South San Francisco Bay Tidal Marsh 

Vegetation and Elevation Surveys—

Corkscrew Marsh, Bird Island, and Palo 

Alto Baylands, California, 1983

By James L. Orlando1, Judy Z. Drexler1, and Kent G. Dedrick2

1

U.S. Geological Survey, Placer Hall, 6000 J Street, Sacramento, California 95819-6129

2

California State Lands Commission, 100 Howe Ave., Sacramento, California 95825

Data Series 134

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2005

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested reference:

Orlando, J.L., Drexler, J.Z., and Dedrick, K.G., 2005, South San Francisco Bay tidal marsh vegetation and elevation surveys—Corkscrew marsh, Bird Island, and Palo Alto Baylands, Califoria, 1983: U.S. Geological Survey Data 

Series 134, 45 p.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Background.....................................................................................................................................................1

Purpose and Scope ..............................................................................................................................2

Plant Nomenclature .............................................................................................................................2

Acknowledgments................................................................................................................................2

Study Design and Methodology ..................................................................................................................2

Description of Study Sites...................................................................................................................2

Corkscrew Marsh ........................................................................................................................2

Bird Island.....................................................................................................................................2

Palo Alto Baylands ......................................................................................................................3

Description of Elevation and Vegetation Surveys ...........................................................................3

Corkscrew Marsh ........................................................................................................................4

Bird Island.....................................................................................................................................6

Palo Alto Baylands ......................................................................................................................6

GIS Data Analysis .................................................................................................................................7

Marsh Elevation and Vegetation Survey Results .....................................................................................8

Marsh Elevations ..................................................................................................................................8

Vegetation ..............................................................................................................................................8

References Cited............................................................................................................................................9

Figures

Figure 1. Map showing location of survey sites in South San Francisco Bay, California..........3

Figure 2. Aerial view of Corkscrew marsh and location of survey transects in 

South San Francisco Bay, California....................................................................................4

Figure 3. Aerial view of Bird Island marsh site and location of survey transects in 

South San Francisco Bay, California....................................................................................5

Figure 4. Aerial view of Palo Alto Baylands marsh site and location of survey transects in 

South San Francisco Bay, California....................................................................................6

Tables

Table 1. Plant nomenclature. ..............................................................................................................10

Table 2. Tidal benchmarks, lengths and bearings of survey transects conducted at 

Corkscrew marsh, Bird Island, and Palo Alto Baylands, South San Francisco Bay, 

California. ................................................................................................................................11

Table 3A. Elevations and percentage cover for Transect A–A′, Corkscrew marsh, 

South San Francisco Bay, Calfiornia .................................................................................12

Table 3B. Elevations and percentage cover for Transect B–B′, Corkscrew marsh, 

South San Francisco Bay, California .......................................................................15

Table 3C. Elevations and percentage cover for Transect C–C′, Corkscrew marsh, 

South San Francisco Bay, California .......................................................................18
iv

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 20

Table 4B. Elevations and percentage cover for Transect B rt–B rt′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 29

Table 4C. Elevations and percentage cover for Transect B lt–B lt′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 30

Table 4D. Elevations and percentage cover for Transect C rt–C rt′ Rt, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 31

Table 4E. Elevations and percentage cover for Transect Clt–C lt′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 32

Table 4F. Elevations and percentage cover for Transect D rt–D rt′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 33

Table 4G. Elevations and percentage cover for Transect D lt–D lt′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 34

Table 4H. Elevations and percentage cover for Transect E rt–E rt′ Rt, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 35

Table 4I. Elevations and percentage cover for Transect E lt–E lt′, Bird Island marsh, 

South San Francisco Bay, California................................................................................. 36

Table 5A. Elevations and percentage cover for Transect 2N–2N′, Palo Alto Baylands 

marsh, South San Francisco Bay, California................................................................... 37

Table 5B. Elevations and percentage cover for Transect 2N rt–2N rt′, Palo Alto Baylands

marsh, South San Francisco Bay, California................................................................... 38

Table 5C. Elevations and percentage cover for Transect 2N lt–2N lt′, Palo Alto Baylands 

marsh, South San Francisco Bay, California................................................................... 39

Table 5D. Elevations and percentage cover for Transect 2S–2S′, Palo Alto Baylands 

marsh, South San Francisco Bay, California................................................................... 40

Table 5E. Elevations and percentage cover for Transect 2S rt–2S rt′, Palo Alto Baylands 

marsh, South San Francisco Bay, California....................................................................41

Table 5F Elevations and percentage cover for Transect 2S lt–2S lt′, Palo Alto Baylands 

marsh, South San Francisco Bay, California................................................................... 42

Table 5G. Elevations and percentage cover for Transect 2A–2A′, Palo Alto Baylands 

marsh, South San Francisco Bay, California................................................................... 43

Table 5H. Elevations and percentage cover for Transect 2B–2B′, Palo Alto Baylands 

marsh, South San Francisco Bay, California................................................................... 44

Table 6. Total number of observations, observed range in elevation above MLLW, and 

median elevation for each plant species, South San Francisco Bay, California ..... 45
Conversion Factors, Vertical Datum, and Acronyms

Multiply By To obtain

meter (m) 3.281 foot

square meter (m2) 10.786 square foot (ft2)

Horizontal coordinate information is referenced to the “North American Datum of 1983 (NAD 

83).”

Vertical coordinate information is referenced to Mean Lower Low Water (MLLW) relative to the 

National Tidal Datum Epoch (1960-78).

Acronyms

GIS, Geographic Information System

MHW, mean high water

MLLW, Mean Lower Low Water

NOAA, National Oceanic and Atmospheric Administration
THIS PAGE INTENTIONALLY BLANK
Abstract

Changes in the topography and ecology of the San 

Francisco Bay Estuary (“Estuary”) during the past 200 years 

have resulted in the loss of nearly 80 percent of the historical salt marsh in the region. Currently, numerous projects are 

being undertaken by federal, state, and local governments in 

an attempt to restore wetland habitat and ecosystem function 

at a number of locations within the Estuary. Much information 

is needed concerning the historical topographic and ecologic 

characteristics of the Estuary to facilitate these restoration 

efforts. 

This report presents previously unpublished vegetation 

and elevation data collected in 1983 by the California State 

Lands Commission at Corkscrew marsh, Bird Island, and Palo 

Alto Baylands, all located in South San Francisco Bay. These 

precise and detailed elevation and plant surveys represent a 

snapshot of South Bay flora before invasion by the Atlantic 

smooth cordgrass, Spartina alterniflora. Such precise elevation data are rare for relatively undisturbed marshes in the 

San Francisco Bay; publication of these historical data may 

facilitate wetland restoration efforts. 

Marsh-surface and tidal-channel elevations were determined at a total of 962 stations by differential leveling to 

established tidal benchmark stations at each site and referenced to Mean Lower Low Water (MLLW) relative to the 

National Tidal Datum Epoch (1960–78). In addition, presence 

or absence of nine salt marsh species, percentage plant cover, 

and percentage bare soil were recorded for 1-m2 quadrats at 

648 stations where elevations were determined. 

Collectively, over the three sites, salt marsh vegetation ranged in elevation from 0.98 to 2.94 m above MLLW. 

S. foliosa and Salicornia virginica were the most frequently 

observed plant species. Atriplex patula, Deschampsia cespitosa, and Limonium californicum were each recorded at only 

one of the three sites. 

Introduction

Background

Beginning with the earliest European settlements, the 

land use and ecology of the San Francisco Bay Estuary 

(hereinafter, the “Estuary”) have undergone vast changes. 

Over the past 100 years, the population of the San Francisco 

Bay area has increased by about 1,500 percent, to over 6.8 

million people in 2003 (U.S. Census Bureau, 2004). Accompanying this dramatic rise in population has been a significant 

loss of natural habitat (Nichols and Wright, 1971; Dedrick, 

1989). It has been estimated that during the period since about 

1800, 79 percent of the salt marsh in the Estuary has been 

lost (Goals Project, 1999). Additional studies also indicate a 

similarly dramatic decrease in the number of tidal channels in 

the Estuary (Dedrick and Chu, 1993). Habitat loss within the 

Estuary is currently the subject of intense study by state and 

federal agencies and private organizations. Numerous habitat 

restoration projects are being conducted to reverse the trend of 

habitat loss. These projects will result in a significant increase 

in tidal marsh and open water acreage within the Estuary; one 

project alone, the South Bay Salt Pond Restoration Project, 

consists of 16,500 acres (Martin, 2004). 

A crucial factor in these restoration efforts is a sound 

understanding of the environmental conditions that are most 

conducive to plant colonization. Specifically, the elevation 

ranges with respect to the tide that are required for establishment and subsequent areal expansion of particular plant 

species must be fully understood if restoration is to be 

successful. 

South San Francisco Bay Tidal Marsh Vegetation and 

Elevation Surveys—Corkscrew Marsh, Bird Island, and 

Palo Alto Baylands, California, 1983 

By James L. Orlando, Judy Z. Drexler, and Kent G. Dedrick
Purpose and Scope

This report presents previously unpublished, detailed, 

vegetation and elevation survey data collected by the California State Lands Commission and Dr. H. Thomas Harvey at 

three relatively undisturbed salt marsh areas along the southwestern shore of San Francisco Bay, California, in August and 

November of 1983. The U.S. Geological Survey is publishing 

these data now because of the historical and ecological importance of a highly precise elevation data set for common saltmarsh plant species in South San Francisco Bay. In particular, 

these data represent a rare picture of South Bay salt-marsh 

flora before invasion by the Atlantic smooth cordgrass, Spartina alterniflora (see Callaway and Josselyn [1992] for sphere 

of influence of S. alterniflora as of 1992). 

The data presented in this report consist of marsh-surface 

and tidal-channel elevations at a total of 962 stations that were 

measured above local Mean Lower Low Water (MLLW) and 

were based on the National Tidal Datum Epoch (1960–78). In 

addition, supplementary data consisting of percentage cover 

for bare ground and nine plant species were recorded at 648 

stations. 

Plant Nomenclature

In the field notes taken by Drs. Kent Dedrick (California 

State Lands Commission) and H. Thomas Harvey (private consultant), the plant species observed were listed by the following names: Atriplex patula, Deschampsia, cordgrass, Frankenia, Jaumea, Grindelia, Limonium, pickleweed, and saltgrass. 

Because these names, with the exception of A. patula, are 

either incomplete and (or) confusing (that is, only genera 

are listed for some and only common names for others), the 

following procedure was used to determine the actual plant 

species denoted by each of the names. First, the geographic 

ranges of particular species matching the common names and 

genera of the above were obtained from The Jepson Manual 

(Hickman, 1993). Next, all field notes were checked for any 

information regarding unusual or rare plant occurrences. 

Because there were no notes regarding any rare or unusual 

species being sighted, it was decided that the species recorded 

in the notes likely signify the common marsh plants found in 

the low, middle, and high salt marsh zones of South San Francisco Bay. Baye and others (2000), a reference describing the 

tidal marsh plant communities in the San Francisco Estuary, 

was consulted in determining species names for each of the 

plants (table 1). 

Acknowledgments

This report was funded through the U.S. Geological Survey’s Federal Matching Funds Program. The data presented in 

this report are the result of the hard work and 

dedication of Kent G. Dedrick, who personally and professionally sought to protect the San Francisco Bay Estuary, and 

without whom these data would not have been preserved. 

His death was a great loss to many. The authors also wish to 

acknowledge personnel of the California State Lands Commission who conducted the original elevation surveys described 

herein as well as the late Dr. H. Thomas Harvey, Harvey and 

Stanley Associates, who contributed greatly to the original 

project through his expertise and hard work. 

