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Wising Up on Rehab
"An ecosystem shaken to its roots," is the way editor Bill Jordan of the University of Wisconsin described the Bay-Delta watershed at the March 1999 State of the Estuary Conference. Over 600 earnest folk hunkered down in the Palace of Fine Arts auditorium for the event and watched images of the Estuary splash and seep across the slide screen-visions of long-lost ecological exuberance, comparisons of the snake of a river meander or marsh slough pre- and post- "restoration," snapshots of near-extinct thistles and minnows, and charts depicting progress, failure and uncertainty.
By the time the conference wound to a close three days later, one thing had become very clear: though the idea of "restoration" has the power to make us all fired up and "dewy-eyed," as Jordan put it, the practice is a far less straightforward endeavor. The government may be spending billions on restoration to soothe the smoldering California water wars, but there's no guarantee that unhitching a few of the shackles binding the estuarine workhorse is going to make it break into an joyful gallop.
The shackles are indeed daunting. First speaker Matt Kondolf of U.C. Berkeley painted a stark picture of damage done to the ecosystem - the dams, reservoirs and levees controlling its spill from the Sierra to the ocean. Only one of nine rivers - the Cosumnes - runs free; only three of dozens of creeks have healthy populations of spring-run Chinook salmon while less healthy salmon venture forth from hatcheries that Kondolf likened to "methadone maintenance programs." Reservoirs in the Sacramento and San Joaquin River basins are so extensive they can now store more water than actually runs off. Real restoration of this system would require removing whole dams from the headwaters and whole cities from the floodplains.
Perhaps that's why conference organizers chose the theme of "rehabilitation," rather than restoration - a choice second speaker Jordan scolded them for. "It's a mistake to dumb down what we think our vision is, you have to look at the power of these words to generate social energy," he said. "Rehabilitation means fitting or refitting something out for use, it's so unspecific it doesn't mean very much. But everybody knows what restoration means, it means putting something back the way it was, going back to something better. We can come from the top down, with money from the government, with expertise from the universities, but it's not going to work without grassroots social support."
Whatever the word, putting it back the way it was, using the natural historic landscape and ecological processes as a guide, was the theme of speaker after speaker at the conference. Hydrologist Phil Williams donned an imaginary white coat and diagnosed the Estuary as suffering from many pathological conditions including blocking (dams), narrowing (channelizing) and hardening (levees) of the arteries (rivers), persistent bleeding (exports), flatlining of the rivers (no more peaks and pulses and floods), and anemia (inability to capture sediment). He called the purchase of floodplain lands without making provisions for creating flood flows "cosmetic restoration" and said it was time to retrofit California's "obsolete" water project infrastructure and rethink operation of the dams - many of which operate based on outdated 1940-50s policies and science. "It's time to free ourselves of the legacy of decisions made 60 years ago," he said, calling for serious evaluation of the potential to remove some major dams, possibly through the extension to all dams of the current federal relicensing process (FIRC).
The power of dams and levees to shoot water straight through the Estuary, instead of allowing it to sit around for while, was the theme of the following talk, by U.C. Davis' Jeff Mount. Mount said it used to take weeks for water to move through the San Joaquin River system, and now it takes days - largely because the river has been separated from plains where it used to flood, meander and deposit sediments and nutrients. "The best restoration efforts done within the basin will be those that enhance residence times," he said, citing the productivity of the Yolo Bypass where water now floods 59,000 acres for two weeks instead of a few days, spurring growth of aquatic plants and animals and fattening fish.
When water sits around for while, it has more time to seep down and replenish groundwater aquifers and speaker Neil Dubrovsky of the U.S. Geological Survey argued that it's been a mistake to separate management of surface water from groundwater for so long. He reminded the audience that there's three times as much groundwater as surface water, and that the two were once part of an integrated hydrologic system in which groundwater was recharged by infiltration of stream flow and rainfall and in turn supported extensive wetlands along the axis of the Central Valley, as well as sustaining Delta streams during dry months. The valley's aquifers constitute an enormous storage compartment for fresh water (102 million acre feet of usable storage or more than twice the amount stored in reservoirs statewide). Dubrovsky suggested it was time to analyze and confront the long-term costs of groundwater problems caused by overpumping and agricultural drainage - land subsidence and contamination - and to explore storage of water in aquifers rather than new reservoirs, thus re-establishing the hydraulic connection between water above and below ground.
