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Estuary Health Check
Eight hundred people lounged in the red seats of the Palace of Fine Arts auditorium in San Francisco this October to hear 48 experts present the newest research, the best maps, the latest technologies, and the hottest debates over the resources, health and restoration of the S.F. Bay-Delta Estuary.
First up at the podium was Richard Katz, a member of the State Water Resources Control Board, who hammered at the theme of good science leading to good policy. His homework for the audience was to stop just talking to each other in science speak and to get out and educate "newbies" in the state assembly about how this ecosystem we are trying to save provides drinking water to 20 million Californians and affects jobs and the economy. After the dose of political realism came a little history from author Malcolm Margolin, who commented on how impressive the knowledge level of environmentalists attending such conferences had become. "Thirty-five years ago carrying a picket sign and having a flimsy poetic idea was enough, but today's activists have extraordinary scientific, political, economic, and technological expertise," he said.
A coming of age also figured in the subsequent speech by the U.S. Geological Survey's Fred Nichols, who noted that progress made in such things as reducing the impacts of raw sewage and learning about the Estuary's natural processes has been accompanied by a recognition that "the objectives of any group or interest will not be achieved simply by voicing unyielding denials of the objectives of others." Nichols closed by mentioning a number of challenges for the future, among them predicting what would be the regional effects of local construction or restoration projects; judging how non-lethal contamination levels in the Estuary's invertebrates and fish affect the fish, wildlife, and humans who eat them; and overcoming the "reticence of our institutions to take a whole system approach."
Further talks on urban challenges followed, with Tom Schueler of Chesapeake Bay's Center for Watershed Protection reminding listeners that "the greatest threat to estuaries continues to be the conversion of natural spaces to car habitat." He said research shows a decline in sensitive species at about 30% impervious cover, a decline of food variety and abundance at about 15% and a rise in chronic coliform (fecal) contamination at less than 10%.
The water-energy connection was then made by Peter Gleick of the Pacific Institute - every acre foot of water we use costs about 2-3,000 kilowatts of power, he said. "The more water we save, the more energy we save," he said. Gleick debunked a number of popular "myths," among them that there are water and energy shortages. He attributed both these problems not to a lack of the resource, but to a shortage of "intelligent management." He added that there were no rolling black outs this summer not because, as the TV ads would have us believe, we've quickly built new power plants but because Californians practicing a minimal level of conservation managed to shave 10-14% off peak demand levels. "The regulators need to watch the generators," he cautioned.
Shaving demand might also help with the global warming problem, which the U.S. Geological Survey's Mike Dettinger described as just one part of the region's long history of climatic variability. As a result of warming, Dettinger predicted "fresher winters and saltier summers," for the Bay, and less than 25% of current snowpack levels in some areas by mid-century. "In the past 1000 years, there have been much drier centuries with 100 year droughts and extreme flood periods. These old trends, superimposed by global warming impacts, promise that major hydroclimatic changes threaten the Estuary in the near future," he said.
Another threat will be earthquakes, said Mary Lou Zoback, also of the Geological Survey. Zoback spoke of a 70% chance of a major earthquake shaking the region's bridges and levees before 2030, but more ominously of the likely return to the days before 1906 when the region experienced a magnitude six quake every four years. "The stress shadow of the 1906 quake created a docile environment in the Bay Area," she said. "Future quakes will be larger, closer together and more costly." In terms of the Estuary, they might not only wipe out some levees, but also release a lot of old contaminants buried in the soft Bay mud, she added.
After lunch, the Point Reyes Bird Observatory's Nils Warnock spoke about factors affecting bird life in the Bay today, among them habitat changes (conversion of salt ponds to tidal marsh), proposed airport runways, the spread of invasive cordgrass and contaminants. Some of the contaminants come from the birds' food - invertebrates, zooplankton and fish - whose status was surveyed by Cal Fish & Game's Kathy Heib. Heib said a long-term shift from a warm to a cool ocean climate has benefited some species, like Chinook salmon and English sole, but not others. A plant that is not benefiting anyone, however, is exotic Atlantic cordgrass and it's hybrids, which Peter Baye of U.S. Fish & Wildlife said continues to colonize Bay mudflats and reshape the shoreline. "If we forge ahead and do restoration without getting rid of invasive plants, we won't achieve a lot of our objectives for ecosystem recovery," he warned. As of 2001, a total of 237 invasive species (both flora and fauna) were well documented within the Estuary, added the S.F. Estuary Institute's Andy Cohen.