Study Design and Methodology

Description of Study Sites

Data were examined for three areas of relatively undisturbed salt marsh located along the southern shores of San 

Francisco Bay. The marsh areas surveyed are located on Bair 

Island (hereinafter referred to as Corkscrew marsh), Bird 

Island marsh (hereinafter referred to as Bird Island), and at the 

Palo Alto Baylands marsh (hereinafter referred to as Palo Alto 

Baylands) (fig. 1). Both Corkscrew marsh and Bird Island are 

currently part of the 30,000-acre Don Edwards San Francisco 

Bay National Wildlife Refuge, whereas the Palo Alto marsh 

site is located within the 1,940-acre Palo Alto Baylands Preserve. 

Corkscrew Marsh

The area consists of a 31.1-acre tract of marsh bordered 

by Corkscrew Slough on the north, west, and east, and by a 

former salt evaporation pond to the south (fig. 2). The area is 

of predominantly low relief and is to a great extent affected 

by tidal action. There are numerous small, shallow channels 

that extend into the marsh from Corkscrew Slough. The area 

became part of the Don Edwards San Francisco Bay National 

Wildlife Refuge in 1998.

Bird Island

Bird Island is located northeast of the Corkscrew marsh 

site and is separated from the bay margin by a narrow slough. 

The area consists of approximately 87 acres of salt marsh and 

is elongated in an east–west direction (fig. 3). Numerous narrow channels enter the island from the south and extend northward. Generally, these channels do not completely traverse 

the island. The northern edge of the island is exposed directly 

to San Francisco Bay and is subject to overtopping by wind 

driven waves. The marsh is also part of the Don Edwards San 

Francisco Bay National Wildlife Refuge.

   Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
Palo Alto Baylands

The marsh surveyed at this site is directly north of the 

Palo Alto yacht harbor and occupies approximately 90 acres 

within the larger Palo Alto Baylands Preserve (fig. 4). The area 

is currently open to the public and is immediately adjacent to 

the Lucy Evans Baylands Nature Preserve Interpretive Center. 

A small number of shallow channels enter the area from San 

Francisco Bay to the north. Two boardwalks crisscross the 

area, one providing public access to the marsh and the other 

for restricted access to power transmission lines, which traverse the marsh. The area is open to tidal influence.

Description of Elevation and Vegetation Surveys

Elevation surveys performed at each of the three sites 

were conducted by the California State Lands Commission. 

Standard differential leveling survey techniques were used in 

all instances (U.S. Army Corps of Engineers, 2002). Precise 

elevations were determined by differential leveling relative 

to tidal benchmarks established by the National Oceanic and 

Atmospheric Administration National Ocean Service in 1976 

(National Oceanic and Atmospheric Administration, National 

Ocean Service, 2005). A list of tidal benchmarks used to determine elevations appears in table 2. Elevations presented in 

this report are referenced to Mean Lower Low Water (MLLW) 

for the relevant tidal benchmark stations. MLLW is defined 

as the average of the lower low water height of each tidal day 

observed during a tidal epoch. Elevations are calculated from 

the National Tidal Datum Epoch (1960–78) because corrections to the latest tidal epoch (1983–2001) are not available for 

all benchmark stations.

Palo Alto

Baylands

Corkscrew

Marsh

San Francisco

Bird Island

San Francisco Bay

Pacific Ocean

Base from U.S. Geological Survey digital data,

1:500,000, downloaded 2003

37°

25'

37°

30'

37°

35'

37°

40'

37°

45'

37°

50'

0 2 4 8

0 2 4 8 Kilometers

Miles

EXPLANATION

Marsh survey area

Don Edwards San Francisco Bay

National Wildlife Refuge

Area of

map

C ALIFORNIA

Pacific Ocean

N

Figure 1. Location of survey sites in South San Francisco Bay. 

Study Design and Methodology   
At each site, plant presence or absence and percentage 

cover for plant species and soil were visually estimated to the 

nearest five percent within 1-m2 quadrats centered along the 

same transects as the elevation surveys. Plant species noted 

included Atriplex patula L. (variety unknown; common name: 

Spear oracle), Jaumea carnosa Less. (common name: fleshy 

Jaumea), Spartina foliosa Trin. (common name: California 

cordgrass), Distichlis spicata L. (variety unknown; common 

name: saltgrass), Limonium californicum Boiss. (common 

name: California sea lavender), Salicornia virginica L. (common name: pickleweed), Deschampsia cespitosa L. (subspecies unknown; common name: tufted hairgrass), Frankenia 

salina Molina (common name: alkali heath), and Grindelia 

stricta DC. (variety unknown; common name: gumplant). The 

total percentage cover, when all plant species and bare ground 

are summed, equals more than 100 percent at some stations 

because of the additive effect of multiple plant canopies. The 

presence of vegetation or soil at less than five percent of the 

quadrat area was noted as “trace” in the field notes and within 

this report. Typically, data were not collected at stations coincident with waterways, and not all plant species were observed 

at each site.

Corkscrew Marsh

The initial purpose of this survey was to link plant 

survey data collected in 1975 to standard tidal benchmarks to 

accurately determine the location of various plant species with 

respect to mean high water (MHW). Because of the disturbance of the original survey markers emplaced in 1975, this 

Image from U.S. Geological Survey and

Air Photo USA, LLC., February 2004

Salt Evaporation

Pond

A

A'

C B

C'

C B' orkscrew Slou

gh

0 250 500 1,000 Feet

0 125 250 500 Meters

EXPLANATION

Marsh survey area Survey transect line

Figure 2. Aerial view of Corkscrew marsh and location of survey transects in South San Francisco Bay, California.

   Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
link could not be accomplished. Therefore, a new elevation–

vegetation survey was conducted by the California State Lands 

Commission. This survey was conducted during November 

21–22, 1983, over the same general area of marsh surveyed in 

the 1975 study and consisted of three separate transects (Transects A–C, fig. 2). Each transect originated from a separate 

point located on an elevated dirt roadway at the southern end 

of the marsh and extended to the bank of Corkscrew Slough. 

The lengths of each transect and bearing from origination 

point relative to true north are listed in table 2.

Land surface elevations were determined by differential 

leveling relative to five tidal benchmarks established by the 

National Oceanic and Atmospheric Administration (NOAA), 

National Ocean Service in 1976, as station 941-4505 (National 

Oceanic and Atmospheric Administration, National Ocean 

Service, 2005). The locations of individual stations along 

each transect were chosen in the field on the basis of observed 

changes in elevation and (or) vegetation patterns. At each 

station, land surface elevation was determined and the percentage cover of bare ground and plant species was noted for 1-m2

quadrats centered along the transect line. Data collected during 

this survey are presented in tables 3A–C.

Image from U.S. Geological Survey and

Air Photo USA, LLC., February 2004

Bird Island

A'

E rt'

E rt

D rt'

C rt'

B rt' 

A

B lt'

D lt'

C lt'

E lt'

E lt

D rt

D lt

C rt

C lt

B rt

B lt

0 500 1,000 2,000 Feet

0 120 240 480 Meters

EXPLANATION

Marsh survey area Survey transect line

San Francisco Bay

Figure 3. Aerial view of Bird Island marsh site and location of survey transects in South San Francisco Bay, California. 

Study Design and Methodology   
Bird Island

An elevation survey of Bird Island was conducted during 

August 16–19, 1983, by the California State Lands Commission. The survey consisted of one main transect (A–A′) 

running east to west across the entire island and four pairs of 

shorter north and south transects set perpendicular to the main 

transect (fig. 3 and table 2). Each of the shorter transects began 

at the intersection with transect A–A′ and extended north or 

south to the edge of the island. Elevations of stations on the 

eastern half of transect A and on transects B and C were determined by differential leveling to the five tidal benchmarks of 

NOAA station 941-4486, whereas four benchmarks of station 

941-4486 were used to determine all other elevations. 

Plant presence or absence and the percentage cover data 

for plant species and bare soil were collected during June 

11–15, 1984, by Kent G. Dedrick (see Acknowledgements) 

and H. Thomas Harvey along the main east–west transect and 

one of the four pairs of perpendicular transects, and at the 

same stations where elevation data were previously acquired 

(tables 4A–I).

Palo Alto Baylands

This survey was conducted on November 16, 1983, and 

consisted of eight separate transects covering two sections 

of marsh approximately 280 m apart (fig. 4 and table 2). Six 

transects were conducted in the eastern portion of the site and 

consisted of two main north and south transect lines (2N–2N′ 

and 2S–2S′) with shorter, parallel lines spaced 6.1 m on either 

side. The area in which these transects were conducted borders 

a section of reclaimed marsh, which is a former disposal site 

for dredge spoils from the nearby Palo Alto yacht harbor. We 

Image from U.S. Geological Survey and

Air Photo USA, LLC., February 2004

2N rt'

2A'

2B'

2N lt'

2N lt, 2N, 2N rt

2S lt, 2S, 2S rt

2N' 2A 2B

Palo Alto Baylands

Interperative Center

San Francisco Bay

2S rt' 2S lt'

2S'

Transect

2

Origins

Boardwalk

EXPLANATION

Survey transect

0 75 150 300 Feet

0 35 70 140 Meters

Figure 4. Aerial view of Palo Alto Baylands marsh site and location of survey transects ion South San Francisco Bay, California.

   Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
concluded, after examining historical topographical maps, that 

dredge spoils were not likely deposited on the area of marsh 

surveyed; however, this could not be determined definitively. 

The western-most surveys conducted at this site consisted 

of two relatively short transects (2A–2A′ and 2B–2B′) extending perpendicularly from a boardwalk that traverses the marsh. 

The area in which these surveys took place is a historical salt 

marsh. The elevation survey was conducted by California State 

Lands Commission personnel. Elevations were determined by 

differential leveling to the four tidal benchmarks of NOAA 

station 941-4525. 

Plant presence or absence and the percentage cover of 

plant species and bare soil were noted within 1-m2 quadrats 

centered along each transect line at each station. The plant 

survey was carried out by Dr. H. Thomas Harvey of Harvey 

& Stanley Associates (formerly of Alviso, California) and the 

data are presented in tables 5A–H.

GIS Data Analysis

Initially, the data presented in this report were in the form 

of print copies of the original field notes and research summaries produced in 1983 or later. The first step toward preparing 

the data for publication was to enter the relevant elevation and 

vegetation survey data into an electronic spreadsheet so that it 

could be analyzed more efficiently.

We also determined that analysis of the data would 

benefit from spatial display within a Geographic Information 

System (GIS). In order to accomplish this, the geographic 

coordinates of each survey point needed to be calculated from 

the original survey data. The original survey notes varied 

greatly in detail for the three survey sites and as such, spatially locating the individual survey points was accomplished 

through a multistep process. 

In this process, the survey notes were first examined for 

any spatially significant information describing the location of 

transect starting points such as latitude and longitude coordinates, bearings and distances to established benchmarks, 

or written descriptions referencing physical landmarks. This 

information was then used to plot an approximate position 

for the starting point of each transect line in the GIS. Next, 

the transect bearing, estimated from information in the survey 

notes, was combined with the surveyed distances between 

transect stations to construct each full transect line. The 

complete transect lines were then overlain on georeferenced, 

digital, high-resolution aerial photographs from 2004 of each 

of the survey sites. The location of each station along each 

transect was then visually evaluated relative to the aerial 

photographs to determine whether its position was correct and 

matched any comments contained in the survey notes. Specifically, stations noted as occurring at or near waterways or 

shorelines were compared with such observable features in the 

digital photographs. Adjustments were made to the locations 

of the transect lines until the best possible fit was achieved.

Given the nature of the original survey data, the horizontal locations of individual transect stations are estimated and 

are not detailed in this report. It is, therefore, unlikely that 

follow-up surveys will be possible. However, this in no way 

detracts from the value of the elevation data contained herein. 

It is evident from the original field notes that these values 

were determined through rigorous surveying procedures using 

stable and accurate tidal benchmarks. 

The survey transects and individual stations were displayed in the GIS and attributed using the plant abundance 

data contained in the survey notes. Survey stations were then 

displayed in the GIS together with the plant attribute data to 

explore relationships between plant location, abundance, and 

elevation. All GIS procedures were carried out using the software program ArcGIS 9.0 (ESRI, Redlands, CA). For display 

purposes, all data were placed in the Universal Transverse 

Mercator Zone 10 projection and horizontally referenced to 

the North American Datum of 1983 (NAD83). 

