stresses–such as Delta farming that dates back to the 1880s–which foreshadowed a long, downward trend in many fish species.
Both states put together surprisingly similar strategies to deal with the situation–restore natural habitats and let the species respond.
“In the early 1990s,” says South Florida’s Smith, “we worked to generate interest and secure funding.”
An early dust-up with sugar cane farmers in Florida over phosphorus in the Everglades was resolved with better irrigation practices and acquisition of land for constructed wetlands. In 2000, Florida in partnership with the federal government unveiled an $8.5 billion, 30-year program focusing on land acquisition and development of new water storage solely for environmental uses. The goal was to recreate historical water flows to revive the ecosystem. Forty thousand acres of reconstructed wetlands are already in place for storm water treatment, about half the eventual goal.
Close tabs are kept on shrimp, oysters and lobster in Florida Bay and endangered populations of a species of sparrow and panthers in the Everglades themselves. So far, signs of revival are encouraging.
Just like in Hollywood, nothing seems to breed success like success. The state of Florida is now preparing a $1.8 billion bond issue to speed the development on a variety of Everglades projects, ahead of the schedule outlined in the restoration plan.
While the timeline for California’s Delta restoration is similar, the outcome so far is more equivocal. Native species had faced conditions that included overfishing, invasive species, toxic runoff from farms and cities, water diversions to the Bay Area, and altered flows due to state and federal water projects. Hammered by drought in the late ‘80s and early ‘90s, winter-run Chinook salmon and Delta smelt were both placed under protection of the Endangered Species Act. Protective measures greatly constricted water deliveries to much of California and precipitated a crisis in the Delta.
Federal and state resource agencies, along with urban, agricultural and environmental interests, came together and approved the Bay-Delta Accord in 1994 to stabilize the situation. A year later, the CALFED Bay-Delta Program was formed, with a final program formalized in 2000. Like the Everglades restoration, the Delta effort was expected to take 30 years and cost billions. The achievements included an innovative Environmental Water Account launched to address fishery needs while restoring a measure of reliability to state and federal water deliveries. In conjunction with the federal Central Valley Project Improvement Act, state and federal budget allocations, water user fees and three water bonds, roughly $2 billion was committed to ecosystem restoration.
By many measures, the effort has been successful, especially for salmon, which migrate through the Delta on the way to their traditional spawning grounds.
“The best test of our restoration programs will be to see how the fish weather the next drought. But I feel strongly that these actions have improved conditions–and their chances,” says Jim Smith of the U.S. Fish and Wildlife Service, a project leader on the Sacramento River who began as a fish-counting biologist.
Small dams on tributaries have been removed and replaced with distribution systems that better serve water users while creating habitat for fish.
Miles of habitat have been opened up on streams like Butte, Mill and Clear creeks. Cold-water releases from Shasta Dam have provided better spawning temperatures. The gates at a diversion dam in Red Bluff were opened for most of the year to allow better fish passage and ward off predatory species. Spawning gravels have been replenished and water diversions screened to keep fish out. Most of these projects required financial assistance from Metropolitan’s Southern California ratepayers.
Among the focal points were winter-run salmon, so called because they return from the Pacific in the winter to their upstream spawning grounds. young fry emerge in early to mid-summer heat in the upper Sacramento River Valley, but need water 56 degrees or cooler to survive. Back in 1991, when they were first protected, the run had dwindled to a mere 188 spawners–adults that return to their native river waters to reproduce. By last year, numbers had rebounded to about 8,000 and Smith expects substantially more based on 2005’s preliminary counts.
Other species that have prompted concern, such as spring-run salmon and steelhead trout, also seem to be responding to the improved conditions. On one stream alone, Butte Creek near Chico, improvements developed in a partnership involving Metropolitan, the local agricultural water agencies, and the federal government were able to increase spring-run adult populations by nearly 10,000 fish. And the backbone of the state’s salmon populations–the fall and late-fall runs–continue to number in the hundreds of thousands, setting historic records.
In the Delta itself, the story is more complex.
Only a few years ago, there was serious discussion about de-listing the rebounding Delta smelt from ESA protection when a new, unexpected decline in their population measurement index set in beginning around 2002. By early 2005, the Delta smelt index hit an all-time low and levels of striped bass, threadfin shad and longfin smelt were also in perilous decline.
A state-federal resource team assessed the situation and developed an action plan to address it. Initial suspicion fell on three potential causes: a major change in the Delta food chain; new pesticides that are more toxic to fish; operational changes at the state and federal water projects that were put in place, ironically, to protect fish. The current problems of the pelagic (or open water) fish in the Delta may be the result of one or a combination of all three factors.
As with the best Hollywood sagas, this Delta development has a long back story–and often takes unexpected plot twists.
The Delta is an extremely porous environment, vulnerable to accidental or intentional introduction of alien species. In 1986, an Asian clam was introduced to the estuary, most likely through a cargo ship discharging its ballast water into the San Francisco Bay. The thumb-sized clam found the estuary a welcoming new habitat. Like extras in a DeMille epic, in a few short years, the clam had grown to a cast of thousands, reproducing to an average of 2,000 per square meter, and as many as 48,000 per square meter in Suisun Bay midway between San Francisco Bay and the Delta.
It feasted upon a microscopic zooplankton called eurytemora–unfortunately, the favored food of the Delta smelt. At the same time another introduced zooplankton, pseudodiaptomus, appeared in the estuary and became a fallback food source for the smelt and, presumably, other small fish species in the Delta.
In nature, everything is either prey or predator and usually a bit of both. Soon another variety of zooplankton–limnothiona–appeared in the estuary, and preyed on competing pseudodiaptomus. And a toxic algae, microcystis, became more prevalent in the Delta, blooming with lethal regularity. For the past 15 years, pseudodiaptomus has been on a steady decline due to these adverse conditions. As its primary food source disappeared, Delta smelt have declined.
While the Delta story may not yet have the typical Hollywood happy ending, this is one movie you don’t want to walk out on. The estuary is too vital an environmental resource, the water too crucial to the California economy. The challenge will be to sharpen the science, refocus the mission and, perhaps, better woo the general audience to an appreciation of just how important success in the Delta is for all Californians.