Getting down to ground level, hydrologist Phil Williams then discussed how our view of sediment as a nuisance - choking shipping channels and muddying swimming beaches - has changed over the last few decades. But declining sediment delivery to the Bay (only 5 million cubic yards per year now), along with sea level rise and the creation of large new sediment sinks (restoration of subsided Delta islands, for example) will all reduce the mud supply. "Managing mud will be as important as managing toxics and exotics in the future," he said. "Large-scale restoration will be constrained by the small sediment supply."
After Williams, Stanford's Steve Monismith gave an overview of how numerical models have helped us understand hydrodynamic processes and the S.F. Estuary Institute's Rainer Hoenicke described strides in reducing toxicity in the Bay. One pollutant reduction effort has been the negotiation of TMDLs, a regulatory tool that sets a regional goal for a total allowable maximum daily load of a contaminant. The Bay's new mercury TMDL "beats on all the sources," said the S.F. Bay Regional Board's Khalil Abu-Saba. But because five old mines account for about 90% of the mercury problem, he said, "We need more bulldozers and fewer Ph.D.s to work on this." Three more speakers wrapped up the day, with talk of pesticides, biomarker research, and attributes of a healthy ecosystem. And retired Army Corps debris boat captain Eric Carlson sent everyone home with first hand tales of railroad cars full of whiskey stuck in the Bay mud, sea lions on his deck, and a snake adrift on a clump of peat moss.
Day two of the conference opened with the theme of ecosystem restoration, which CALFED's lead scientist Sam Luoma said required three things to be successful: a sophisticated investment strategy; careful documentation of what works and what does not; and an institutional system that responds to the evaluation of effectiveness.
Three groups of speakers then addressed restoring Central Valley rivers, the Delta and the Bay. The Resource Agency's Tim Ramirez kicked off by examining how salmon have responded to river restoration strategies. Then U.C. Davis' Jeff Mount said "flood management is the single most useful tool of ecosystem restoration," but four hurdles had to be overcome to use it: a 150-year history of hard engineering approaches to river management; working within a system specifically designed to limit interchange between the channel and the floodplain; the often small and disconnected scale of restoration projects; and the need to embrace restoration as a social, not just biological and physical, science.
We also need to recognize, said Stanford's David Freyberg, that ecosystem restoration is "fundamentally a design process, and that design is a different activity than discovery," which is what most scientists perceive their work as being. The challenge then, he said, is to design for complexity, variability and long term change using tools - dams, channels, levees - designed to simplify the ecosystem. You can't rely on nature to do all the rest of the work either, said Denise Reed of the University of New Orleans, who went on to debunk other restoration "myths," including "build it and they will come." Reed said "We shouldn't expect the system to have enough sediment in it to build new land, because it's not what our rivers ever did before. We don't need to build new marshes as high as natural ones, but we do need to rebuild the substrate to the level where vegetation can take over."
Some of the substrate is so low that restoration via such processes as microbial decomposition is fast becoming the only option, according to the Department of Water Resources' Curt Schmutte, referring to his work on subsided Delta Islands. "The only other option is to let these holes get deeper and deeper," he said.
Further downstream, Bay restoration is now revolving around the Ecosystem Habitat Goals completed by scientists in 1999. Much work has been done in the North Bay, according to consultant Stuart Siegel, whose new inventory of North Bay restoration projects estimates 13,569 acres of tidal marsh has been or will be constructed in the near future - a big leg up on the Goals Project's recommendation of 28,000 acres of this sub-region for optimum ecosystem health. A healthy ecosystem comes not only from bay wetlands, but also from healthy creeks and watersheds, according to the next speaker, the S.F. Estuary Institute's Laurel Collins. Collins showed intriguing charts comparing levels of erosion, debris, sediment, vegetation and other factors along nine creeks draining into the Bay. Other speakers expanded on shoreline and watershed restoration efforts.