Marsh Elevation and Vegetation Survey 

Results

Marsh Elevations

Marsh surface and tidal channel elevations were collected 

by the California State Lands Commission in 1983 at a total of 

962 stations from three areas of salt marsh located along the 

southern shore of San Francisco Bay (tables 3–5). Plant presence or absence and percentage cover data were collected at 

648 of these stations. An examination of these stations shows 

that marsh surface and tidal channel elevations ranged from 

0.98 to 2.94 m, with a median value of 2.18 m, above MLLW. 

In a breakdown of the data from each of the sites (Corkscrew marsh, Bird Island, and Palo Alto Baylands), marsh 

surface and tidal channel elevations for stations with plant 

cover data ranged from 1.19 to 2.55 m, 0.98 to 2.52 m, and 

1.45 to 2.94 m above MLLW at each site, respectively. The 

median elevation above MLLW recorded at each site was 2.24 

m at Corkscrew Slough, 2.04 m at Bird Island, and 2.51 m at 

Palo Alto Baylands.

Vegetation

The percentage coverage of nine plant species and bare 

ground was recorded at 648 stations at the three salt marsh 

sites. S. foliosa and S. virginica were the most frequently 

observed species. The total number of observations, elevation 

ranges, and median elevation values for bare ground and each 

plant species are presented in table 6. 

Marsh Elevation and Vegetation Survey Results 
The plants observed, and their abundances, varied to 

some extent on a site by site basis. At Corkscrew marsh and 

Bird Island, S. foliosa followed by S. virginica were the two 

most frequently observed plants, whereas at Palo Alto Baylands, the order was reversed (table 6). A. patula was observed 

only at Palo Alto Baylands, whereas D. cespitosa and L. 

californicum were recorded only at Bird Island. Total numbers 

of observations, elevation ranges, and median elevation values 

for bare ground and each plant type on a site by site basis are 

presented in table 6. 

References Cited

Baye, P.R., Faber, P.M., and Grewell, B., 2000, Tidal marsh 

plants of the San Francisco Estuary, in Olofson, P.R. (ed.), 

Goals Project, Bayland ecosystem species and community 

profiles, Life histories and environmental requirements of 

key plants, fish, and wildlife. Prepared by the San Francisco 

Bay Area Wetlands Ecosystems Goals Project: Oakland, 

Calif., San Francisco Bay Regional Water Quality Control 

Board. 

Callaway, J.C., and Josselyn, M.N., 1992, The introduction 

and spread of smooth cordgrass (Spartina alterniflora) in 

South San Francisco Bay: Estuaries, v. 15, no. 2, 

p. 218–226.

Dedrick, K.G., 1989, San Francisco Bay tidal marshland acreages: recent and historic [sic] values, in Magoon, O.T. and 

others, eds., Proc. 6th Symposium on Coastal and Ocean 

Management (Coastal Zone-89), July 11–14, 1989, Charleston, South Carolina: New York, N.Y., American Society of 

Civil Engineers, p. 383–398.

Dedrick, K.G., and Chu, L.T., 1993, Historical atlas of tidal 

creeks San Francisco Bay, California, in Magoon, O.T. and 

others, eds., Proc. 8th Symposium on Coastal and Ocean 

Management (Coastal Zone-93), July 19–23, 1993, New 

Orleans, Louisiana: New York, N.Y., American Society of 

Civil Engineers, p. 2464–2478.

Goals Project, 1999, Baylands Ecosystem Habitat Goals—a 

report of habitat recommendations prepared by the San 

Francisco Bay Area Wetlands Ecosystem Goals Project, 

First Reprint: San Francisco, Calif. and Oakland, Calif., 

U.S. Environmental Protection Agency and San Francisco 

Bay Regional Water Quality Control Board. 

Hickman, J.C., 1993, The Jepson manual—higher plants of 

California: Berkeley, Calif., University of California Press, 

1400 p. 

Martin, G., 2004, A tall order: the art and science of wetland 

restoration: Bay Nature, October–December, p. 18–32.

National Oceanic and Atmospheric Administration, National 

Ocean Service, [2005], Tidal benchmark sheets 9414483, 

9414486, 9414505, and 9414525, accessed January 18, 

2005, at http://co-ops.nos.noaa.gov/bench

Nichols, D.R., and Wright, N.A., 1971, Preliminary map of 

historic margins of marshland, San Francisco Bay, 

California: U.S. Geological Survey, Open-File map.

U.S. Army Corps of Engineers, 2002, Engineering and 

design—geodetic and control surveying, Chapter 6, 

accessed January 18, 2005, at http://www.usace.army.mil/

inet/usace-docs/eng-manuals/em1110-1-1004/toc.htm

U.S. Census Bureau [2004], United States Census Population 

Estimates 2003: U.S. Census Bureau [digital data], accessed 

October 9, 2004, at http://www.census.gov

   Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
TABLES
Plant name as orininally 

apears in field notes Common plant name Corresponding proper name

Atriplex patula Spear oracle Atriplex patula L.

Cordgrass Cordgrass Spartina foliosa Trin.

Deschampsia Tufted harigrass Deschampsia cespitosa L.

Frankenia Alkali heath Frankenia salina Molina

Grindelia Gumplant Grindelia stricta DC.

Jaumea Fleshy Jaumea Jaumea carnosa Less.

Limonium California sea lavender Limonium californicum Boiss.

Pickleweed Pickleweed Salicornia virginica L.

Saltgrass Saltgrass Distichlis spicata L.

Table 1. Plant nomenclature.

10 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
Tidal benchmark 

identification number

Tidal benchmark 

reference latitude 

(degrees/minutes/

seconds)

Tidal benchmark 

reference longitude 

(degrees/minutes/

seconds)

Transect length 

(meters) 

Transect bearing from 

true north (degrees)

Corkscrew marsh

Transect A 941-4505 37°30′30′′ 122°12′36′′ 303.3 346.3

Transect B 941-4505 37°30′30′′ 122°12′36′′ 376.5 4.5

Transect C 941-4505 37°30′30′′ 122°12′36′′ 237.0 347.5

Bird Island

Transect A 941-4483 37°33′06′′ 122°14′36′′ 1,299.7 273.0

Transect A 941-4486 37°32’42′′ 122°13′18′′ 1,288.7 273.0

Transect B rt 941-4483 37°33′06′′ 122°14′36′′ 18.6 3.0

Transect B lt 941-4483 37°33′06′′ 122°14′36′′ 86.9 183.0

Transect C rt 941-4483 37°33′06′′ 122°14′36′′ 141.7 3.0

Transect C lt 941-4483 37°33′06′′ 122°14′36′′ 148.7 183.0

Transect D rt 941-4486 37°32′42′′ 122°13′18′′ 105.8 3.0

Transect D lt 941-4486 37°32′42′′ 122°13′18′′ 192.3 183.0

Transect E rt 941-4486 37°32′42′′ 122°13′18′′ 125.0 3.0

Transect E lt 941-4486 37°32′42′′ 122°13′18′′ 141.7 183.0

Palo Alto Baylands

Transect 2N 941-4525 37°27′30′′ 122°06′18′′ 138.7 356.0

Transect 2N rt 941-4525 37°27′30′′ 122°06′18′′ 91.4 356.0

Transect 2N lt 941-4525 37°27′30′′ 122°06′18′′ 91.4 356.0

Transect 2S 941-4525 37°27′30′′ 122°06′18′′ 125.0 176.0

Transect 2S rt 941-4525 37°27′30′′ 122°06′18′′ 30.5 176.0

Transect 2S lt 941-4525 37°27′30′′ 122°06′18′′ 30.5 176.0

Transect 2A 941-4525 37°27′30′′ 122°06′18′′ 30.5 211.0

Transect 2B 941-4525 37°27′30′′ 122°06′18′′ 45.7 29.0

Table 2. Tidal benchmarks, lengths and bearings of survey transects conducted at Corkscrew marsh, Bird Island, and Palo Alto Baylands, 

South San Francisco Bay, California.

[Horizontal datum NAD 27; rt, right; lt, left]

Table 2 11
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 3.51 nd nd nd nd nd nd

2 4.06 2.43 0 0 0 0 100 0

3 8.27 2.12 nd nd nd nd nd nd

4 11.17 2.33 0 0 0 0 100 0

5 24.57 2.33 0 0 0 0 100 0

6 24.95 2.14 0 0 0 0 100 0

7 25.28 2.29 nd nd nd nd nd nd

8 36.52 2.38 0 0 0 0 100 0

9 43.39 2.29 0 0 0 0 100 0

10 45.91 1.44 nd nd nd nd nd nd

11 46.42 2.11 0 0 0 0 100 0

12 48.60 2.31 0 0 0 0 100 5

13 50.48 2.28 nd nd nd nd nd nd

14 51.56 1.79 nd nd nd nd nd nd

15 52.41 2.22 0 0 0 0 100 5

16 53.16 2.26 0 0 0 0 100 10

17 53.99 1.85 nd nd nd nd nd nd

18 54.99 2.19 0 0 0 0 100 15

19 64.99 2.28 0 0 0 0 100 10

20 72.04 2.25 0 0 0 0 90 20

21 73.19 1.98 nd nd nd nd nd nd

22 73.59 2.06 0 0 0 100 0 10

23 79.63 2.29 0 0 0 100 0 20

24 83.51 2.19 0 0 0 0 100 15

25 83.80 1.98 nd nd nd nd nd nd

26 84.06 2.22 0 0 0 0 90 15

27 86.53 2.29 0 0 0 0 80 20

28 88.84 2.22 0 0 0 0 90 5

29 89.43 2.00 nd nd nd nd nd nd

30 90.27 2.18 0 0 0 0 40 60

31 91.26 1.90 nd nd nd nd nd nd

32 92.17 2.20 0 0 0 0 40 50

33 93.34 2.00 80 0 0 0 0 20

34 94.31 1.98 nd nd nd nd nd nd

35 95.13 2.23 0 0 0 0 70 30

36 103.36 2.35 0 70 0 0 0 10

37 110.88 2.18 0 90 10 0 0 0

38 111.25 1.64 nd nd nd nd nd nd

39 112.89 2.18 nd nd nd nd nd nd

Table 3A. Elevations and percentage cover for Transect A–A′, Corkscrew marsh, South San Francisco Bay, Calfiornia. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

12 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

40 116.92 2.38 0 100 0 0 0 Trace

41 120.83 2.38 0 100 0 0 0 0

42 121.40 1.76 nd nd nd nd nd nd

43 123.00 1.52 nd nd nd nd nd nd

44 123.28 2.31 0 90 0 10 0 0

45 126.44 2.38 0 90 0 10 0 0

46 129.74 2.40 0 100 0 0 0 0

47 130.13 1.64 nd nd nd nd nd nd

48 132.70 1.70 20 0 0 0 0 80

49 133.13 2.12 0 100 0 0 0 20

50 134.27 2.01 20 0 0 0 0 80

51 134.75 2.32 0 80 0 20 0 20

52 140.00 2.30 0 100 0 0 0 15

53 149.79 2.33 0 80 0 0 20 30

54 150.14 1.95 nd nd nd nd nd nd

55 150.67 2.31 0 80 0 0 30 20

56 158.26 2.34 0 90 0 0 0 20

57 168.35 2.42 0 30 40 30 0 0

58 168.90 1.74 0 0 0 0 0 100

59 170.43 1.95 0 0 0 0 0 100

60 171.25 0.83 nd nd nd nd nd nd

61 172.89 0.92 nd nd nd nd nd nd

62 173.52 1.53 0 0 0 0 0 100

63 175.18 2.12 10 90 0 0 0 10

64 176.63 2.32 0 100 0 0 0 Trace

65 185.47 2.35 0 100 0 0 0 10

66 191.75 2.29 0 100 0 0 0 15

67 194.11 1.92 nd nd nd nd nd nd

68 195.04 2.15 0 60 0 0 0 30

69 198.27 2.25 10 0 0 0 90 10

70 201.19 2.22 20 0 0 0 80 10

71 202.65 1.84 80 0 0 0 0 20

72 203.23 1.84 80 0 0 0 0 20

73 203.83 2.16 0 0 0 0 100 30

74 206.61 2.28 0 0 0 0 80 20

75 207.28 1.86 nd nd nd nd nd nd

76 208.46 1.94 nd nd nd nd nd nd

77 209.01 2.20 nd nd nd nd nd nd

78 211.70 2.27 0 0 0 0 100 15

79 213.74 2.22 0 0 0 0 80 20

80 214.43 2.03 70 0 0 0 0 30

Table 3A. Elevations and percentage cover for Transect A–A′, Corkscrew marsh, South San Francisco Bay, CalfiorniaContinued. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

