1.1 MB pdf - Bolsa Chica Lowlands Restoration Project

SECTION 2:PROBLEM FORMULATION
2.2.1.2 Brackish Marsh
Areas of fluctuating or moderate salinity typically support both salt marsh and freshwater
species. Sedges (Carex spp.) and bulrushes (Scirpus spp.) are found in the brackish marshes
at the Lowlands. Brackish marshes, a small component of the Lowlands, are found in
scattered areas mostly along the perimeter of Inner Bolsa Bay as well as at the former gas
plant ponds/sumps and Freeman Creek.
2.2.1.3 Saltgrass
Dry, high saline sites are dominated by saltgrass often associated with pickleweed. Saltgrass
habitat is found near the former North Bolsa Tank Farm (NBTF) and Rabbit Island.
2.2.1.4 Tidal and Non-Tidal Open Water
Unvegetated areas of tidal water include the Inner Bolsa Bay, and unvegetated areas of
non-tidal water include channels and ponded water not created by tidal changes (mostly
on the east), such as the pond in Cell 38 and the unnamed drainage downgradient from the
golf course.
2.2.1.5 Tidal and Non-Tidal Mudflats
Tidal and non-tidal mudflats are unvegetated areas that have been covered by water for
long periods. Tidal mudflats are periodically exposed during low tide. Non-tidal mudflats
appear during summer and fall, when water levels recede and expose the bottoms of
seasonal ponds and edges of perennial ponds. Tidal mudflats provide higher quality
foraging habitat than do non-tidal mudflats.
2.2.1.6 Upland
Upland habitats at the Lowlands include areas of ruderal vegetation; coastal scrub habitat
dominated by coyote brush (Baccharis pilularis), California sagebrush (Artemesia californicus),
and saltbush (Atriplex sp.); and dunes and sandy flats that support sparse low herbaceous
vegetation species. Ruderal habitat is found along road berms, by oil pads, and adjacent to
buildings. Coastal scrub habitat is found along the bluffs of Bolsa Chica Mesa and on Rabbit
Island (Jones and Stokes, 1995).
2.2.2 Identification of Potential Ecological Receptors
The following sections summarize occurring animal species identified in the terrestrial and
aquatic habitats on the Lowlands. A detailed species list can be found in Table 2-1.
2.2.2.1 Species Observed or Expected to Occur
A list of species potentially found at the Lowlands was generated from the California
Wildlife Habitats Relationship Database System (WHR) (California Department of Fish and
Game [CDFG], 1998) (Table 2-1). This list was tailored to the Lowlands using professional
judgment and knowledge of the species. An information system created through multiagency
cooperation and maintained by CDFG, the WHR’s database components are used to
assess terrestrial vertebrate species occurrence, habitat requirements, life history information,
and relative abundance. Each species was cross-referenced with information collected during
site visits and reviews of published and unpublished data (CDFG, 1998; USACE, 1995) to
determine the accuracy of habitat associations, geographic distributions, and listing status.
ERA REPORT 2-6 SAC/143368(002.DOC)
7/31/02