After lunch, the subject matter honed in on Suisun Bay - that pivotal zone of the Estuary that has one foot in the Delta and one foot in San Francisco Bay. A parade of speakers explored layer upon layer of Suisun science, from the impacts of long-term rises in spring salinity levels since the 1930s (a 5 ppt increase, according to speaker Noah Knowles) to changes in sedimentation rates from a historical depositional situation in which 3 million cubic meters (mcm) were being deposited in the Bay every year to more recent times when 1-2 mcm are eroding away annually, according to the Geological Survey's Bruce Jaffe.
Other changes include revisions to the circulation model for the Bay and Carquinez Strait, said the Survey's Jon Burau, who showed slides of where scientists now think the water goes, and how tides, currents and topography influence turbidity, food production and sediment movement. Indeed scientists now know the area of maximum turbidity is not necessarily where the salinity hits 2 practical salinity units (or "x2"), as until recently thought, but on the seaward side of sills such as as Garnet Sill adjacent to Grizzly Bay, according to presentation by the Survey's Dave Schoellhamer.
Two other scientists went on to explore the impact of the invasive Asian clam Potamocorbula on the Suisun Bay food web, and how contaminants affect the clams and the birds and fish that eat them. The Survey's Robin Stewart, for example, showed a chart indicating a big increase in selenium concentrations in top predators like Suisun Bay sturgeon, which feed on the clams, between 1986 and 1999 but no increase for striped bass which feed on other organisms. On the heels of all this science was a multi-agency management presentation describing the current acrimonious debate over how much of Suisun Marsh should be kept as heritage waterfowl habitat and hunting grounds and how much converted to much-needed tidal marsh.
Day three of the conference dawned with snapshots of key biological components of the ecosystem - fish, habitat and flows. U.C. Davis' Peter Moyle looked at the ever changing balance between native and alien fishes, but said both kinds of populations are in decline: "the peaks and valleys in their numbers are both getting lower" (see graph p.5). Habitat for the fish came next, with S.F. State's Wim Kimmerer discussing characteristics of the fish-friendly low salinity zone in the Estuary, and how it moves with changing flows (x2), and the U.S. Geological Survey's Larry Brown exploring the benefits of "shallow water habitat" (shoals, marshes, river flood plains) for fish. The recent push to create new shallow water habitat, and the use of this new habitat by alien species, has raised many questions about what kind of habitat is best to restore for natives. Brown says research on alien and native fish abundance in Suisun Marsh showed natives favored the small sloughs. "This helps us choose from the universe of shallow water habitat restoration options - we want the ones that look like small sloughs," he said.
Other speakers talked about Pacific herring and the benthic community, and Water Resources' Brad Cavallo closed with the proverbial big fish in the pond: salmon. He said we had to stop trying to manage them as "freeway fliers" speeding straight up and down the rivers, and start noticing that they're more like "Sunday drivers" stopping off here and there in side channels and often moving back and forth. "Fish don't follow the robotic life history we invent for them," he said. "So we can't just continue to focus on minimizing mortality at bottlenecks."
Near the end of the conference, two old hands in Estuary management provided some interesting perspectives. Steve Ritchie, formerly of the water quality board and CALFED, looked at our management track record and said that the S.F. Estuary Project's 1993 consensus-based plan for the Bay-Delta (see Feedback p.5) "changed the way we do our business, moving from legislative to more collaborative efforts like CALFED." But the eloquent words that rang in the ears of many leaving the conference were those of U.S. EPA retiree John Wise: "It's time to move science into the public domain, to communicate the beautiful chaos of the Bay-Delta system to those around us, and to re-engage the public in long-term programs to protect the Estuary."
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