Next on stage was Stanford's Steve Monosmith, who discussed the perils and the promise of using statistical models to predict how Estuary circulation and transport might respond to CALFED's efforts to restore the Delta. Monosmith advocated creation of a 21st century replacement for the Bay Model in Sausalito. This new three-dimensional Bay Model 2000 - to be housed in a network of desktop computers - would maintain accuracy by assimilating real time data from sensors throughout the system and could predict such things as phytoplankton dynamics resulting from creation of new shallow water areas in the Delta.
The creation of too much pavement in the Estuary watershed was Gary Binger's pet peeve. This speaker from the Association of Bay Area Governments described the challenges of getting 101 governments to reduce the amount of impervious surface causing urban runoff pollution, and to protect watersheds and stream corridors. Binger gave the Bay Area an environmental land use report card grade of "C-" - arguing that cities need to do much more to halt land-and water-wasteful sprawl with urban growth boundaries, cluster new development, promote urban infill, increase transit-oriented development, and stop zoning for jobs without providing housing. The latter has led to longer commutes and more pavement, hence more pollution.
Pollution caused by restoration was the surprise of the next talk, as the U.S. Geological Survey's Sam Luoma reminded the audience that one good thing does not always lead to another. He warned that removing dams or restoring marshes in areas with known deposits of debris from 1800s hydraulic gold mining might worsen the Estuary's already pervasive methyl mercury pollution (the form of mercury most easily taken up in the food chain). Luoma also pointed out that the proposed construction of a new canal around the Delta to help solve California's water supply and environmental problems would exchange the Bay's current supply of Sacramento River water for lower-quality San Joaquin River water.
Another potential negative impact from restoration is the increase of opportunities for exotic species to settle in. Disrupted soil, temporarily stripped of shading material, is ideal turf for invading riparian plants like Arundo donax (a habitat-and water-guzzling species commonly known as the "plant from hell"); likewise, salt ponds recently opened to the tides and newly created wetlands offer a blank slate for Atlantic cordgrass - a fast-spreading wetland plant currently making a folly out of many well-intentioned restoration efforts. According to U.C. Berkeley's Tom Dudley, the "build it and they will come" mentality must be tempered with planning to prevent unwanted vegetation. He also pointed out that the "stable hydrology" of the current highly controlled water system reduces biodiversity and promotes invasions.
One of the strongholds of native biodiversity, at least in terms of fish, are Bay creeks, said speaker Rob Leidy of U.S. EPA. Compared to Central Valley creeks, Bay creeks have more diverse and healthy assemblages of native fish. Indeed native species dominated 75% of sites sampled by Leidy in 30 watersheds. Reasons for good native fish survival around the Bay may include fewer dams, diversions and reservoirs (major sources of exotics), less distance to the open ocean for migrating anadromous species, and the salt water at creek mouths -preventing movement of freshwater species and invaders between drainages. "These are all strong arguments for focusing restoration on Bay streams," said Leidy, who has developed a list of high priority watersheds for restoration.
Restoration aimed at getting the most endangered fish, animals and plants back on their gills, feet and roots pervaded an information-packed panel on Day 2 of the conference. First up were fish. According to U.C .Davis' Peter Moyle, who reviewed the status of several declining native species, Delta smelt show no sign of recovery and nobody understands what's going on with green sturgeon. Numbers of splittail, salmon, longfin smelt and two other native fishes of concern have grown in last five years as a result of an unusual series of wet years and the accompanying increased river flows. A return of the drought and high rates of diversion will likely cause their numbers to plummet again, however. "Nature has cooperated ever since the Bay-Delta Accord, and bought us some time. We need to make some serious commitments to conservation before the next drought," said Moyle. To help the fish, Moyle called for more and better floodplains, more natural hydrological regimes, improved access to upstream habitats, and prevention of further invasions by exotic species.
