Overview:
One of the most biologically rich areas of the world, California's natural wealth has evolved from a superabundant variety of terrain, micro climates, and soil types. Given the rapid, exponential growth in human numbers that has taken place in recent decades within this setting, state Fish and Game researchers say a major disruption of natural ecosystems has been likely. In fact, human activity has reduced some of California's most productive natural communities--its wetlands--by more than 80 and perhaps as much as 99%. And loss of wetlands is reflected in species counts: in 1993, California was home to more federally-listed threatened and endangered species than any other state in the continental US.
Sonoma County shares many of the same natural features attributed to the state as a whole: coastal zones, mountainous areas, wooded hills, rich alluvial fans and basins, floodplains, wetlands and streams. The county also shares in the state's predicament, with high human population growth rates impacting natural communities. Seventeen native species were in danger of extinction in the county in 1993, primarily as a result of human activity; another eight ranked as rare or threatened. Although the populations of a few locally extant species are stabilizing, in part thanks to human aid, the numbers of most continue to flounder. There remain formidable obstacles to large varieties of wildlife flourishing in Sonoma County--the most prominent among them being, as in the rest of the state, the rapid rate of land conversion.
The foremost cause for species endangerment in Sonoma County is the continued degradation, fragmentation, or reduction in size of wild and natural habitats. Some species have already become extinct locally for this reason, their numbers diminishing with the loss of coastal and interior marshes and seasonal pools; naturally configured streams, creeks, and patterns of drainage; mature forests and individual trees; thickets and trees near water (riparian vegetation); and places where unusual soil types and conditions are present.
These habitats often play an important role in the maintenance of our natural infrastructure. Wetlands, forests, and plants near water are our air and water purifiers, erosion controllers, and flood buffers, as well as places that shelter, feed, and regenerate wildlife. Human impacts on natural water-oriented communities are associated with 12 of the 25 species now listed in the
county as rare, threatened or endangered. Another seven listed species--two of them now absent from the county--have depended on trees or forests for survival. Eight species are at risk because they evolved under a unique set of conditions present in only one or two places.
Management:
Wild species are the concern of the state Department of Fish and Game and the federal Fish and Wildlife Service, while the management of their habitats falls under a broad array of jurisdictions, regulations, and individual concerns.
Biologists at the local level have long maintained that the principal means of protecting wildlife from land use impacts--the project-by-project review of development proposals at the local level, subject to state and federal scrutiny and intervention--has failed to work. Since the passage of the first state and federal species protection acts in the 1970s until recent years, government has relied upon this method to safeguard otherwise unprotected habitat. In 1991, state legislators initiated Natural Communities Conservation Planning, a pro-active approach focused on saving as much of a natural community supporting a species of concern as is possible, taking into account human needs and those of other species.
Recent efforts of this nature in Sonoma County have so far yielded mixed results. A plan to map and manage wetlands, vernal pools, natural wildlife corridors and waterways within the City of Santa Rosa's boundaries elicited a warning from the county's water agency that more streamway would have to be channelized if lowland development was to continue. Controversy over private land ownership rights has stalled county proposals to protect riparian corridors and vernal pools, weakened county Heritage Tree and tree preservation ordinances, and slowed protections for the Laguna de Santa Rosa. A Vernal Pool Task Force formed in 1989 succeeded in creating a voluntary Memoranda of Understanding among vernal pool preservation and development concerns in the central county corridor, but the Santa Rosa Plains Plant Protection Program, a more formal measure to manage the vernal pool ecosystem submitted to county planners in 1990, at the time of this report had not cleared review.
Assessment:
The human activities threatening listed species in the county vary, ranging from timber harvesting and land-clearing for fire protection or agriculture, to poisoning or shooting animals. Rural and urban development is the most oft-cited cause leading to endangered status, followed by livestock grazing or overgrazing, other forms of more intensive agriculture, and human disruption of wild places, including off-road vehicle (ORV) recreation. (For a chart of listed species and impacting activities, see Appendix A.)
By these and other means, the county has witnessed the extirpation of at least four species from within its borders in recent years: the marbled murrelet, willow flycatcher, California brackishwater snail, and Baker's larkspur. The marbled murrelet had occupied old-growth conifer forest along the coast from Monterey to Oregon before timber harvesting over the last 150 years reduced its range down to 3 to 10% of the original. The willow flycatcher, once common throughout the state, has, with the eradication of willow thickets, been reduced to about 200 pairs statewide. Sedimentation and other forms of water pollution drove the brackishwater snail from northern coastal marshlands, including those in Sonoma County; it was last reported seen in the Petaluma River marsh in 1964. Grazing, roadside maintenance, and farmland conversion cleared away all Sonoma County populations of the originally rare Baker's larkspur, leaving one population in Marin.
Three other species have suffered perhaps irreversible losses. A single individual remains to represent the Pitkin Marsh Indian paintbrush, reputedly still growing on private land outside Forestville. The last remaining population of Vine Hill manzanita grows sequestered in a nearby preserve. Many-flowered navarettia, an early casualty of land conversion in the Santa Rosa plains, persists in one known population.
