The U. S. Fish and Wildlife Service (Service) is required by section 4(c)(2) of the Endangered Species Act (Act) to conduct a status review of each listed species at least once every 5 years. The purpose of a 5-year review is to evaluate whether or not the species? status has changed since it was listed (or since the most recent 5-year review). Based on the 5-year review, we recommend whether the species should be removed from the list of endangered and threatened species, be changed in status from endangered to threatened, or be changed in status from threatened to endangered. Our original listing of a species as endangered or threatened is based on the existence of threats attributable to one or more of the five threat factors described in section 4(a)(1) of the Act, and we must consider these same five factors in any subsequent consideration of reclassification or delisting of a species. In the 5-year review, we consider the best available scientific and commercial data on the species, and focus on new information available since the species was listed or last reviewed. If we recommend a change in listing status based on the results of the 5-year review, we must propose to do so through a separate rule-making process defined in the Act that includes public review and comment.
The specific goals of this study were focused in three areas: landscape genetics in the San Diego fairy shrimp B. sandiegonensis; hybridization between B. sandiegonensis and B. lindahli; and conservation, management and recovery of B. sandiegonensis
PROJECT OVERVIEW
Vernal pool habitat in southern California, and specifically southern San Diego County, has been
greatly diminished as a result of extensive development throughout the region. The value and
function of remaining vernal pool habitat continue to be degraded by development-related
disturbances such as trespassing, grazing, and invasion of nonnative species. As a result, the
sensitive species that are supported by vernal pool habitat are also at risk: San Diego fairy shrimp
(Branchinecta sandiegonensis), Riverside fairy shrimp (Streptocephalus woottoni), and Quino
checkerspot butterfly (Euphydryas editha quino; Quino), which are all federally endangered
species, as well as the federally and state listed San Diego button-celery (Eryngium aristulatum
var. parishii) and the federally threatened spreading navarretia (Navarretia fossalis). To halt the
decline and stabilize the vernal pools in San Diego County, and restore habitat function and
sensitive species populations, restoration and management actions are necessary.
The City of San Diego (City), in cooperation with other coordinating agencies such as the
County of San Diego (County), San Diego Association of Governments (SANDAG), U.S. Fish
and Wildlife Service (USFWS), California Department of Fish and Game (CDFG), and
California Energy Commission (CEC), obtained grant funding1 to protect, restore, and manage
portions of the remaining vernal pool habitat in southern San Diego County. AECOM (formerly
EDAW, Inc.) was retained by the City to conduct a comprehensive assessment of existing vernal
pool sites within the jurisdiction of the City and County, develop and prioritize recommendations
for restoration and management of those sites, and implement restoration and management of the
sites.
This report summarizes the results of implementation of the restoration and management
recommendation actions at five key vernal pool sites in the County, as shown in Figure 1 (Nobel
Drive, Goat Mesa, Otay Lakes, Proctor Valley, and Marron Valley). More detailed maps of each
site are provided in Figures 2 through 6. Chapters 2.0 through 6.0 of the report correspond to a
specific site. Within each of these chapters, a description of the restoration and management
actions undertaken at the site are included (i.e., dethatching, weeding, reseeding, recontouring of vernal pools, installation of artificial burrowing owl burrows, and/or access control). A summary
of the site condition foll
Current SDecies Status: This plan addresses six vernal pool species that are
listed as endangered and one that is proposed for threatened status: Eryngium
aristulatum var. parishii (San Diego button-celery), Orcuttia calfornica
(California Orcutt grass), Pogogyne abramsii (San Diego mesa mint), Pogogyne
nudiuscula (Otay mesa mint), Riverside fairy shrimp (Streptocephalus woottoni),
San Diego fairy shrimp (Branchinecta sandiegonensis), and Navarretiafossalis
(spreading navarretia).
Pogogyne abramsii was listed as endangered on September 28, 1978. Pogogyne
nudiuscula, Orcuttia ca1~fornica, Eryngium aristulatum var. parishii, and the
Riverside fairy shrimp were listed as endangered on August 3, 1993. The San
Diego fairy shrimp was listed as endangered on February 3, 1997. Navarretia
fossalis was proposed for listing as threatened on December 15, 1994.
Historically, San Diego, vernal pool habitat probably covered no more than 6
percent ofthe county, approximately 520 square kilometers (200 square miles).