Prevention won't do much for natives of the Estuary's muddy and rocky bottom, however. According to Cal Fish & Game's Kathy Hieb, up to 90% of the benthic community is comprised of exotic species in many places, and no amount of habitat restoration can bring back the natives. Hieb's talk explored the status of various invertebrate species, not just bottom-dwellers. In recent years, native zooplankton continued their decline dating back to the 1980s, she said, but Bay shrimp are on the rebound in part due to increased flows that aid shrimp migration and enhance nursery habitat. The ups and downs were nothing new to Hieb, who completed her talk by throwing up her hands and saying "There's no doubt that variability is the essence of the Estuary."
Owls and frogs could use a little more of that variability said the next speaker, at least in terms of habitats. Three quarters of the uplands once adjacent to the Bayshore have been farmed, grazed, logged, developed or otherwise destroyed, said San Jose State's Lynne Trulio, and today's levees now create a "hard edge around many wetlands, leaving virtually no transition to remaining uplands." Trulio zeroed in on the importance of this transition zone for the many birds, amphibians and terrestrial species (85% of special status species) that cross back and forth over the wetland/ upland edge in search of food and refuge. She said restoration projects are only just beginning to attempt to re-establish this essential habitat connection, listing Hamilton, Montezuma and Ora Loma as projects with planned or constructed interface zones. "The hydrological situation on these transitional habitats is very complex and difficult to replicate. The problem is, we have almost no moist grassland, no vernal pools left to copy," she said.
The hard edge of many wetland restoration sites doesn't do much for floristic diversity either, according to speaker Brenda Grewell of U.C. Davis. As slide after slide of rare petals and foliage graced the screen, Grewell reminded the audience that plants offer both ecological and aesthetic benefits. Habitat degradation and fragmentation, and intruding exotic flora, have diminished many emergent marsh plant communities, and decimated species such as soft-haired birds beak, Suisun thistle and Mason's lilaeopsis.
"Rare plants are our best barometers of Bay health, we know of some stands have been around since the 1800s," said Grewell. Unlike terrestrial species or fish, plants faced with poor habitat can't just move on to more suitable turf. Suitable for some means a complex combination of soil types, salinity changes and flooding regimes. According to Grewell, restoration opportunities that "link tidal marshes to alluvial soils, seeps and drainages should be a high priority. The current tendency to create tidal marshes as indented pockets within levee systems, separated from the historic margins of the Estuary, will not support historic floristic diversity."
Grewell warned that restoration planners should not assume that remaining marshes are good references of historic conditions-as many important plant species are extinct within these areas. Nor should they assume that the species studied most deserve the most effort-citing the greatest current limit on successful plant restoration as a lack of applied research. "Plants shouldn't have to grow gills to get our attention," she said.
Feathers do get more attention. Birders and scientists regularly aiming their binoculars at the skies and shores of the Bay count hundreds of thousands of waterbirds during their migration down the Pacific Flyway. With over 50% of their historic migratory habitat in the Western United States erased due to human development and agriculture, San Francisco Bay has become a critical stopover. "One can only wonder how birds and wildlife must have scrambled in the face of the disappearance of so much habitat," said speaker Gary Page of the Point Reyes Bird Observatory. Many species adapted to new habitats, such as the shallows and flats of the Bay's salt production ponds. Species favoring the new habitat include ruddy ducks, avocets, stilts, plovers and phalaropes. Page said that although tidal marsh and mudflat restoration in the Bay will help many birds, converting salt ponds to this end may not. "We can't turn back the clock for the Bay. Conversion of man-made salt ponds will have negative consequences for many waterbirds, birds that have no place else to go," said Page.
