Wednesday, June 19, 2013

Suisun Thistle

2009-04 “Natural Community and Species Accounts”
Administrative Draft Solano HCP produced by “LSA Associates, Inc.” for Solano County Water Agency []:
SUISUN THISTLE (Cirsium hydrophilum var. hydrophilum)
USFWS: Endangered
CDFG: None
CNPS: List 1B
Species Account
Status and Description.
Suisun thistle (Cirsium hydrophilum var. hydrophilum) was federally-listed  as endangered November 20, 1997 (62 FR 61916) and is on CNPS’ List 1B. Three locations in  Solano County were designated as Critical habitat on April 12,  2007 (Federal Register Volume 72, Number 70). 
 Suisun thistle is a biennial or short-lived perennial herb in the  thistle tribe (Cardueae) of the sunflower family (Asteraceae).  This thistle has 1 to 2 m tall, erect stems that are branched above.  The margins of the leaf-blades and leaf-stems are spiny and both  leaf surfaces are thinly, cob-webby hairy. The flowerheads of  rose-purple flowers are 2 to 3 cm long and born singly or in small  clusters on the stems. The phyllaries (bracts below the  flowerheads) are spine-fringed with narrow, sticky-glandular  areas (Hickman 1993, USFWS 2003).
Range and Distribution. Suisun thistle is endemic to Solano  County, occurring only in Suisun Marsh. In 1975, this species  was reported as possibly extinct due to hybridization with bull  thistle (Cirsium vulgare) (California Department of Water  Resources 1994), because it had not been collected for about 15  years (USFWS 2003). It was rediscovered in 1989 by N. Havlik. Three  populations of this thistle are reported from Suisun Marsh: one at Grizzly Island Wildlife Refuge, one  at Peytonia Slough Ecological Reserve (CDFG lands), and one at Rush Ranch (Solano County Open  Space Foundation)(CNDDB 2008, CNPS 2008). All three sites are designated as Critical Habitat.
Habitat and Ecology. Suisun thistle grows in the upper reaches of tidal marshes, most often near  small watercourses such as sloughs or ditches dug for mosquito abatement. At Rush Ranch, it is most  commonly found growing with bullrushes (Scirpus spp.) and saltgrass (Distichlis spicata). Other  associated plants include alkali heath (Frankenia salina), pickleweed (Salicornia virginica), broadleaved  pepper-weed (Lepidium latifolium), and rushes (Juncus spp). At Peytonia Slough Ecological  Reserve, Suisun thistle was observed growing in peaty soil with cinquefoil (Potentilla sp.), water  parsley (Oenanthe sarmentosa), triglochin (Triglochin sp.), and rushes. It has been observed growing  with another endangered species, soft bird’s-beak (Cordylanthus mollis ssp. mollis). Suisun thistle  blooms July through September (CNPS 2008).
Suisun thistle appears to be more abundant in years with lower water levels or higher salinities when  competing species are less abundant (CDWR 1996). Annual observations of the Rush Ranch  population began in 1991 and has revealed a significant decline in the number of Suisun thistle plants  with some recovery in 1996. The Peytonia Slough population declined significantly in 1995 and 1996 while competing species increased. Considering the fact that this thistle grows along bare  sections of watercourses and appears to colonize disturbed areas (CNDDB 2008), Suisun thistle may  be a poor competitor and may require bare soil for seedling establishment.
Population Levels and Occurrence in the Plan Area. Three populations of Suisun thistle are  known from Suisun Marsh (see above). Population sizes reported for Suisun thistle on Grizzly Island  range from “five plants” to “three colonies” to “thousands of plants” (CNDDB 2008). More detailed  studies at Rush Ranch in 2003 estimated the Suisun thistle population there to be approximately  137,500 (22,300 – 873,200) that were lumped into 47 subpopulations (L.C. Lee Associates 2003), far  more plants than few thousand plants that were previously estimated by the USFWS (2003). The  long-term effects of a recent burn at Peytonia Slough Ecological Reserve on this thistle is not known.
Threats to the Species. In the past, marshland habitat was lost through development, dredge  disposal, diking, and agricultural conversion. Currently, changes in hydrology, invasive plant species,  including peppergrass (Lepidium latifolium), erosion, and feral pigs pose the greatest threats to Suisun  thistle (CNPS 2008; L.C. Lee Associates 2003). Indirect effects from urban development, mosquito  abatement activities, potential hybridization with non-native thistles, water pollution, and the  alteration of tidal regimes threaten the Suisun thistle (USFWS 2003). Furthermore, its highly  restricted distribution increases its susceptibility to random catastrophic evens such as disease or pest  outbreak, severe drought, oil spills, or other natural or human-caused disasters (USFWS 2003).  Populations are partly protected on the CDFG Grizzly Island Wildlife Refuge and Peytonia Slough  Ecological Reserve [CNDDB 2008, CNPS 2008]).
Literature Cited
 * California Department of Fish and Game (CDFG). 2008. California Natural Diversity Data Base (CNDDB). Sacramento, California.
 * California Department of Water Resource (CDWR). 1994. Summary of sensitive plant and wildlife resources in Suisun Marsh during water years 1984-1994. Environmental Services Office.
 * California Department of Water Resource (CDWR). 1996. Brackish Marsh. Vegetation
Subcommittee Report. Interagency Ecological Program, Suisun Ecological Workshop.
 * California Native Plant Society (CNPS). 2008. Electronic Inventory of Rare and Endangered Plants of California. Sacramento, California.
 * L.C. Lee Associates. 2003. Geographic Distribution and Population Parameters of the Endangered Suisun Thistle (Cirsium hydrophilum var. hydrophilum) at Rush Ranch In Solano County, California. Final Report. Prepared for the Solano County Water Agency.
 * Hickman, J.C. Ed. 1993. The Jepson Manual: Higher Plants of California. University of California Press. Berkeley, California.
 * U. S. Fish and Wildlife Service (USFWS). 2003. Suisun Thistle (Cirsium hydrophilum var.
hydrophilum). accts/suisun_thistle
2008-06-05 “Final Critical Habitat for Suisun Thistle and Soft Bird’s Beak”
map posted at []:

“Map 2. Critical Habitat Units 1, 2, and 3 for Suisun Thistle”
posted at []:

2007-04-15 “Designation of critical habitat for Suisun thistle and soft bird's-beak” 
 Fish and Wildlife Service
 50 CFR Part 17
 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Cirsium hydrophilum var. hydrophilum (Suisun thistle) and Cordylanthus mollis ssp. mollis (soft bird's-beak)
 AGENCY: Fish and Wildlife Service, Interior.
 ACTION: Final rule.
 SUMMARY: We, the U.S. Fish and Wildlife Service (the Service), are designating critical habitat for Cirsium hydrophilum var. hydrophilum (Suisun thistle) and Cordylanthus mollis ssp. mollis (soft bird's-beak) under the Endangered Species Act of 1973, as amended (Act). In total, approximately 2,052 acres (ac) (830 hectares (ha)) fall within the boundaries of the critical habitat designation for C. hydrophilum var. hydrophilum in Solano County, California, and approximately 2,276 ac (921 ha) for C. mollis ssp. mollis in Contra Costa, Napa, and Solano Counties, California. Due to overlap of some units, the total area of critical habitat designation for both subspecies is 2,621 ac (1,061 ha).
 DATES: This rule becomes effective on May 14, 2007.
 FOR FURTHER INFORMATION CONTACT: Field Supervisor, Sacramento Fish and Wildlife Office, 2800 Cottage Way, Sacramento, California 95825; telephone, 916-414-6600; facsimile, 916-414-6713. People who use a telecommunications device for the deaf (TDD) may call the Federal Information Relay Service (FIRS) at 800-877-8339.

