Salt Marsh Bird's-beak

Cordylanthus maritimus ssp. maritimus

Description

Salt marsh bird's-beak, Cordylanthus maritimus ssp. maritimus, is an unusual component of the salt marsh ecosystem. This annual plant is hemiparasitic—deriving water and other nutrients through the roots of other plants. The plant is a branched annual with two distinct growth forms. In its northern range, it is large and profusely branched, flowering from May to October. Populations at Tijuana River estuary and southward are compact and scarcely branched. These southern populations flower as early as April and continue to bloom as late as December.

Leaves often are purplish, although some plants are predominantly light green. The bracts are finely haired. Northern plants have flowers with conspicuous, purple, three-lobed floral bracts, while southern plants have pale cream flowers with faint purple lines. Flower color also varies within marshes having many isolated colonies.

Habitat

Salt marsh bird's-beak occurs in tidal wetlands throughout its range. Populations are generally found in areas of lower salinity and light vegetative cover. Plants grow in the middle littoral zone, which is above the zone where vegetation is bathed by the twice-daily high tide, but below the upper littoral zone, where the ground is covered by water only during very high storm tides. Salt marsh bird's-beak is found in association with pickleweed, salt-cedar, salt grass, alkali heath, and sea lavender.

Colonies infrequently grow behind barrier dunes, on dunes, or on old oyster shell dredge spoils. Most sites are well-drained and well-aerated soils, drying out during the summer. The major marshes of southern California typically harbor the species. This plant is also found in freshwater seeps at Point Mugu.

Populations show large fluctuations from year to year, perhaps the result of variations in annual seed production or in the number of seeds reaching suitable germination sites. Because of development and the draining of wetlands, many extant populations are widely separated, limiting gene exchange.

Distribution

Salt marsh bird's-beak once grew in tidal wet-lands all along the coast from southern California to northern Baja California in Mexico. Records show that plants occurred in 18 sites, three of which were inland marshes whose precise locations have been lost.

Since 1975, salt marsh bird's-beak has been verified from six general areas, and has been reported from a new site, Ormond Beach, near Point Mugu, California. Colonies in Baja California, Mexico, are known only from the San Quintin-Laguna-Mormona marshes, more than 120 mi (200 km) south of localities at Tijuana River Estuary.

Total estimated population counts for salt marsh bird's beak have not been made from all sites, but several were surveyed in 1988. One site along Upper Newport Bay was estimated at a maximum density of 172 plants per sq m (1 sq m=1.2 sq yd). A population in Sweetwater Marsh near San Diego was estimated between 100 and 150 plants in 1981. At Tijuana Estuary storms and flooding in 1987 reduced the population by half, to an estimated 1,788 individuals.

Threats

Coastal salt marshes are subject to constant change, such as erosion and deposition of sediments, migration of stream channels, flooding, and varying soil salinity. Shifting of sandy barriers at the mouths of estuaries periodically closes off specific marshes to tidal action, creating unfavorable habitat for bird's-beak. If freshwater flows into salt marsh areas are increased, without an increase in tidal inundation, the salinity of the habitat is changed, transforming the area into a freshwater marsh supporting a different plant community.

All sizable marshes between Morro Bay, California, and Ensenada, Mexico, have been modified to some extent by human agencies, and three were completely filled. Marshland in California, never extensive, has recently been used for marina and industrial development, beach recreation, and housing. Many marshes in the upper portion of the range have been filled or diked.

Remaining tidal marshes are restricted to smaller lagoon and estuary systems along the coast. Most of them support only remnants of their former vegetation and lack plant diversity. In addition, water quality has been severely degraded by agricultural, residential, and industrial runoff. In some areas water has been diverted for irrigation or for municipal uses, lowering water levels and drying marshes. The low acreage of suitable marshland habitat limits the distribution of the bird's-beak and assures its continued rarity.

Conservation and Recovery

Critical habitat has been declared to include Carpinteria Marsh, the Santa Clara River mouth, Ormond Beach, Point Mugu, Upper Newport Bay, Los Penasquitos Lagoon, Tijuana Estuary in San Diego Bay, and the San Quintin marsh on the Baja California coast.

Because many California coastal marshes are on public lands, such as military bases or public beaches, the best interim strategy for protecting salt marsh bird's-beak is through habitat management. Navy lands at Camp Pendleton, which once supported colonies of the plant, could be rehabilitated for a reintroduction effort.

The Recovery Plan recommends protecting high marsh habitat that is on public lands by excluding unauthorized vehicles, imposing visitor restrictions, avoiding conversions of high marsh to low marsh, preventing destructive flooding of marshes, alleviating sewage effluent, preventing channelization of water through marshes, preventing saltwater intrusions into the aquifers feeding marshes, and protecting all shallow water impoundment systems in the marshes.

Recovery activities also include studies to assess the potential to successfully plant bird's-beak seed into other suitable habitat.

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/

References

Chuang, T. I., and L. R. Heckard. 1971. "Observations on Root-Parasitism in Cordylanthus (Scrophulariaceae)." American Journal of Botany 58:218-228.

Macdonald, K. 1977. "Coastal Salt Marsh." In M. G.Barbour and J. Major, eds., Terrestrial Vegetation of California. Wiley/Interscience, New York.

U. S. Fish and Wildlife Service. 1985. "Recovery Plan for the Salt Marsh Bird's-Beak." U. S. Fish and Wildlife Service, Portland.

Vanderwiler, J. M., and J. C. Newman. 1984. "Observations of Haustoria and Host Preference in Cordylanthus maritimus ssp. maritimus (Scrophulariaceae) at Mugu Lagoon." Madroño 31:185-186.