Far upstream where the wide shallows of salt ponds and Bay waters narrow into nine rivers and myriad tributaries, restoration efforts are often short-lived, said speaker Scott McBain of McBain and Trush. Here high flows are quick to damage or destroy the kind of patchwork attempts to restore individual gravel beds or river banks that have occurred without attention to the system as a whole. To better guide restoration, McBain listed ten attributes of a healthy, alluvial, low-gradient, gravel-bed rivers in the Central Valley, among them variable stream flows; frequent movement of riffles and bars by moderate floods; periodic channel migration; access to a functional floodplain; and sediment transport at approximately the same rate as delivered by the watershed. These simple, quantifiable attributes evoke the historic fluvial processes that underpin the river system, according to McBain. Based on these attributes, McBain's recommendations for river rehabilitation ranged from creating more varied stream flows and establishing continuous riparian floodways to increasing coarse and reducing fine sediment supplies and storage.
With the information and recommendations flying fast and loose for 13-hours straight, it's a wonder conference attendees didn't drift off to sleep in the deep red chairs and dark of the auditorium. Some may have succumbed by mid-afternoon on Day 2, but they sat up straight to hear well-known Joy Zedler from the University of Wisconsin.
Zedler and several other speakers described the critical follow-up task of monitoring the results of restoration efforts. Zedler's case in point was a 300-acre San Diego mitigation project called Sweetwater Marsh. In her evaluation of project success, Zedler looked at the degree to which compliance criteria had been met for three endangered species damaged by the development. Using remote sensing and satellite imagery as tools, Zedler examined habitat development over time and found that criteria for two species-the California least tern and salt marsh birds-beak-had been met. Habitat for the light-footed clapper rail, however, had serious short-comings, namely coarse soil, low nutrient supplies, short vegetation, scale insect outbreaks and inadequate nesting habitat. "Clapper rails never came to the site designed for them," said Zedler, "The cordgrass was too short to build nest canopies. The science eventually showed that all the problems were related to the soil, and that nitrogen wouldn't match desired levels for at least 40 years. In other words, the site would never achieve what was envisioned for it."
According to Zedler, lessons learned from the San Diego project pinpoint five ecosystem components that should not be ignored in restoration: anthropod predators (there were no beetles to prey on the scale insects); plant canopy structure; soil structure; soil nutrients and site-landscape interactions.
Another follow-up effort was described by Charles Simenstad from the University of Washington, who compared several different restoration projects of different ages in the Pacific Northwest to local control sites. Looking for a possible correlation between project age and fish utilization, he found that the numbers of juvenile Pacific salmon and a resident sculpin generally increased in the older marshes. Surveys of insects and benthic invertebrates also suggested that available prey and consumption became more diverse as marshes matured. "Now we need to look at the role channel complexity may have played in these findings," he said. Simenstad felt that although the promise of restoring tidal marsh ecosystems has increased over the years, efforts still suffer from the following pitfalls: "functional forcing" (restoring only one or two functions or habitats rather than a whole multi-functional ecosystem); "demand for instant gratification," (expecting marshes to mature in far less time than natural processes allow, and intervening to make things speed up, which is often counterproductive); and "maladaptive monitoring" (monitoring response without exploring the underlying ecological processes at work in the system.
As the conference progressed, speakers touched on myriad other topics ranging from restoring Delta islands, managing stormwater and working with wildlife-refuge neighbors to developing publicly palatable indicators of restoration success and coming to scientific consensus on ecosystem goals. Though managers and politicians followed the scientists onto the podium, their comments fell more into the category of speechifying than responding to the challenges outlined in prior presentations.
Clearly the pipeline between science and action isn't as direct as it needs to be to shift from mending the ecosystem's cuts and bruises to really relieving the immense pressure of our American way of life - what the conference's opening speaker Luna Leopold called "the national pursuit of unlimited growth"-on the salmon, smelt, sandpipers, stilts, thistles, willows and waters of the Estuary.
In the end, all the science in the world is nothing unless restoration generates the necessary social and political energy to make use of it. As engineer Jeff Haltiner of Philip Williams & Associates put it in the waning hours of of the conference: "It's nice to be involved in the restoration movement, it's kind of messianic, religious... When it gets boring and mundane, that will be when it's successful, because it will be ingrained in the culture of the country."
Contact: (415)989-2441 to get speaker phone numbers. A State of the Estuary Report summarizing conference proceedings will be published in late summer.
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