Table 3A 13
14 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

81 215.80 2.16 nd nd nd nd nd nd

82 220.40 2.27 0 0 0 0 100 10

83 230.36 2.36 0 0 0 0 100 25

84 238.31 2.31 0 70 0 0 30 5

85 244.18 2.23 0 20 0 80 Trace 0

86 244.77 1.13 nd nd nd nd nd nd

87 245.44 1.19 nd nd nd nd nd nd

88 246.76 2.10 0 80 0 0 0 40

89 249.13 2.24 nd nd nd nd nd nd

90 249.96 2.01 nd nd nd nd nd nd

91 250.59 2.24 0 90 0 0 0 10

92 260.11 2.33 0 10 0 90 0 Trace

93 265.27 2.28 0 60 0 0 0 35

94 266.49 2.13 0 30 0 0 0 60

95 267.43 2.29 0 80 0 0 0 20

96 274.63 2.32 0 90 0 5 5 0

97 285.06 2.29 0 0 0 90 10 5

98 285.92 1.90 80 0 0 0 0 20

99 286.87 2.26 0 20 0 70 10 10

100 288.45 2.30 0 50 0 30 10 5

101 289.28 1.66 70 0 0 0 0 30

102 289.85 1.70 nd nd nd nd nd nd

103 290.75 2.23 nd nd nd nd nd nd

104 292.89 2.20 0 0 0 0 80 20

105 296.31 2.16 nd nd nd nd nd nd

106 299.64 1.78 0 0 0 0 20 80

107 300.06 0.94 nd nd nd nd nd nd

108 303.27 0.56 nd nd nd nd nd nd

Table 3A. Elevations and percentage cover for Transect A–A′, Corkscrew marsh, South San Francisco Bay, CalfiorniaContinued. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less.

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 3.47 nd nd nd nd nd nd

2 2.31 3.11 nd nd nd nd nd nd

3 4.08 2.47 10 0 0 0 90 0

4 5.72 2.30 0 0 0 0 100 0

5 6.22 2.04 0 0 0 0 100 0

6 6.72 2.00 0 0 0 0 100 0

7 6.92 2.35 0 0 0 0 100 0

8 11.26 2.40 0 0 0 0 100 0

9 24.89 2.40 0 0 0 0 100 0

10 36.53 2.41 0 70 0 30 0 0

11 48.70 2.36 0 30 0 30 40 0

12 56.77 2.33 0 25 0 0 75 0

13 59.13 2.23 0 10 0 0 90 0

14 61.65 2.28 0 10 0 0 90 0

15 62.51 2.10 0 0 0 0 100 0

16 63.01 2.26 0 0 0 0 100 0

17 65.73 2.27 0 0 0 0 100 0

18 68.10 2.24 0 0 0 0 100 0

19 68.73 1.97 0 0 0 0 100 0

20 69.78 2.21 0 0 0 0 100 0

21 73.16 2.22 0 0 0 0 100 5

22 73.84 2.06 10 0 0 0 90 10

23 74.68 2.08 10 0 0 0 90 5

24 75.41 2.26 0 0 0 0 100 0

25 76.43 2.24 0 0 0 0 100 10

26 77.61 2.24 0 0 0 0 100 10

27 78.09 2.09 0 0 0 0 100 0

28 78.50 2.20 0 0 0 0 100 0

29 79.83 2.17 0 0 0 0 20 70

30 80.42 2.09 40 0 0 0 30 30

31 81.34 2.23 0 0 0 0 100 0

32 86.24 2.31 0 30 0 0 70 5

33 92.34 2.35 0 60 0 0 40 0

34 96.67 2.30 0 100 0 0 0 0

35 98.53 2.20 0 0 0 0 0 10

36 99.11 1.94 60 0 0 0 0 40

37 100.23 1.93 nd nd nd nd nd nd

38 100.53 2.14 0 60 0 0 0 40

39 103.23 2.29 0 90 0 0 5 0

40 106.96 2.24 0 75 0 0 25 0

41 107.74 1.99 80 0 0 0 0 20

42 108.66 2.01 50 0 0 0 0 50

43 109.34 2.24 30 30 0 0 40 40

44 110.58 2.19 nd nd nd nd nd nd

45 113.10 2.26 0 75 0 0 20 15

46 119.24 2.35 0 90 0 5 5 0

47 125.33 2.23 10 40 0 0 0 50

48 130.56 2.28 0 70 0 0 10 30

49 136.88 2.33 0 80 0 0 20 0

50 142.36 2.34 0 95 0 0 5 0

51 145.62 2.17 0 80 0 0 0 20

Table 3B. Elevations and percentage cover for Transect B–B′, Corkscrew marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

Table 3B 15
16 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less.

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

52 146.39 1.65 0 0 0 0 0 80

53 147.11 1.52 95 0 0 0 0 5

54 147.59 1.26 95 0 0 0 0 5

55 148.01 1.27 nd nd nd nd nd nd

56 148.99 2.32 0 100 0 0 0 0

57 153.74 2.32 0 100 0 0 0 5

58 157.52 2.30 5 95 0 5 0 10

59 157.87 1.76 0 90 0 0 10 0

60 158.67 1.85 nd nd nd nd nd nd

61 159.11 2.13 0 80 0 0 0 25

62 163.30 2.27 0 80 0 0 0 0

63 166.73 2.21 0 60 0 0 40 0

64 168.74 2.15 0 50 0 10 20 50

65 169.49 1.83 nd nd nd nd nd nd

66 171.06 1.88 0 0 0 0 0 30

67 171.63 2.23 0 75 0 0 0 0

68 174.48 2.28 25 75 0 0 0 0

69 175.88 2.25 0 90 0 0 0 7

70 176.14 1.89 0 90 0 0 0 0

71 177.86 1.85 70 0 0 0 0 30

72 178.24 2.13 0 80 0 0 20 10

73 182.93 2.26 0 90 0 0 10 20

74 193.50 2.24 0 100 0 0 0 25

75 202.37 2.31 0 30 0 40 30 0

76 205.25 2.32 0 40 0 55 5 10

77 206.35 2.10 nd nd nd nd nd nd

78 206.95 2.28 0 80 0 10 10 20

79 212.77 2.24 0 0 0 40 60 30

80 218.60 2.23 0 0 0 0 80 30

81 219.85 2.12 nd nd nd nd nd nd

82 222.41 2.23 0 0 0 0 90 15

83 224.46 2.38 30 0 0 0 70 20

84 224.85 2.10 nd nd nd nd nd nd

85 225.82 2.11 50 0 0 0 10 50

86 226.86 2.15 0 0 0 40 50 20

87 228.48 2.21 0 0 0 75 30 25

88 230.63 2.25 0 0 0 0 100 5

89 234.23 2.26 0 0 0 0 80 10

90 237.49 2.24 0 0 0 0 80 5

91 237.89 2.10 nd nd nd nd nd nd

92 238.74 2.23 0 0 0 10 90 5

93 245.17 2.22 0 0 0 0 80 30

94 252.55 2.19 0 0 0 0 90 15

95 256.01 2.18 10 0 0 0 75 30

96 256.46 2.01 nd nd nd nd nd nd

97 258.12 2.01 50 0 0 0 0 50

98 259.37 2.10 0 0 0 0 90 30

99 262.41 2.15 10 0 0 0 90 30

100 264.20 2.15 0 0 0 0 95 30

101 264.92 1.87 nd nd nd nd nd nd

Table 3B. Elevations and percentage cover for Transect B–B′, Corkscrew marsh, South San Francisco Bay, CaliforniaContinued. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]
CA-3339 Heading 1 17

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less.

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

102 267.05 1.86 nd nd nd nd nd nd

103 267.34 2.00 nd nd nd nd nd nd

104 269.06 2.24 0 0 0 0 70 40

105 280.22 2.30 20 0 0 0 80 20

106 286.46 2.32 0 0 0 0 90 35

107 290.66 2.23 0 0 0 0 90 35

108 291.28 1.74 90 0 0 0 0 10

109 292.14 1.76 90 0 0 0 0 10

110 292.51 2.14 0 80 0 0 20 20

111 297.04 2.25 0 50 0 0 25 25

112 303.63 2.26 0 100 0 0 0 40

113 309.43 2.27 0 100 0 0 0 30

114 312.50 2.28 0 100 0 0 0 0

115 312.98 1.77 nd nd nd nd nd nd

116 313.49 1.80 30 0 0 0 0 70

117 314.03 2.20 50 0 0 0 50 20

118 314.91 1.86 90 0 0 0 0 10

119 315.47 1.80 90 0 0 0 0 10

120 315.80 2.09 10 10 0 0 0 80

121 318.29 2.26 0 100 0 0 0 5

122 328.99 2.33 0 40 0 60 5 0

123 335.07 2.31 0 100 0 10 0 0

124 335.56 2.13 nd nd nd nd nd nd

125 336.04 2.30 0 60 0 40 0 15

126 341.44 2.30 0 20 0 80 5 0

127 347.52 2.32 0 30 0 0 40 40

128 358.73 2.32 0 100 0 0 5 0

129 362.46 2.24 0 90 0 10 0 5

130 364.64 2.21 0 95 0 5 0 30

131 365.35 2.05 40 40 0 0 0 40

132 366.91 1.98 0 0 0 0 0 60

133 368.47 2.01 15 0 0 0 5 80

134 370.30 1.98 nd nd nd nd nd nd

135 372.62 2.08 0 0 0 0 30 40

136 374.25 1.31 95 0 0 0 0 5

137 376.54 0.99 nd nd nd nd nd nd

Table 3B. Elevations and percentage cover for Transect B–B′, Corkscrew marsh, South San Francisco Bay, CaliforniaContinued. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]
18 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 3.63 nd nd nd nd nd nd

