California Sea-blite

Suaeda californica

Description

California sea-blite, Suaeda californica, is a succulent-leaved perennial plant of the goosefoot family (Chenopodiaceae). It was first described by Sereno Watson in 1874 based on a collection made in the salt marshes of San Francisco Bay. Amos Heller published the name Dondia californica in 1898, recognizing the genus name used by Michel Adanson in 1763; however, the name Suaeda has been conserved by the International Rules of Nomenclature. In 1959, taxa that had previously been recognized were reorganized as subspecies of S. californica. With this treatment, the range of S. californica was described as extending from San Francisco Bay south to Lower (Baja) California.

However, in 1983, scientists noted that much of what had been identified as S. californica in southern California and Baja California is a distinct taxon, which they named Suaeda esteroa. Although both species occur in the upper intertidal zone, S. californica is a shrub with radially symmetrical flowers belonging to the section Limbogermen, and S. esteroa is an herbaceous perennial with bilaterally symmetrical flowers belonging to the section Heterosperma. Further study revealed that the only extant populations of Suaeda that resemble the type specimen of S. californica are those that occur in the vicinity of Morro Bay. In a 1993 revision of the genus, S. californica was recognized as a full species.

Habitat

Suaeda californica occurs along the perimeter of Morro Bay, where it is restricted to the upper intertidal zone within coastal marsh habitat. The shrubs are discontinuously distributed in a narrow band around the Bay adjacent to other marsh plants including Salicornia sp. (pickleweed), Distichlis spicata (saltgrass), Juncus acutus (rush), Jaumea carnosa (Jaumea), and Frankenia salina (Frankenia) and the federally endangered Cordylanthus maritimus ssp. maritimus (salt marsh birds-beak).

Distribution

In 1992, the distribution of S. californica around Morro Bay was mapped. On the east side of the bay, colonies occur adjacent to the communities of Morro Bay, Baywood Park and Cuesta by-the-Sea, though it apparently is absent from the more interior portion of the marshlands that are created by Chorro Creek runoff. On the west side of the bay, S. californica is found along most of the length of the spit excepting the northern flank adjacent to the mouth of the bay. According to botanical consultant Dirk Walters, Elkhorn Slough in Monterey Bay is the only other remaining location considered to be potential habitat for S. californica on the California coast, but this area has not been recently surveyed. Suaeda californica 's colonial habit make it difficult to determine the total number of individuals comprising the species. One estimate places the number of individuals at no more than 500.

Threats

Suaeda californica is discontinuously distributed around the narrow upper intertidal zone of Morro Bay where it is concentrated in three stands. One stand is located on tidal flats within Morro Bay State Park. A second stand, consisting of only six plants, is located within Sweet Springs Marsh. The third population is located within Montana de Oro State Park. All three stands are threatened by recreational activity on the tidal flats and erosion from changing hydrologic conditions in the intertidal zone. Sedimentation of the Bay from the Los Osos Creek and Chorro Creek watersheds has altered the abundance and distribution of marsh habitat on the east side of the bay. Dredging of the Bay may alter sub-surface currents and affect shoreline stability. The California Department of Parks and Recreation is currently developing a proposal to dredge the marina at Morro Bay State Park; according to the U. S. Fish and Wildlife Service, this activity will likely result in the removal of a dozen individual plants. S. californica was collected from a fourth location just north of Morro Bay but has not been seen there since 1929. The type locality, on Alameda Island in San Francisco Bay, has long since been altered by urbanization as has much of coastal marsh habitat along the central California coast.

While Suaeda californica is a perennial plant, the low number of individuals and restricted range of the plant within the widely fluctuating hydrologic conditions in Morro Bay also subject it to stochastic extinction.

Conservation and Recovery

Two of the three known stands of the California sea-blite are located within state parks, where the habitat is not threatened by intensive development. However, these populations are threatened by recreational activity in their habitat, and by erosion from changing hydrologic conditions. The trampling by recreationists should be prevented by prohibiting this activity within the habitat of the rare plant. Proposals for dredging should not be allowed if critical habitat is threatened. The habitat of the third known population, in Sweet Springs Marsh, should be protected. This could be done by acquiring the land and establishing an ecological reserve, or by negotiating a conservation easement with the private landowner. The populations of the California sea-blite should be monitored at its known habitats, and searches made to see if there are any undiscovered populations. Research should be conducted into its biology and habitat needs. Additional populations should be established in suitable habitats.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

Ventura Fish and Wildlife Office
2493 Portola Road, Suite B
Ventura, California 93003-7726
Telephone: (805) 644-1766

Reference

U. S. Fish and Wildlife Service. 15 December 1994. "Endangered or Threatened Status for Five Plants and the Morro Shoulderband Snail From Western San Luis Obispo County, California." Federal Register 59 (240): 64613-64623.