Conservation and restoration efforts have stabilized populations of five other species: the Pitkin Marsh lily, Pennel's bird's beak, Baker's manzanita, bald eagle, and peregrine falcon.
A present-day listing as stable does not ensure the future of a species unless the threats to it can be resolved. In cases of pollution, grazing, ORV recreation and competition from introduced species, public education, restoration and enforcement actions may suffice. But because most listed species are refugees of land use change and the activities associated with it, they won't last long if preserved in isolation. Hence, the state predicts that the
number of listed species will continue to mount, and most of those listed will decline further still, as has occurred in Sonoma County, if preservation continues piecemeal.
The number of species within Sonoma County officially listed as nearing extinction rose from one in 1967 to 25 in 1994.
Locally, most of our listed species are in a state of continued decline despite current protections, while the total number of species at risk continues to rise. Four in the county were officially endangered in the early 1970s, the bald eagle among them; another 13 species had received protection by the decade's end, and five more joined government rosters in the 10 years that followed. With the advent of the '90s another three--the northern spotted owl, Clara Hunt's milk vetch, and Sonoma sunshine--have come aboard, while two state-listed vernal pool plants growing in Sonoma County rose to federal endangered status.
Sources:
State Department of Fish and Game, Natural Diversity Database; Sonoma County General Plan (Land Use Element); Press Democrat timeline survey; Santa Rosa general plan; county planners Sigrid Swedenborg, Jim Olmsted.
Special Reports:
The Laguna Technical Advisory Committee, in Fish and Wildlife Restoration of the Laguna de Santa Rosa (1989?), found that the central county's rapid shift from a resource-based to urban economy over the past 30 years has indirectly
ravaged the Laguna de Santa Rosa by forcing agriculture off the prime soil of the Santa Rosa Plains into the Laguna's more marginal wetlands. Farmers and ranchers have had to alter this new environment to suit their needs. As a result, "critical habitats ... have been filled and cleared to extend acreage and growing seasons and accommodate livestock," the committee found, "and, with flood control channels, accommodate development" (4).
The valley oak is being lost from the area's oak savannah as trees are cleared and older ones die. Root rot caused by summer wastewater irrigation appears to be a major cause.
The committee noted the Laguna's former status as an important salmon and steelhead nursery in the Russian River watershed, and as a major habitat for mallard and cinnamon teal. It is a popular stopping-place on the Pacific Flyway and remains one of the most significant coastal freshwater wetlands in the state, home to 3,000-5,000 waterfowl.
The committee proposed preservation and restoration of more than 7,000 acres of Laguna wetlands, less than one-eighth of the original acreage occupied by the Laguna earlier in the century.
Ronald Messer and Joe Brumbaugh, in Distribution and Status of the California Freshwater Shrimp (1989): This state- and federally-listed endangered shrimp was found in 10 streams in Napa, Sonoma, and Marin counties during the authors' study period. It was not found in historic habitat in the Laguna and Santa Rosa Creek. Researchers cited low water levels, brought about by drought and water diversion, as well as polluted runoff, intensive agricultural practices, and lack of shady stream cover, as the shrimp's nemeses. Its numbers are limited enough in some creeks that a single event could exterminate them.
Marco Waaland, in Baseline Evaluation (1989): Riparian forest in the Laguna de Santa Rosa has diminished by 73%, leaving 272 acres of the original 950. The riparian forest-dwelling western yellow-billed cuckoo and California freshwater shrimp were last observed there in the 1950s, before channelization eliminated much of their habitat. One of the valley oak's last local strongholds is the Laguna area, Waaland said, but haycropping and cattle grazing have prevented its regeneration there, and irrigation is suspect in the
excessive rate of root rot and death among mature members of the species. The valley oak has not reproduced naturally in the area for the last 80 to 100 years.
Peter Connors and John Maron, in Estero Americano Bird Population Study (1989): The partially polluted waters of the estero haven't deterred surprisingly large numbers of birds from flocking there. Researchers witnessed several thousand members of one species collecting at a time, following shifts in the tide. Hordes of western sandpipers, Dunlin and other birds representing more than 62 different species altogether continue to come to the estero for food. The estero is a designated breeding ground for ocean life in the Farallones National Marine Sanctuary.
Waaland and Joan Vilms, in Santa Rosa Plains Plant Protection Program Report (1990): Rare plants in vernal pools lacing the Laguna drainage from Cotati to Windsor are nearing extinction, Waaland's study found. Sonoma sunshine now exists in 30 known locations, or six biological populations; Burke's goldfields in 33 (5); and Sebastopol meadowfoam in 19 (6), most of these on land zoned for development within Santa Rosa's ultimate urban boundary. Vernal pool mint occurs in six locations (5 pop.) and many-flowered navarretia occurs on one known site. The species, showy Indian clover, specialized to the locale, was not found in this survey.