2 3.86 2.55 0 0 50 0 50 0

3 4.84 2.34 0 0 0 0 100 0

4 16.58 2.33 0 0 0 0 100 0

5 28.47 2.37 0 0 40 0 60 0

6 34.38 2.33 0 0 0 0 100 0

7 34.77 2.22 0 0 0 0 100 0

8 35.68 2.30 0 0 0 0 100 0

9 41.15 2.36 0 0 0 0 100 0

10 44.75 2.26 0 0 0 0 100 0

11 45.56 1.24 nd nd nd nd nd nd

12 46.97 2.28 0 60 0 10 30 0

13 49.10 1.46 nd nd nd nd nd nd

14 49.83 1.09 nd nd nd nd nd nd

15 55.05 1.10 nd nd nd nd nd nd

16 56.87 1.43 50 0 0 0 0 50

17 58.74 2.15 20 0 0 0 0 80

18 60.34 2.30 0 100 0 0 0 5

19 63.99 2.31 0 85 0 15 0 0

20 68.65 2.36 0 80 10 10 0 0

21 72.44 2.44 0 80 0 20 0 0

22 74.28 2.27 0 90 0 10 0 10

23 77.80 2.31 0 90 10 0 0 0

24 78.54 1.48 40 0 0 0 0 60

25 79.01 1.53 40 0 0 0 0 60

26 79.63 2.30 0 100 0 0 0 10

27 81.53 2.35 0 80 0 20 0 Trace

28 87.49 2.34 0 80 0 20 0 5

29 94.20 2.39 0 60 0 20 20 0

30 99.53 2.30 0 50 10 40 0 0

31 100.11 2.16 0 50 10 40 0 0

32 101.04 1.13 nd nd nd nd nd nd

33 104.59 0.90 nd nd nd nd nd nd

34 105.31 1.19 40 0 0 0 0 60

35 105.67 2.18 0 60 0 40 0 0

36 108.80 2.30 0 40 0 20 40 0

37 110.82 2.30 0 50 0 50 0 0

38 111.11 2.08 20 0 0 0 0 80

39 113.65 2.01 0 0 0 0 0 100

40 115.21 1.06 nd nd nd nd nd nd

41 116.15 0.88 nd nd nd nd nd nd

42 116.92 0.82 nd nd nd nd nd nd

43 117.48 1.44 nd nd nd nd nd nd

44 117.72 2.21 0 50 Trace 50 0 0

45 125.06 2.30 0 100 0 0 0 10

46 131.05 2.33 0 90 0 0 10 0

47 135.51 2.42 0 50 0 20 30 0

48 138.39 2.45 0 80 0 20 0 0

49 139.02 1.96 20 0 0 0 0 80

50 140.63 1.52 0 0 0 0 0 100

Table 3C. Elevations and percentage cover for Transect C–C′, Corkscrew marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

18 
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

51 141.75 0.74 nd nd nd nd nd nd

52 143.92 0.87 nd nd nd nd nd nd

53 145.06 1.81 0 0 0 0 0 100

54 146.03 1.90 0 0 0 0 0 100

55 146.34 2.34 0 100 0 0 0 0

56 156.23 2.31 0 70 0 0 30 15

57 168.57 2.28 0 40 0 0 0 60

58 183.92 2.27 20 0 0 0 80 50

59 186.59 2.10 20 0 0 0 30 60

60 187.49 2.26 20 0 0 0 60 50

61 188.78 2.25 30 0 0 0 50 50

62 189.45 2.11 40 0 0 0 20 50

63 189.96 2.25 0 0 0 0 60 50

64 197.57 2.25 0 0 0 10 60 60

65 202.02 2.26 0 100 0 0 0 30

66 202.59 2.14 30 0 0 0 0 40

67 202.92 2.26 0 100 0 0 0 10

68 206.16 2.29 0 80 0 20 0 Trace

69 208.51 2.26 0 100 0 0 0 20

70 209.28 2.05 0 60 0 0 0 40

71 209.49 2.32 0 100 0 0 0 Trace

72 211.41 2.26 0 90 0 10 0 Trace

73 213.24 2.29 0 100 0 0 0 0

74 214.04 1.92 0 0 0 0 0 100

75 214.61 2.31 0 90 0 10 0 0

76 218.85 2.28 0 80 0 20 0 0

77 220.81 2.27 0 70 0 30 0 0

78 221.52 2.13 0 60 0 40 0 0

79 222.06 2.31 0 70 0 30 0 0

80 225.08 2.24 0 80 0 20 0 0

81 226.14 1.98 20 0 0 0 0 80

82 226.90 2.23 0 80 0 20 0 0

83 230.47 2.28 0 100 0 0 0 0

84 230.96 1.95 10 0 0 0 0 90

85 231.30 2.19 0 10 0 90 0 30

86 233.06 2.21 nd nd nd nd nd nd

87 234.83 2.05 0 0 0 0 100 50

88 235.88 1.61 10 0 0 0 20 90

89 236.97 0.98 nd nd nd nd nd nd

Table 3C. Elevations and percentage cover for Transect C–C′, Corkscrew marsh, South San Francisco Bay, California—Contined. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4505 and based on the National Tidal Datum Epoch (1960–78). Artiplex patula L., 

Deschampsia cespitosa L., Grindelia stricta DC., and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

CA-3339 Heading 1 19
20 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

1 0.00 0.79 nd nd nd nd nd nd nd nd nd

2 0.61 1.72 nd nd nd nd nd nd nd nd nd

3 2.44 1.67 nd nd nd nd nd nd nd nd nd

4 3.05 1.97 nd nd nd nd nd nd nd nd nd

5 6.71 1.92 0 0 95 0 0 0 0 5 Trace

6 8.53 2.03 nd nd nd nd nd nd nd nd nd

7 8.84 2.21 0 75 20 0 0 0 0 5 0

8 10.97 2.30 0 5 70 0 0 0 0 25 0

9 12.50 2.25 0 40 60 0 0 0 0 0 0

10 13.41 2.29 nd nd nd nd nd nd nd nd nd

11 16.15 2.24 0 0 100 0 0 0 0 0 0

12 26.21 1.91 0 0 75 0 0 0 0 5 20

13 43.89 1.98 0 0 90 0 0 0 0 10 0

14 48.46 1.83 0 0 40 0 0 0 0 40 20

15 49.07 1.82 nd nd nd nd nd nd nd nd nd

16 49.99 1.93 0 0 45 0 0 0 0 45 10

17 55.47 2.03 0 0 90 0 0 0 0 5 5

18 56.39 1.90 nd nd nd nd nd nd nd nd nd

19 57.30 2.02 0 5 40 0 0 20 0 35 5

20 74.37 2.05 0 0 0 0 0 30 0 60 10

21 78.64 2.01 5 35 0 0 0 0 0 45 15

22 78.94 1.95 nd nd nd nd nd nd nd nd nd

23 79.25 1.82 nd nd nd nd nd nd nd nd nd

24 80.16 2.05 5 50 0 0 0 0 0 30 15

25 92.05 1.98 5 25 0 0 0 0 0 30 40

26 92.96 1.58 0 0 0 0 0 0 0 5 95

27 93.57 1.43 0 0 0 0 0 0 0 0 100

28 94.18 1.28 0 0 0 0 0 0 0 0 100

29 94.79 1.02 15 0 0 0 0 0 0 Trace 85

30 96.01 1.17 90 0 0 0 0 0 0 0 10

31 97.54 2.02 0 0 95 0 0 0 0 0 5

32 104.85 2.10 0 0 85 0 0 10 0 Trace 5

33 120.09 2.06 0 0 0 0 0 55 0 30 15

34 131.06 2.01 0 5 0 0 0 60 0 20 15

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal bennchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
Table 4A 21

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

35 132.59 1.84 0 0 0 0 0 5 0 65 30

36 133.81 2.04 0 5 0 0 0 45 0 40 10

37 135.33 2.08 5 5 0 0 0 30 0 50 10

38 137.77 2.05 5 0 0 0 0 30 0 55 10

39 138.07 1.48 nd nd nd nd nd nd nd nd nd

40 138.38 1.23 nd nd nd nd nd nd nd nd nd

41 139.29 1.37 50 0 0 0 0 0 0 Trace 50

42 139.90 1.86 30 Trace 0 0 0 0 0 10 60

43 150.57 2.12 10 10 0 0 0 0 0 60 20

44 167.34 1.79 0 0 0 0 0 0 0 30 70

45 167.64 1.65 nd nd nd nd nd nd nd nd nd

46 169.47 1.08 nd nd nd nd nd nd nd nd nd

47 171.60 1.80 20 0 0 0 0 0 0 0 80

48 181.05 2.13 35 0 0 0 0 0 0 55 10

49 196.29 2.13 10 0 0 0 0 Trace 0 80 10

50 200.86 2.13 20 0 0 0 0 0 0 80 30

51 226.77 2.08 35 0 0 0 0 Trace 0 5 60

52 242.01 2.03 10 0 50 0 0 0 0 30 10

53 253.90 1.92 0 0 0 0 0 0 0 60 40

54 254.51 1.12 nd nd nd nd nd nd nd nd nd

55 255.12 1.15 80 0 0 0 0 0 0 0 20

56 256.34 1.96 0 0 10 0 0 0 0 30 60

57 257.25 2.05 0 0 45 0 0 0 0 40 15

58 272.49 2.10 0 0 85 0 0 0 0 5 10

59 287.73 2.12 10 5 5 0 0 0 0 60 20

60 294.44 2.08 0 0 0 0 0 0 0 50 50

61 297.18 1.90 0 0 0 0 0 0 0 65 35

62 301.14 2.03 10 0 0 0 0 0 0 40 50

63 301.45 1.87 nd nd nd nd nd nd nd nd nd

64 302.36 1.51 30 0 0 0 0 0 0 20 50

65 302.97 1.96 nd nd nd nd nd nd nd nd nd

66 318.21 2.15 5 20 0 0 0 15 0 15 45

67 333.45 2.11 0 20 0 0 0 Trace 0 40 40

68 346.25 1.44 nd nd nd nd nd nd nd nd nd

69 346.56 1.05 nd nd nd nd nd nd nd nd nd

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
22 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