2007-04-13 “U.S. widens habitat for two plants”
by Danny Bernardini from “Vacaville Reporter” newspaper []:
 In an attempt to further preserve two endangered wetland plants, the U.S. Fish and Wildlife Service has designated 2,621 acres of marshland in Solano, Contra Costa and Napa counties as critical habitat.
 The final ruling, published Thursday under the Endangered Species Act, will protect the Suisun Thistle and the soft bird's-beak. The two plants are found only in the tidal wetlands of the Suisun and San Pablo bays.
 Critical habitat is an area containing features essential for the conservation of a threatened or endangered species that may require special management considerations or protection.
 Most of the designated land, 2,215 acres, sits in Solano County, with 384 acres in Napa County and 22 acres in Contra Costa County. The designation includes 2,052 acres of critical habitat in Solano County for the Suisun thistle and 2,276 acres for the soft bird's-beak in Contra Costa, Napa, and Solano Counties.
 Among the critical habitat for the two endangered species, there is an overlap regarding the number of acres designated. That overlap, approximately 1,706 acres, is in Solano County in the Hill Slough and Rush Ranch units in the northern portion of the Suisun Marsh
 Most of the wetlands are owned by the state, public agencies and the Solano Land Trust. Only 309 acres are privately owned. Because this land is already protected there will be little change, according to Al Donner, assistant field supervisor for the U.S. Fish and Wildlife Service.
 Donner said the designation won't greatly affect how the area is managed, but rather bring attention to the plants and the areas.
 "It's like raising a billboard about the plant," he said. "It just makes people a little more aware of the tidal marshes."
 Critical habitat is an area containing features essential for the conservation of a threatened or endangered species that may require special management considerations or protection.
 Ben Wallace, conservation project manager with the Solano Land Trust, said the area already protects the two plants and would take any appropriate steps to do so further if prompted to by the fish and wildlife service.
 "We've always been careful with the use of the marsh," Wallace said. "We try and work proactively. If we have any questions, we would call them."
 One of the main adversaries of the plants are the feral pigs that inhabit the area. He said licensed hunters are brought in to combat the problem, but they continue to be a nuisance.
 "There's only so much we can do. Pigs go where they want," Wallace said.
2006-04-11 “Critical habitat suggested for 2 Bay Area tidal plants; Public review period open for 60 days”
from U.S. Fish and Wildlife Service []:
 The U.S.F.W.S. published today a suggested rule to designate approximately 2,726 acres of critical habitat in Solano, Contra Costa and Napa counties, California for 2 federally endangered plants, the Suisun thistle and the soft bird's-beak, found only in the tidal wetlands of Suisun and San Pablo bays.
 The Service is proposing to designate 2,119 acres of critical habitat under the Endangered Species Act (ESA) in Solano Co. for the Suisun thistle and 2,313 acres for the soft bird's-beak in Contra Costa, Napa, and Solano Counties. Some 1,706 acres overlap between the 2 plants as suggested critical habitat.
 Most of the critical habitat occurs on lands owned by the State, public agencies or preservation land trusts. About 327 acres are privately owned. Remaining populations of the plants occur in higher tidal marshes with small channels -- that is, higher marsh areas that drain into tidal sloughs.
 Public comments on the suggested rule will be accepted for 60 days. Comments may be directed by email to:, or by mail to: Field Supervisor, Sacramento Fish and Wildlife Office, 2800 Cottage Way, Room W-2605, Sacramento, California 95825.
 The Service is exempting the Concord Naval Weapons Station from the critical-habitat designation because it has adopted a resource-management project providing for conservation of the species. The station has approximately 402 acres of habitat for the Suisun thistle.
 The Service is also seeking public review on whether to exclude Suisun Marsh from critical habitat, on the basis that the pending Suisun Marsh Habitat Management, Preservation, and Restoration Project provides a better alternative for conservation of the species. The Project is being developed by the Suisun Marsh Charter Group (Charter Group), a collaborative effort among Federal, state and local agencies with primary responsibility for actions in Suisun Marsh. Among the group principals are the Service, U.S. Bureau of Reclamation, California Department of Fish and Game, California Department of Water Resources, Suisun Resource Conservation District, California Bay-Delta Authority, and National Oceanic and Atmospheric Administration's Countrywide Marine Fisheries Service.
 Critical habitat is a term in the ESA. It identifies geographic areas containing features essential for the conservation of a threatened or endangered species and may require special management considerations or protection. Federal agencies that undertake, fund or permit activities that may affect critical habitat are required to consult with the U.S.F.W.S. to ensure such actions do not adversely modify or destroy designated critical habitat. The designation does not affect purely private or state actions on private or state lands, nor require non-Federal lands to be positively managed for conservation.
 The Service listed the 2 plants, Suisun thistle and soft bird's-beak, as endangered in November 1997 but did not designate critical habitat. In November 2003, several organizations filed a lawsuit in the Northern District of California challenging the decision not to designate critical habitat. On June 14, 2004, the court approved a settlement in which the Service agreed to propose critical habitat for the 2 plants by April 2006 and complete a final critical habitat rule by April 2007. Today's action, published in the Federal Register, responds to that agreement.
 Suisun thistle is a perennial herb in the aster family, while soft bird's-beak is an yearly herb in the snapdragon family. Both species are threatened by the loss, fragmentation and degradation of tidal marsh habitat in the San Francisco Bay Estuary.
 In 30 years of implementing the ESA, the Service has found that designation of critical habitat provides little additional protection for most listed species, while preventing the agency from using scarce conservation resources for activities with greater conservation benefits.
 In almost all cases, recovery of listed species will come through voluntary cooperative partnership, not regulatory measures such as critical habitat. Habitat is also protected through cooperative measures under the ESA, including Habitat Conservation Plans, Safe Harbor Agreements, Candidate Conservation Agreements, and state programs. In addition, voluntary partnership programs such as the Service's Private Stewardship Grants and the Partners for Fish and Wildlife plan also restore habitat. Habitat for listed species is provided on many of the Service's National Wildlife Refuges and state wildlife management areas.
 A copy of the suggested rule and other information about the Suisun thistle and soft bird's-beak is accessible on the Internet at, or by contacting Sacramento Fish and Wildlife Office, 2800 Cottage Way, Room W-2605, Sacramento, California 95825 at 916-414-6600.
 The Service is preparing a outline economic analysis of the suggested critical habitat that will be released for public review and review at a later date.
 The U.S.F.W.S. is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 95-million-acre National Wildlife Refuge System, which encompasses 545 National wildlife refuges, thousands of small wetlands and other special management areas. It also operates 69 Countrywide fish hatcheries, 64 Fish and Wildlife Management offices and 81 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American tribal governments with their conservation efforts. It also oversees the Federal Assistance program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.
2006-04-12 “Habitat Protection Proposed for Two Bay Salt Marsh Plants”
from “Center for Biological Diversity” & “California Native Plant Society” []:

San Francisco, Calif.—In response to a lawsuit filed by the Center for Biological Diversity and California Native Plant Society, the U.S. Fish and Wildlife Service yesterday issued a proposal to designate and protect critical habitat in San Pablo and Suisun Bays for two endangered plant species. Suisun Thistle (Cirsium hydrophilum var. hydrophilum) and Soft Bird's-beak (Cordylanthus mollis ssp. Mollis) were listed as endangered under the Endangered Species Act in 1997.
 "Yesterday's announcement is a victory for science, these plants, the Suisun Marsh and wetlands in general," said Carol Witham, former President of the California Native Plant Society. "This critical habitat designation will be a powerful addition to ongoing efforts to restore and conserve these special species and wetlands."
 Both plants are extremely rare. Between 70 and 80 percent of the tidal marsh habitat that once supported the plants has been destroyed. Suisun Thistle was once believed to be extinct in Suisun Bay. It was rediscovered in 1989 and is currently restricted to a few scattered sites in less disturbed areas of Suisun Marsh. Soft Bird's-beak has been lost from large portions of its original range, including tidal marshes along the Petaluma River, Napa River and San Joaquin-Sacramento River Delta. Migratory birds, recreationists and communities depend on these marshes for habitat, enjoyment and water quality maintenance.
 The Suisun Marsh Habitat Management, Preservation, and Restoration Plan is being developed to conserve and restore the area. The Plan has been in development since 2001, and a draft is currently expected to be released in fall 2006.
 "These species and the Marsh will benefit tremendously from this critical habitat designation," said Emily Roberson, director of the Center for Biological Diversity's Native Plant Conservation Campaign. "Although we look forward to the Marsh Plan, and we commend those who are working so hard to create it, we still have not even seen a formal draft. Such plans are often delayed by budget problems or political interference. There is no guarantee that the Plan will be completed expeditiously or funded adequately. Conversely, protection of designated critical habitat is mandatory under the Endangered Species Act. This is why critical habitat is one of our strongest tools to assure protection–and promote recovery–of plants, fish and wildlife."
 U.S. Fish and Wildlife Service data show that species with designated critical habitat are twice as likely to recover as those without habitat protection. Current legislative proposals would gut critical habitat provisions from the Endangered Species Act, and could undermine efforts to protect endangered species like the Soft Bird's-beak and Suisun Thistle if passed. The legislation, HR 3824, passed the House of Representatives in September 2005. Similar legislation is being considered in the Senate.
 "This legislation would completely derail the endangered species listing program, remove protections for endangered species habitat and cut federal scientific oversight of projects that threaten endangered species," said Peter Galvin, Conservation Director of the Center for Biological Diversity. "If this legislation becomes law, our ability to protect endangered species and our natural heritage will be largely lost."
 The name and case number of this lawsuit is: Center for Biological Diversity, et al. v. Gale Norton, Secretary of the Department of the Interior, et al., CV 03-5126-CW

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