Vernal pool habitat had at one time covered more than 10,000 acres in the central county. At least 87% of the plant and animal communities native to the Laguna have been altogether eliminated by land grading, stream channelization, vineyards, orchards, imported grass species, and irrigation, Waaland said.
Populations of native species not yet warranting protective measures in the rest of the county or state may already qualify for threatened status within the Laguna, Waaland said. He estimated that one out of every six native species, such as the valley oak, is now locally rare or endangered, compared with one out of every eight statewide. Once a "mosaic" of vernal pools, oak savannah, riparian woodland and freshwater marsh, the Laguna is now scattered oases surrounded by artificial environments, its natural biotic linkages severed, according to Waaland. Roadway improvements and urban expansion threaten what remains.
Waaland said bleak prospects lie ahead for the rare species remaining in the Santa Rosa Plains in the absence of a comprehensive conservation program.
Charles Patterson, in Vernal Pool Creation (1990): Contrary to Waaland's findings, rare plants in the Santa Rosa plains' vernal pools exist in sufficient numbers to be saved, according to Patterson's study. Patterson found significant percentages and numbers of vernal pool species protected and not in imminent danger of extinction, although he said the purchase of natural sites for future preservation appears unlikely. A number of rare plants have grown successfully for several years in transplanted communities on artificially-created pool sites, according to Patterson.
David Smith, et al., in Laguna Characterization Study (1990): In a study area covering 28,000 acres, Smith's group made findings similar to those of Waaland's. The Laguna is the second largest freshwater wetland complex in northwestern California, yet less than one-quarter of its original marshlands remain. Landowners and mosquito abatement workers continue to drain and fill small portions, while parcels in agriculture are now undergoing rural and urban development: urban uses now cover 40 percent of the Laguna drainage basin. Of the 18,000 acres in its west-central agricultural area, more than one-quarter are under Williamson Act (agricultural) protection.
The report charts a rise in human population concurrent with the reduction of agricultural acreage between 1850-1990, and a decline in natural features alongside rising artificial uses.
The most insidious loss of diversity in the Laguna, according to the report, is the displacement of native species by "weed species" such as annual grasses, starlings, bullfrog, and carp, which have acted to genetically isolate native populations already disturbed by changes in land use. The burrowing owl, a state-listed species of special concern, with one population known to exist in the county, may already be gone from the Laguna, along with the red-legged frog, western rattlesnake, badger, bat, and ringtail.
The highest concentration of rare and endangered species in the county occurs here, and includes white sedge, Hoover's semaphore grass, bald eagle, and peregrine falcon.
Numbers of returning steelhead trout have been low in recent years in the Laguna, the report says. The authors cite water quality degradation, with high levels of ammonia and low amounts of dissolved oxygen, likely caused by urban and agricultural runoff.
Wildlife Center Reports: Operators of the four wildlife rescue and rehabilitation centers in the county each year submit intake tallies to the state Department of Fish and Game. Residents brought in 2,254 animals to the centers in 1989. Many of them had been picked up and separated from their kin unnecessarily, operators said, and a large proportion had been injured in car accidents or mauled by pets. Other causes of injury included trapping in residential areas abutting open space, loss of food, water, and cover to development, and fencing, poisoning, entanglement, and shooting.
"People want wildlife, but they don't want it near them," Sonoma Wildlife Rehabilitation Center director Barbara Elliott said in a telephone interview. "The biggest problems wildlife in Sonoma County faces are intolerance and loss of habitat."
John Berger, ed., in Ecological Restoration (1990): More than 20 individual sites in the county were the focus of restoration efforts reported between 1978 and 1990, including shrimp habitat in Huichica Creek in the east county, the Adobe Creek steelhead and striped bass fishery outside Petaluma (a highschool club project); Petaluma marsh, and San Antonio Creek at the site of a former drive-in theater. In addition, landowners and agencies teamed up to help restore five coastal watersheds in agricultural zones, four channelized creeks around Healdsburg, Windsor, and Santa Rosa, a marshland and two vernal pools. Volunteers and agencies helped transplant oak seedlings in Annandel State Park and the Laguna, and revitalized two wetlands in the Laguna, one of which now draws "vastly increased numbers of waterfowl, shorebirds, upland game birds, raccoons, river otters, fish, and deer" (166).
Ted Wooster, in "Memorandum on the Northern Spotted Owl" (1990): The endangered spotted owl appears to be "much more common than previously thought" (4) with more than 40 individual roosts or nests within the county in 1992, according to Fish and Game biologist Wooster, who provided the updated count in a telephone interview. Virtually all the roosts or nest occurred in
groups of trees at least 70 years old in second-growth forest on steep slopes, including one site on recently logged land in the newly-designated Willow Creek Park near Jenner.
Wooster's study disputes contentions that the Northern spotted owl depends on stands of forest at least 200 years old for its survival, and it more than doubles the number of spotted owls known to exist in the region since observations began in 1986.
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