70 347.17 0.94 nd nd nd nd nd nd nd nd nd

71 348.39 2.02 0 Trace 0 0 0 0 0 40 60

72 357.84 2.12 0 0 80 0 0 0 0 15 5

73 366.98 2.11 5 Trace 95 0 0 0 0 Trace 0

74 367.89 1.67 nd nd nd nd nd nd nd nd nd

75 368.20 1.30 nd nd nd nd nd nd nd nd nd

76 368.81 1.16 nd nd nd nd nd nd nd nd nd

77 369.42 1.58 nd nd nd nd nd nd nd nd nd

78 373.08 2.14 0 20 10 0 0 0 0 40 30

79 379.17 2.14 0 10 85 0 0 0 0 5 Trace

80 387.10 2.05 0 0 45 0 0 0 0 10 45

81 388.92 1.23 80 0 0 0 0 0 0 0 20

82 391.97 1.41 40 0 0 0 0 0 0 0 60

83 393.80 2.03 0 0 70 0 0 Trace 0 5 25

84 402.64 2.00 0 0 60 0 0 0 0 40 Trace

85 402.95 1.72 nd nd nd nd nd nd nd nd nd

86 403.56 1.53 40 0 0 0 0 0 0 0 60

87 404.77 1.95 0 10 0 0 0 0 0 40 50

88 410.87 2.02 10 5 0 0 0 0 0 45 40

89 412.39 1.85 nd nd nd nd nd nd nd nd nd

90 414.22 1.86 40 0 15 0 0 0 0 25 20

91 415.14 1.97 30 0 15 0 0 0 0 30 25

92 426.11 1.96 10 0 0 0 0 0 0 60 30

93 426.42 1.97 nd nd nd nd nd nd nd nd nd

94 427.02 1.74 30 0 0 0 0 0 0 35 35

95 427.63 1.86 nd nd nd nd nd nd nd nd nd

96 435.86 2.04 15 0 0 0 0 15 0 30 40

97 436.17 2.00 nd nd nd nd nd nd nd nd nd

98 436.47 1.94 20 0 0 0 0 0 0 25 55

99 437.39 2.07 0 60 0 0 0 Trace 0 0 40

100 440.13 2.12 0 20 15 0 0 0 0 25 40

101 459.33 2.06 0 0 40 0 0 0 0 5 60

102 460.25 1.87 0 0 30 0 0 0 0 0 70

103 460.86 1.24 nd nd nd nd nd nd nd nd nd

104 462.99 1.22 40 0 0 0 0 0 0 0 60

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
Table 4A 23

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

105 463.91 2.02 0 0 65 0 0 0 0 20 15

106 470.61 2.03 0 25 30 0 0 30 0 10 5

107 482.80 2.01 nd nd nd nd nd nd nd nd nd

108 483.11 1.97 10 0 0 0 0 0 0 0 90

109 485.24 1.41 40 0 0 0 0 0 0 0 60

110 486.16 1.69 50 0 0 0 0 0 0 0 50

111 501.09 2.11 0 0 40 0 0 35 0 25 0

112 505.36 2.06 0 0 10 0 0 65 0 15 10

113 505.97 2.06 nd nd nd nd nd nd nd nd nd

114 508.41 0.98 nd nd nd nd nd nd nd nd nd

115 511.45 1.05 nd nd nd nd nd nd nd nd nd

116 512.06 1.12 70 0 0 0 0 0 0 0 30

117 516.33 2.09 0 0 70 0 0 20 0 10 0

118 531.57 2.07 0 0 65 0 0 0 0 25 10

119 536.75 1.85 5 0 0 0 0 0 0 75 20

120 537.06 1.82 nd nd nd nd nd nd nd nd nd

121 538.28 1.65 50 0 0 0 0 0 0 0 50

122 539.50 2.00 nd nd nd nd nd nd nd nd nd

123 549.86 2.05 0 0 0 0 0 0 0 80 20

124 555.04 1.97 0 0 0 0 0 40 0 30 30

125 555.65 1.87 nd nd nd nd nd nd nd nd nd

126 558.39 1.83 20 0 25 0 0 0 0 25 30

127 559.00 2.04 0 0 50 0 0 0 0 25 25

128 562.05 2.07 0 0 95 0 0 0 0 5 0

129 575.77 2.05 0 0 60 0 0 30 0 10 0

130 576.38 1.29 60 0 0 0 0 0 0 0 40

131 577.60 1.32 30 0 0 0 0 0 0 0 70

132 578.21 1.60 10 0 0 0 0 0 0 0 90

133 592.53 2.10 0 0 0 0 0 0 0 40 60

134 602.89 2.00 0 0 0 0 0 0 0 85 60

135 603.20 1.37 80 0 0 0 0 0 0 0 20

136 604.42 1.26 50 0 0 0 0 0 0 0 50

137 605.03 1.96 0 0 0 0 0 10 0 50 40

138 608.38 1.98 10 10 25 0 0 0 0 25 30

139 613.56 1.93 0 0 65 0 0 0 0 20 15

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
24 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

140 613.87 1.72 25 0 0 0 0 0 0 15 60

141 614.48 1.82 0 0 0 0 0 30 0 55 15

142 614.78 1.95 nd nd nd nd nd nd nd nd nd

143 619.35 2.01 0 0 0 0 0 45 0 25 30

144 619.66 1.95 nd nd nd nd nd nd nd nd nd

145 620.27 1.77 nd nd nd nd nd nd nd nd nd

146 620.88 1.97 0 0 5 0 0 45 0 25 25

147 623.01 2.08 0 0 75 0 0 5 0 10 10

148 637.03 2.05 0 0 80 0 0 5 0 5 10

149 638.56 1.80 10 0 0 0 0 0 0 35 55

150 640.08 1.98 0 0 0 0 0 0 0 50 50

151 651.05 2.02 5 0 0 0 0 0 0 80 15

152 651.97 1.83 0 0 0 0 0 0 0 75 25

153 652.58 1.55 70 0 0 0 0 0 0 0 30

154 653.49 1.97 20 0 0 0 0 0 0 50 30

155 663.24 2.04 20 0 0 0 0 0 0 45 35

156 663.55 1.89 nd nd nd nd nd nd nd nd nd

157 663.85 1.75 40 0 0 0 0 0 0 0 60

158 664.46 1.98 20 0 0 0 0 0 0 40 40

159 671.78 2.13 0 Trace 0 0 0 45 0 55 5

160 680.92 2.13 0 Trace 0 0 0 45 0 45 10

161 684.28 1.35 45 0 0 0 0 0 0 5 50

162 685.50 0.98 70 0 0 0 0 0 0 0 30

163 687.02 1.15 40 0 0 0 0 0 0 0 60

164 688.24 1.88 20 0 0 0 0 0 0 50 30

165 699.21 2.10 0 0 0 0 0 0 0 40 60

166 714.45 2.07 5 0 0 0 0 0 0 65 30

167 730.30 2.06 0 0 0 0 0 0 0 70 30

168 730.91 1.51 30 0 0 0 0 0 0 0 70

169 732.13 0.91 nd nd nd nd nd nd nd nd nd

170 732.74 0.98 nd nd nd nd nd nd nd nd nd

171 734.57 1.87 30 0 0 0 0 0 0 0 70

172 744.93 2.11 0 0 90 0 0 0 0 0 10

173 757.43 2.06 0 Trace 5 0 0 55 0 15 25

174 758.65 1.90 0 80 0 0 0 0 0 10 10

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
Table 4A 25

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

175 758.95 1.87 nd nd nd nd nd nd nd nd nd

176 759.87 1.86 20 0 0 0 0 30 0 30 20

177 760.17 2.03 nd nd nd nd nd nd nd nd nd

178 769.92 1.91 0 0 0 0 0 0 0 70 30

179 770.53 1.90 60 0 0 0 0 0 0 0 40

180 770.84 1.63 nd nd nd nd nd nd nd nd nd

181 772.36 1.56 5 0 0 0 0 0 0 45 50

182 773.58 1.94 5 0 0 0 0 0 0 50 45

183 775.41 2.01 0 0 0 0 0 Trace 0 55 35

184 794.61 1.95 0 0 0 0 0 20 0 45 35

185 794.92 1.86 nd nd nd nd nd nd nd nd nd

186 797.05 1.66 80 0 0 0 0 0 0 0 20

187 798.58 1.91 15 0 0 0 0 0 0 55 30

188 805.89 2.21 0 0 0 0 0 50 0 30 20

189 811.68 2.12 20 0 0 0 0 0 0 50 30

190 812.29 1.52 40 0 0 0 0 0 0 0 60

191 812.60 1.48 40 0 0 0 0 0 0 0 60

192 813.21 1.81 0 0 0 0 0 40 0 10 50

193 818.08 2.24 60 0 0 0 0 25 0 15 Trace

194 827.23 1.37 40 0 0 0 0 0 0 0 60

195 827.84 1.38 25 0 0 0 0 0 0 0 75

196 829.36 1.82 5 0 15 0 0 0 0 0 80

197 829.97 1.98 0 0 25 0 0 0 0 0 75

198 833.32 2.23 0 0 100 0 0 0 0 Trace Trace

199 836.37 2.23 0 0 100 0 0 0 0 0 0

200 851.61 2.21 0 0 100 0 0 0 0 0 Trace

201 866.85 2.23 0 0 95 0 0 0 0 5 0

202 877.82 2.01 0 0 70 0 0 0 0 0 30

203 878.13 1.84 0 0 30 0 0 0 0 0 70

204 879.35 2.06 nd nd nd nd nd nd nd nd nd

205 879.96 2.19 0 0 50 0 0 0 0 30 20

206 888.19 2.21 0 0 0 0 0 20 0 40 40

207 897.33 2.18 0 0 0 0 0 45 0 5 50

208 899.46 2.08 0 0 0 0 0 25 0 15 60

209 899.77 2.03 nd nd nd nd nd nd nd nd nd

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
26 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

210 900.38 1.89 30 0 0 0 0 0 0 0 70

211 900.99 2.04 25 0 0 0 0 0 0 10 65

212 912.57 2.15 0 0 0 0 0 0 0 50 50

213 915.62 2.07 10 0 0 0 0 40 0 30 20

214 918.36 2.16 0 0 0 0 0 50 0 Trace 50

215 927.81 2.20 0 0 0 0 0 0 0 50 50

216 943.05 2.28 5 0 0 0 0 0 0 80 15

217 955.24 2.18 80 0 0 0 0 Trace 0 Trace 20

218 957.99 1.84 30 0 0 0 0 0 0 Trace 70

219 958.29 1.34 30 0 0 0 0 0 0 0 70

220 959.51 1.23 nd nd nd nd nd nd nd nd nd

221 959.82 2.12 30 0 0 0 0 30 0 40 0

222 975.06 2.21 0 0 0 0 0 0 0 95 5

223 976.58 2.12 0 0 0 0 0 0 0 90 10

224 976.88 2.03 nd nd nd nd nd nd nd nd nd

225 977.80 1.76 nd nd nd nd nd nd nd nd nd

226 978.10 1.98 20 0 0 0 0 40 0 10 30

227 988.77 2.18 5 0 0 0 0 0 0 50 45

228 995.48 2.08 0 0 0 0 0 0 0 60 40

229 996.70 2.05 nd nd nd nd nd nd nd nd nd

230 998.52 2.01 0 0 Trace 0 0 60 0 10 30

231 998.83 2.13 nd nd nd nd nd nd nd nd nd

232 1001.27 2.14 0 0 0 0 0 70 0 15 15

233 1001.88 1.95 nd nd nd nd nd nd nd nd nd

234 1002.79 1.98 nd nd nd nd nd nd nd nd nd

235 1003.10 2.19 0 0 0 0 0 0 0 40 60

236 1011.63 2.24 0 0 55 0 0 0 0 25 20

237 1019.25 2.27 0 0 50 0 0 50 0 Trace 0

238 1021.99 2.07 0 0 0 0 0 0 0 10 90

239 1022.30 1.96 5 0 0 0 0 0 0 5 90

240 1022.91 1.48 nd nd nd nd nd nd nd nd nd

241 1023.52 1.07 nd nd nd nd nd nd nd nd nd

242 1024.13 1.18 nd nd nd nd nd nd nd nd nd

243 1025.35 2.16 0 0 15 0 0 30 0 20 35

244 1034.49 2.23 0 0 0 0 0 65 0 30 5

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
Table 4A 27

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

245 1049.73 2.23 5 0 0 0 0 0 0 85 10

246 1063.75 2.20 0 0 0 0 0 75 0 20 5

247 1064.06 1.83 20 0 0 0 0 0 0 0 80

248 1066.19 1.34 60 0 0 0 0 0 0 0 40

249 1066.50 1.71 nd nd nd nd nd nd nd nd nd

250 1080.21 2.23 0 0 50 0 0 40 0 5 5

251 1095.45 2.23 0 0 95 0 0 0 0 5 Trace

252 1110.69 2.24 0 0 100 0 0 0 0 0 0

253 1122.88 2.25 0 0 0 0 0 65 0 30 5

254 1129.89 2.09 10 0 0 0 0 0 0 90 Trace

255 1130.50 1.16 nd nd nd nd nd nd nd nd nd

256 1131.42 1.19 nd nd nd nd nd nd nd nd nd

257 1132.03 1.86 nd nd nd nd nd nd nd nd nd

258 1141.17 2.23 0 0 70 0 0 30 0 Trace Trace

259 1156.41 2.26 0 0 90 0 0 0 0 5 5

260 1171.65 2.19 0 0 0 0 0 0 0 80 20

261 1172.26 2.17 nd nd nd nd nd nd nd nd nd

262 1172.57 2.04 nd nd nd nd nd nd nd nd nd

263 1178.05 2.06 nd nd nd nd nd nd nd nd nd

264 1178.36 2.17 0 0 0 0 0 0 0 90 10

265 1182.62 2.09 0 0 0 0 0 0 0 95 5

266 1182.93 2.08 nd nd nd nd nd nd nd nd nd

267 1186.28 2.03 nd nd nd nd nd nd nd nd nd

268 1186.59 2.22 0 0 0 0 0 0 0 100 Trace

269 1199.08 2.15 0 0 0 0 0 0 0 90 10

270 1199.69 1.95 nd nd nd nd nd nd nd nd nd

271 1200.30 1.95 nd nd nd nd nd nd nd nd nd

272 1200.61 2.11 10 0 0 0 0 0 0 50 40

273 1202.13 2.23 5 0 0 0 0 0 0 60 35

274 1205.79 2.12 0 0 0 0 0 0 0 65 35

275 1206.09 2.06 nd nd nd nd nd nd nd nd nd

276 1210.36 1.95 5 0 0 0 0 0 0 65 30

277 1211.28 2.14 nd nd nd nd nd nd nd nd nd

278 1217.07 1.92 10 0 0 0 0 0 0 50 40

279 1217.37 1.83 0 0 0 0 0 0 0 40 60

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
28 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