Currently levels estimate a loss of vernal pool habitat in the San Diego County
around 95 to 97 percent because ofintensive cultivation and urbanization (Bauder
and McMillan 1998). Lack ofhistorical dataprecludes the same depth of analysis
for Los Angeles County, Riverside County, Orange County, or San Bernardino
Counties, but losses are considered nearly total (USFWS 1993). The current
distribution ofpools in northern Baja California, Mexico, probably comes much
closer to the historic condition (Bauder and McMillan 1998).
Habitat Requirements and Limiting Factors: Following winter rainstorms,
vernal pools form in depressions above an impervious soil layer or layers. Water
evaporates from these pools during the spring and early summer. Vegetation
communities associated with adjacent upland habitats that surround the vernal
pools in southern California are valley needlegrass grassland, annual grasslands,
coastal sage scrub, maritime succulent scrub, and chaparral.
iii
Prior to 1945, the primary threats to southern California vernal poois were
grazing. water impoundments, and conversion to agriculture. In recent years,
urbanization and construction of infrastructure have resulted in losses of habitat
estimated to be as high as 97 percent. Urbanization can directly impact pools
through elimination of the habitat by soil alteration, vegetation alteration,
alterations in hydrological regimes, and water quality. Where pools remain th
This framework management and monitoring plan provides guidance to maintain and enhance the conservation values of the Ramona Grasslands Open Space Preserve. The Preserve supports many unique biological resources, provides a suite of important environmental services for the region, and preserves a rich cultural and historic heritage.
The Ramona Grasslands Preserve functions as a core habitat area within a regional network of existing and anticipated conservation lands. The coastal sage scrub, chaparral, and oak woodlands of the surrounding landscape, together with the grasslands, riparian habitat, and vernal wetlands of the core area, constitute an exceptional concentration of regionally and globally significant resources. That significance is reflected by the near complete overlap of the Preserve area by federal Critical Habitat designations (San Diego fairy shrimp, arroyo toad, and California gnatcatcher).
The Ramona Grasslands host a unique assemblage of resources:
? The southernmost population of the endangered Stephens? kangaroo rat;
? Unique vernal wetlands that support endangered San Diego fairy shrimp and several rare plant species;
? Santa Maria Creek and associated habitats are important for neotropical migrant songbirds and the endangered arroyo toad; and
? A diverse raptor community, including the largest population of wintering ferruginous hawks in San Diego.
Oak savannah, riparian woodlands, alkali playas, native perennial grasslands, and rock outcrops contribute to the diversity and ecosystem functions within the grasslands. These resources are imminently threatened by the indirect impacts of urbanization and thus require science-informed monitoring and management to ensure their persistence.
The Ramona Grasslands comprise a significant portion of the Santa Maria Creek subbasin of the San Dieguito River watershed. The Santa Maria Creek, which drains the urbanizing community of Ramona, flows westward through the grasslands, then through Bandy Canyon to its confluence with Santa Ysabel Creek. Below the confluence, the San Dieguito River flows through San Pasqual Valley into Lake Hodges, a City of San Diego drinking water reservoir. The creek corridor serves as both a hydrological and habitat linkage for numerous species. It also provides essential ecosystem processes, such as natural filtration of anthropogenic contaminants that may impair downstream water quality.
The Ramona Grasslands Preserve functions as a core habitat area within a regional network of existing and anticipated conservation lands. The coastal sage scrub, chaparral, and oak woodlands of the surrounding landscape, together with the grasslands, riparian habitat, and vernal wetlands of the core area, constitute an exceptional concentration of regionally and globally significant resources. That significance is reflected by the near complete overlap of the Preserve area by federal Critical Habitat designations (San Diego fairy shrimp, arroyo toad, and California gnatcatcher).
The updated inventory provides current and expanded information regarding the location of vernal pool basins and rare, threatened, and endangered biota within the City of San Diego. The resulting data, which includes vernal pools on private and public lands, will be analyzed to determine the extent of vernal pool protection, as well as current preservation and management needs. This new information will serve as the basis for updating the City of San Diego Vernal Pool Management Plan (1996), which identifies and prioritizes management activities for vernal pools on land owned by the City of San Diego.