280 1217.98 2.03 10 0 0 0 0 0 0 50 40

281 1218.29 2.15 nd nd nd nd nd nd nd nd nd

282 1222.86 2.14 nd nd nd nd nd nd nd nd nd

283 1223.16 1.85 0 0 0 0 0 0 0 0 70

284 1223.47 1.83 nd nd nd nd nd nd nd nd nd

285 1224.38 2.15 0 0 5 0 0 80 0 10 5

286 1232.61 2.29 0 0 45 0 0 45 0 10 0

287 1244.80 2.30 0 0 95 0 0 50 0 5 0

288 1261.26 2.17 0 0 70 0 0 0 0 30 0

289 1261.87 1.26 nd nd nd nd nd nd nd nd nd

290 1263.70 1.41 30 0 0 0 0 0 0 0 70

291 1264.62 2.09 30 0 0 0 0 0 0 0 70

292 1265.22 2.14 25 0 0 0 0 0 0 0 75

293 1268.58 2.17 20 0 20 0 0 0 0 Trace 60

294 1269.19 2.30 0 0 100 0 0 0 0 Trace 0

295 1278.33 2.41 0 0 20 15 35 0 0 25 0

296 1289.18 2.52 0 0 10 60 10 0 10 10 0

297 1292.66 1.93 10 0 0 0 0 0 0 0 90

298 1292.96 1.87 10 0 0 0 0 0 0 0 90

299 1296.62 1.70 0 0 0 0 0 0 0 0 100

300 1299.67 1.51 nd nd nd nd nd nd nd nd nd

Table 4A. Elevations and percentage cover for Transect A–A′, Bird Island marsh, South San Francisco Bay, California—Continued.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
Station Distance along 

transect (meters)

Elevation

(meters)

1 6.10 2.12

2 10.36 1.96

3 15.54 1.88

4 18.29 1.78

5 18.59 0.82

Table 4B. Elevations and percentage cover for Transect 

B rt–B rt′, Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 

941-4483 and based on the National Tidal Datum Epoch (1960–78). No 

plant percentage cover data were collected for this transect]

Table 4B 29
30 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station Distance along 

transect (meters)

Elevation

(meters)

1 15.24 2.09

2 30.48 2.10

3 38.71 1.98

4 39.32 1.96

5 40.23 1.71

6 43.89 1.84

7 44.50 1.94

8 49.07 1.91

9 54.86 1.77

10 57.30 1.87

11 60.96 1.94

12 69.49 2.27

13 72.54 1.95

14 75.59 1.58

15 82.91 1.39

16 86.87 1.32

Table 4C. Elevations and percentage cover for Transect B lt–B lt′, 

Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 

941-4483 and based on the National Tidal Datum Epoch (1960–78). No 

plant percentage cover data were collected for this transect]
Station Distance along 

transect (meters)

Elevation

(meters)

1 8.23 2.01 2 8.53 1.51 3 9.14 1.63 4 9.45 1.80 5 11.28 1.96 6 12.80 1.89 7 13.72 1.54 8 14.63 1.57 9 14.94 1.81

10 15.85 1.85

11 16.15 1.73

12 17.07 1.82

13 17.98 2.02

14 19.20 2.05

15 21.03 1.78

16 21.95 1.66

17 22.56 2.00

18 30.48 2.07

19 39.62 2.12

20 48.77 2.08

21 60.96 2.10

22 70.10 2.09

23 79.25 2.09

24 89.31 2.01

25 89.92 1.66

26 90.53 1.98

27 90.83 2.03

28 91.44 2.06

29 100.58 2.14

30 109.73 2.14

31 121.92 2.15

32 131.06 2.23

33 141.43 2.04

34 141.73 1.27

Table 4D. Elevations and percentage cover for Transect C rt–C rt′

Rt, Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 

941-4483 and based on the National Tidal Datum Epoch (1960–78). No 

plant percentage cover data were collected for this transect]

Table 4D 31
32 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station Distance along 

transect (meters)

Elevation

(meters)

1 9.14 2.05

2 12.50 1.99

3 13.41 1.12

4 14.02 1.26

5 16.15 1.85

6 16.46 1.75

7 16.76 1.92

8 24.38 2.03

9 30.48 2.05

10 32.92 1.86

11 33.22 1.81

12 37.49 1.86

13 45.72 2.09

14 54.86 1.87

15 55.17 1.86

16 57.91 1.91

17 58.52 1.87

18 60.96 2.04

19 70.10 2.02

20 79.25 2.09

21 91.44 2.06

22 100.58 1.95

23 100.89 1.76

24 102.41 1.99

25 109.73 2.11

26 116.43 2.00

27 118.26 2.02

28 119.18 1.21

29 122.83 1.51

30 123.75 2.01

31 137.16 1.72

32 144.78 1.61

33 148.74 1.39

Table 4E. Elevations and percentage cover for Transect C lt–C lt′, Bird Island marsh, South San Francisco 

Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal 

benchmark 941-4483 and based on the National Tidal Datum 

Epoch (1960–78). No plant percentage cover data were 

collected for this transect]
Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

1 7.62 2.13 0 25 20 0 0 0 0 25 30

2 15.24 2.12 0 0 0 0 0 20 0 55 25

3 22.86 2.12 0 0 0 0 0 10 0 70 20

4 30.48 2.08 5 0 0 0 0 0 0 65 30

5 38.10 2.07 5 0 0 0 0 0 0 80 15

6 42.67 1.82 50 0 0 0 0 0 0 0 50

7 43.28 1.54 50 0 0 0 0 0 0 0 50

8 44.20 1.94 0 0 0 0 0 0 0 75 25

9 45.72 2.09 0 Trace 0 0 0 0 0 85 15

10 51.82 2.06 10 0 0 0 0 0 0 80 10

11 53.04 1.87 80 0 0 0 0 0 0 0 20

12 53.95 2.02 5 0 0 0 0 0 0 70 25

13 58.83 2.03 5 0 0 0 0 0 0 65 30

14 59.74 1.90 nd nd nd nd nd nd nd nd nd

15 60.35 2.04 10 0 0 0 0 0 0 60 30

16 67.97 2.12 5 0 0 0 0 0 0 85 10

17 75.59 2.11 15 0 0 0 0 0 0 15 70

18 76.81 2.07 70 0 0 0 0 0 0 Trace 30

19 80.16 2.11 50 0 0 0 0 0 0 25 25

20 87.48 2.16 15 0 0 0 0 0 0 55 30

21 95.10 2.18 20 10 0 0 0 0 0 30 40

22 102.11 2.15 0 0 65 0 0 0 0 25 10

23 105.46 1.78 nd nd nd nd nd nd nd nd nd

24 105.77 0.78 nd nd nd nd nd nd nd nd nd

Table 4F. Elevations and percentage cover for Transect D rt–D rt′, Bird Island marsh, South San Francisco Bay, California.

Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]

Table 4F 33
34 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance 

along 

transect 

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Deschampsia 

cespitosa

L.

(percent)

Distichlis

spicata L. 

(percent)

Frankenia

salina

Molina

(percent)

Grindelia

stricta

DC. 

(percent)

Jaumea

carnosa

Less. 

(percent)

Limonium

californicum

Boiss.

 (percent)

Salicornia 

virginica

 L. 

(percent)

Spartina

foliosa

 Trin. 

(percent)

1 9.14 1.86 10 0 0 0 0 20 0 0 70

2 10.36 1.05 30 0 0 0 0 0 0 0 70

3 10.97 1.14 nd nd nd nd nd nd nd nd nd

4 11.28 1.94 0 0 0 0 0 20 0 70 10

5 19.20 2.13 0 0 65 0 0 10 0 10 15

6 27.13 2.11 0 0 50 0 0 30 0 20 0

7 35.05 2.12 0 0 0 0 0 40 0 20 40

8 45.11 2.11 0 0 40 0 0 0 0 40 20

9 51.82 2.08 15 0 0 0 0 0 0 25 60

10 59.44 1.81 20 0 0 0 0 0 0 60 20

11 65.84 1.03 nd nd nd nd nd nd nd nd nd

12 70.41 1.01 nd nd nd nd nd nd nd nd nd

13 72.85 1.77 0 0 0 0 0 25 0 20 55

14 77.11 2.04 0 0 0 0 0 40 0 45 15

15 81.99 2.05 10 0 0 0 0 0 0 60 30

16 88.39 2.10 nd nd nd nd nd nd nd nd nd

17 95.40 2.09 10 0 0 0 0 0 0 50 40

18 102.72 2.08 5 0 0 0 0 0 0 70 25

19 107.29 2.02 5 0 0 0 0 0 0 65 30

20 107.90 1.89 nd nd nd nd nd nd nd nd nd

21 114.30 2.12 5 0 0 0 0 0 0 55 40

22 121.31 2.10 5 0 0 0 0 0 0 65 30

23 129.24 2.06 10 0 30 0 0 0 0 40 20

24 136.25 2.11 0 0 50 0 0 0 0 40 10

25 143.26 2.10 0 0 30 0 0 0 0 55 15

26 149.96 2.08 5 0 10 0 0 0 0 45 40

27 156.67 2.07 5 0 0 0 0 0 0 40 60

28 163.68 1.88 nd nd nd nd nd nd nd nd nd

29 167.03 1.02 nd nd nd nd nd nd nd nd nd

30 169.16 2.09 nd nd nd nd nd nd nd nd nd

31 175.87 1.87 nd nd nd nd nd nd nd nd nd

32 181.97 1.73 0 0 0 0 0 0 0 0 100

33 192.33 1.25 0 0 0 0 0 0 0 0 100

Table 4G. Elevations and percentage cover for Transect D lt–D lt′, Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4483 and 941-4486 and based on the National Tidal Datum Epoch (1960–78). 

Atriplex patula L. not observed at this site; Trace, < 5 percent cover; nd, no data]
Station Distance along 

transect (meters)

Elevation

(meters)

1 9.75 2.07 2 10.36 1.28 3 12.50 2.12 4 16.76 2.15 5 21.64 2.12 6 21.95 1.98 7 24.38 2.02 8 25.30 2.08 9 30.48 2.22

10 38.10 2.25

11 46.94 1.59

12 47.24 1.51

13 48.16 2.00

14 48.77 2.13

15 54.86 2.25

16 60.96 2.22

17 62.79 2.22

18 63.09 2.21

19 69.19 1.68

20 69.80 1.72

21 73.15 2.22

22 76.20 2.10

23 76.81 1.82

24 77.42 1.93

25 78.03 2.20

26 85.34 2.26

27 91.44 2.26

28 94.18 2.11

29 95.71 2.11

30 96.01 2.04

31 96.32 1.98

32 96.93 2.16

33 101.50 2.13

34 101.80 2.11

35 102.41 2.10

36 103.02 2.22

37 109.73 2.28

38 117.04 2.19

39 121.92 2.27

40 124.66 2.21

41 124.97 1.56

Table 4H. Elevations and percentage cover for Transect E rt–E rt′

Rt, Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 

941-4483 and based on the National Tidal Datum Epoch (1960–78). No 

plant percentage cover data were collected for this transect]

Table 4H 35
Station Distance along 

transect (meters)

Elevation

(meters)

1 9.14 2.29

2 18.29 2.30

3 30.48 2.24

4 39.62 2.27

5 46.02 2.16

6 47.85 2.06

7 48.16 1.65

8 49.99 1.11

9 50.29 2.15

10 60.96 2.25

11 70.10 2.26

12 79.25 2.27

13 91.44 2.21

14 101.80 2.14

15 102.41 2.04

16 103.02 2.09

17 103.63 1.98

18 105.16 2.09

19 105.46 2.05

20 106.98 1.97

21 115.82 1.92

22 121.92 1.88

23 132.59 1.61

24 141.73 1.50

Table 4I. Elevations and percentage cover for Transect E lt–E lt′, 

Bird Island marsh, South San Francisco Bay, California.

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 

941-4483 and based on the National Tidal Datum Epoch (1960–78). No 

plant percentage cover data were collected for this transect]

36 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less.

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 2.52 60 0 0 0 0 0 0 40

2 6.10 2.48 25 0 0 0 0 0 75 40

3 12.19 2.50 0 0 0 0 0 0 100 0

4 18.29 2.48 0 0 0 0 0 0 100 10

5 24.38 2.40 0 0 0 0 0 0 20 50

6 30.48 2.47 0 0 0 0 0 0 100 Trace

7 36.58 2.51 0 0 0 0 0 0 100 0

8 42.67 2.46 0 0 0 0 0 0 100 0

9 48.77 2.47 0 0 0 0 0 0 100 Trace

10 54.86 2.47 0 0 0 0 25 0 75 0

11 60.96 2.45 0 0 0 0 75 0 30 0

12 64.31 2.42 nd nd nd nd nd nd nd nd

13 64.92 1.48 nd nd nd nd nd nd nd nd

14 65.84 2.37 nd nd nd nd nd nd nd nd

15 67.06 2.45 0 0 0 0 0 0 10 40

16 73.15 2.51 0 0 0 0 0 0 20 90

17 79.25 2.43 0 0 0 0 0 0 85 25

18 85.34 2.48 0 0 0 0 0 0 20 90

19 91.44 2.47 0 0 0 0 0 5 10 95

20 97.54 2.55 10 0 80 0 0 0 5 15

21 103.63 2.56 5 0 95 10 0 Trace Trace 0

22 109.73 2.68 0 0 90 0 0 0 0 Trace

23 115.82 2.61 0 0 85 0 0 15 0 35

24 121.92 2.64 25 0 0 0 10 0 75 10

25 128.02 2.34 0 0 0 0 0 0 0 100

26 134.11 1.87 0 0 0 0 0 0 0 80

27 138.99 1.45 0 0 0 0 0 0 0 100

Table 5A. Elevations and percentage cover for Transect 2N–2N′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

Table 5A 37
38 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 6.10 2.54 0 0 0 0 0 0 90 10

2 12.19 2.46 0 0 0 0 0 0 100 10

3 18.29 2.45 0 0 0 0 0 0 90 25

4 24.38 2.51 0 0 0 0 0 0 100 Trace

5 30.48 2.49 0 0 0 0 0 0 100 0

6 36.58 2.49 0 0 0 0 0 0 100 0

7 42.67 2.50 0 0 0 0 0 0 100 0

8 48.77 2.45 0 0 0 0 0 0 100 0

9 54.86 2.48 0 0 0 0 0 0 100 0

10 60.96 2.49 0 0 0 0 0 0 100 0

11 67.06 2.50 0 0 0 0 0 0 50 50

12 73.15 2.43 0 0 0 0 0 50 0 50

13 79.25 2.48 0 0 0 0 0 0 50 60

14 85.34 2.49 0 0 0 0 0 0 40 70

15 91.44 2.45 0 0 0 0 0 0 20 100

Table 5B. Elevations and percentage cover for Transect 2N rt–2N rt′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 6.10 2.50 0 0 0 0 0 0 100 Trace

2 12.19 2.50 0 0 0 0 0 0 100 0

3 18.29 2.47 0 Trace 0 0 0 0 90 10

4 24.38 2.48 0 0 0 0 0 0 90 20

5 30.48 2.48 0 0 0 0 0 0 100 0

6 36.58 2.53 0 0 0 0 0 0 100 0

7 42.67 2.48 0 0 0 0 0 0 100 0

8 48.77 2.47 0 0 0 0 0 0 100 0

9 54.86 2.53 0 0 0 0 0 0 100 0

10 60.96 2.50 10 10 0 0 0 0 80 0

11 67.06 2.37 0 0 0 0 0 0 50 50

12 73.15 2.46 0 0 0 0 0 20 50 80

13 79.25 2.42 0 0 0 0 0 0 40 70

14 85.34 2.44 0 0 0 0 0 30 20 60

15 91.44 2.53 0 0 0 0 10 0 30 90

Table 5C. Elevations and percentage cover for Transect 2N lt–2N lt′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]

Table 5C 39
40 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 2.52 nd nd nd nd nd nd nd nd

2 6.10 2.51 20 0 0 0 0 0 10 80

3 12.19 2.57 0 0 0 0 0 0 100 40

4 18.29 2.53 0 0 0 0 0 0 100 0

5 24.38 2.51 0 0 0 0 0 0 100 0

6 30.48 2.52 0 0 0 0 0 0 100 0

7 36.58 2.52 0 0 0 0 0 0 100 0

8 42.67 2.53 0 0 0 0 0 0 100 0

9 48.77 2.55 0 0 0 0 0 0 100 0

10 54.86 2.50 0 0 0 0 0 0 100 Trace

11 60.96 2.53 0 0 0 0 0 0 100 Trace

12 67.06 2.55 0 0 0 0 0 0 100 0

13 73.15 2.58 0 0 0 0 0 0 100 0

14 79.25 2.56 0 0 0 0 0 0 100 0

15 85.34 2.64 0 0 0 0 0 0 100 0

16 91.44 2.68 0 10 0 40 0 0 50 0

17 97.54 2.74 0 0 0 100 0 0 0 0

18 103.63 2.65 0 0 0 Trace 0 0 100 0

19 109.73 2.61 0 0 0 0 0 0 100 0

20 115.82 2.58 0 0 0 0 0 0 100 0

21 121.92 2.52 10 0 0 0 0 0 90 0

22 124.97 2.94 0 0 0 0 100 0 0 0

Table 5D. Elevations and percentage cover for Transect 2S–2S′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 2.45 0 0 0 0 0 0 90 5

2 6.10 2.53 0 0 0 0 0 0 25 70

3 12.19 2.54 0 0 0 0 0 0 100 10

4 18.29 2.54 0 0 0 0 0 0 100 0

5 24.38 2.52 0 0 0 0 0 0 100 0

6 30.48 2.52 0 0 0 0 0 0 100 0

Table 5E. Elevations and percentage cover for Transect 2S rt–2S rt′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover]

Table 5E 41
42 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 2.45 0 0 0 0 0 0 90 5

2 6.10 2.53 0 0 0 0 0 0 30 70

3 12.19 2.54 0 0 0 0 0 0 60 30

4 18.29 2.54 0 0 0 0 0 0 100 Trace

5 24.38 2.52 0 0 0 0 0 0 100 0

6 30.48 2.52 0 0 0 0 0 0 100 0

Table 5F Elevations and percentage cover for Transect 2S lt–2S lt′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover]
Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 2.44 0 0 85 0 0 15 0 10

2 3.05 2.47 0 0 80 0 0 10 10 40

3 6.10 2.44 0 0 0 0 0 80 20 40

4 9.14 2.47 0 0 0 0 0 95 5 40

5 12.19 2.48 0 0 5 0 0 80 15 30

6 15.24 2.49 75 0 10 0 10 Trace 15 50

7 18.29 2.52 20 0 80 0 0 Trace 0 25

8 21.34 2.53 0 0 90 0 0 Trace 10 10

9 24.38 2.49 0 0 0 0 50 0 15 20

10 27.43 2.53 0 0 0 0 0 25 60 40

11 30.48 2.53 0 0 65 0 0 15 20 20

Table 5G. Elevations and percentage cover for Transect 2A–2A′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover]

Table 5G 43
44 Tidal Marsh Vegetation and Elevation Surveys—Corkscrew Marsh, Bird Island, and Palo Alto Baylands, Calif., 1983

Station

Distance

along

transect

(meters)

Elevation 

(meters)

Bare

ground

(percent)

Atriplex

patula L. 

(percent)

Distichlis

spicata L.

(percent)

Frankenia

salina 

Molina

(percent)

Grindelia

stricta DC.

(percent)

Jaumea

carnosa

Less. 

(percent)

Salicornia

virginica L.

(percent)

Spartina

foliosa

Trin.

(percent)

1 0.00 2.52 10 0 Trace 80 0 10 0 20

2 3.05 2.53 0 0 50 50 0 0 0 10

3 6.10 2.51 10 20 70 5 10 10 5 30

4 9.14 2.54 0 0 Trace 50 0 50 0 15

5 12.19 2.48 5 0 0 25 0 60 10 60

6 15.24 2.51 10 0 25 25 0 40 0 50

7 18.29 2.51 15 0 55 15 0 0 15 70

8 21.34 2.50 10 0 70 20 0 0 0 30

9 24.38 2.52 50 0 10 0 0 35 5 90

10 27.43 2.51 35 0 45 0 0 10 10 80

11 30.48 2.50 0 0 60 0 0 30 10 10

12 33.53 2.57 0 0 80 0 0 15 5 5

13 36.58 2.54 0 0 0 0 0 85 15 50

14 39.62 2.51 75 0 0 0 0 15 10 80

15 42.67 2.52 45 0 30 0 0 25 0 70

16 45.72 2.52 70 0 0 0 0 Trace 30 90

Table 5H. Elevations and percentage cover for Transect 2B–2B′, Palo Alto Baylands marsh, South San Francisco Bay, California. 

[Vertical datum is Mean Lower Low Water (MLLW) for tidal benchmark 941-4525 and based on the National Tidal Datum Epoch (1960–78). Deschampsia 

cespitosa L. and Limonium californicum Boiss not observed at this site; Trace, < 5 percent cover; nd, no data]
Corkscrew

marsh

observations/

number of 

stations

Corkscrew 

marsh 

elevation 

range

(meters)

Corkscrew

marsh

median

elevation

(meters)

Bird Island 

observations/

number of 

stations

Bird Island 

elevation

range

(meters)

Bird Island 

median

elevation

(meters)

Palo Alto

Baylands

observations/

number of 

stations

Palo Alto 

Baylands 

elevation 

range (meters)

Palo Alto 

Baylands 

median 

elevation 

(meters)

All sites

observations/

number of 

stations

All sites 

elevation

range (meters)

All sites 

median 

elevation

(meters)

Bare Ground 57/266 1.19 to 2.47 2.01 128/268 0.98 to 2.28 1.96 21/114 2.48 to 2.64 2.51 206/648 0.98 to 2.64 2.02Atriplex patula L. 0/266 NA NA 0/268 NA NA 4/114 2.47 to 2.68 2.51 4/648 2.47 to 2.68 2.51

Deschampsia cespitosa

L.

0/266 NA NA 32/268 1.86 to 2.30 2.08 0/114 NA NA 32/648 1.86 to 2.30 2.08

Distichlis spicata L. 124/266 1.76 to 2.45 2.25 82/268 1.82 to 2.52 2.10 23/114 2.44 to 2.68 2.52 229/648 1.76 to 2.68 2.26Frankenia salina 

Molina

9/266 2.16 to 2.55 2.31 2/268 2.41 to 2.52 2.46 12/114 2.48 to 2.74 2.52 23/648 2.16 to 2.74 2.51

Grindelia stricta DC. 0/266 NA NA 2/268 2.41 to 2.52 2.46 8/114 2.45 to 2.94 2.50 10/648 2.41 to 2.94 2.50Jaumea carnosa Less. 57/266 2.06 to 2.45 2.30 66/268 1.77 to 2.30 2.08 29/114 2.43 to 2.61 2.51 152/648 1.77 to 2.61 2.24Limonium californicum

Boiss.

0/266 NA NA 1/268 NA NA 0/114 NA NA 1/648 none 2.52

Salicornia virginica L. 138/266 1.61 to 2.55 2.25 206/268 1.02 to 2.52 2.07 97/114 2.37 to 2.68 2.51 441/648 1.02 to 2.68 2.21Spartina foliosa Trin. 175/266 1.19 to 2.38 2.22 246/268 .98 to 2.28 2.03 73/114 1.45 to 2.68 2.50 494/648 0.98 to 2.68 2.12

Table 6. Total number of observations, observed range in elevation above MLLW, and median elevation for each plant species, South San Francisco Bay, California. [MLLW, Mean Lower Low Water; NA, not applicable]

Table 6 45