A genetic study based on mtDNA sequencing of B. sandiegonensis from across its range found two evolutionary significant units "ESUs" that should be strongly considered for unique conservation status. Pool complexes that are in undisturbed areas are often genetically unique. This project examined population genetic structure in the federally endangered fairy shrimp Branchinecta sandiegonensis in order to gain insight into contemporary and historical connectivity among pools and pool complexes, and make conservation recommendations.
Prior to this study, only allozymes had been used to study genetic structure in this species (Davies et al. 1997), and there are very few DNA-level population genetic studies for any fairy shrimp. Davies et al. (1997) found significant genetic differentiation among 10 pools for B. sandiegonensis using allozymes, and evidence for a ?temporal Wahlund effect? within pools. (The importance of overlapping generations created by the fairy shrimp cyst bank may be reflected in heterozygote deficiencies within each pond.) The goal of this study was to expand coverage to include the majority of the species range, including all pool complexes on City of San Diego property. The choice of mitochondrial DNA sequence variation over allozymes for this study reflects the higher degree of precision that can be obtained with mtDNA sequencing. Also, sequence-level variation permits a wider range of analyses that can be used to separate contemporary and historical processes such as allopatric isolation and gene flow.
A genetic study based on mtDNA sequencing of B. sandiegonensis from across its range
found two evolutionary significant units "ESUs" that should be strongly considered for unique
conservation status. Pool complexes that are in undisturbed areas are often genetically unique.
90-Day Report for the Wet-Season Presence/Absence Survey for Vernal Pool Brachiopods Conducted on the Shinohara Parcel within the San Diego National Wildlife Refuge (SDNWR), San Diego County, California
The City of San Diego (City) Vernal Pool Habitat Conservation Plan (VPHCP) is intended to
provide an effective framework to protect, enhance, and restore vernal pool resources in specific
areas of San Diego, while improving and streamlining the environmental permitting process for
impacts to threatened and endangered species associated with vernal pools. The City developed
this VPHCP to provide for the long-term conservation, management, and monitoring of these
species and avoid costly delays and uncertainty associated with a project-by-project approach
toward vernal pool conservation. Implementation of the VPHCP will preserve a network of vernal
pool habitat in a matrix of open space; protect the biodiversity of these unique wetlands; and define
a formal strategy for their long-term conservation, management, and monitoring.
The VPHCP is a conservation plan for vernal pools and seven threatened and endangered covered
species that do not have federal coverage under the City’s Multiple Species Conservation Program
(MSCP) Subarea Plan (SAP), including five plant and two crustacean species.
This report summarizes the results of the site assessment performed by EDAW, Inc., including a review of historical data, and identifies the most appropriate techniques for restoring and managing vernal pool habitat to increase sensitive species presence and hydrological function and value. The report includes five key chapters, as follows: Chapter 1.0 provides an introduction to the project and the project background; Chapter 2.0 details the vernal pool site assessment approach and summarizes the assessment results; Chapter 3.0 describes the approach to site restoration and management; Chapter 4.0 provides comprehensive restoration management recommendations for each site; and Chapter 5.0 provides the priority site recommendations based on existing grant funds, including an estimated schedule and cost for implementation.
Vernal pool habitat in southern California, and specifically southern San Diego County, has been
greatly diminished as a result of extensive development throughout the region. The value and
function of remaining vernal pool habitat continue to be degraded by development-related
disturbances such as trespassing, grazing, and invasion of nonnative species. As a result, the
sensitive species that are supported by vernal pool habitat are also at risk. To halt the
decline and stabilize the vernal pools in San Diego County, and restore habitat function and
sensitive species populations, restoration and management actions are necessary.
The City of San Diego (City), in cooperation with other coordinating agencies such as the
County of San Diego (County), San Diego Association of Governments (SANDAG), U.S. Fish
and Wildlife Service (USFWS), California Department of Fish and Game (CDFG), and
California Energy Commission (CEC), obtained grant funding
to protect, restore, and manage
portions of the remaining vernal pool habitat in southern San Diego County. AECOM (formerly
EDAW, Inc.) was retained by the City to conduct a comprehensive assessment of existing vernal
pool sites within the jurisdiction of the City and County, develop and prioritize recommendations
for restoration and management of those sites, and implement restoration and management of the
sites.
This report summarizes the results of implementation of the restoration and management
recommendation actions at five key vernal pool sites in the County.
