Palo Alto Baylands

Google Map Coordinates: X, Y

San Francisquito Creek is the last South Bay creek running above ground as it flows to the Bay.  As a result of its inclusion in the Palo Alto Baylands Nature Preserve, the wetland habitat at its mouth remains a refuge for many native species, including shorebirds and fish like the steelhead trout. The Baylands Preserve covers 1,940 acres and is the largest undisturbed marshland on the Bay.

 Shorebirds from all over the South Bay take advantage of the abundant resources in the natural marshes and nearby industrial salt ponds. To ensure the conservation of these birds and other wildlife, Save The Bay and the City of Palo Alto Baylands Nature Preserve are working together to restore wetland habitat at the mouth of San Francisquito Creek.

Glossary of Terms

  • Abiotic

    The non-living components of an ecosystem (ie. Light, soil, water, air)

  • Acidic

    Any substance that has the pH level below 7, or that has more free hydrogen ions (H+) than Hydroxide ions (OH-). Common acids are substances like lemon juice, vinegar, and battery acid.

  • Adaptation

    a change in the structure or behavior of a species over time in response to a change in its environment.

  • Algae

    simple, aquatic plants without roots, stems, or leaves, but with chlorophyll.

  • Anadromous:

    an animal that is born in fresh water, spends most of its adult life in salt water, and migrates back to fresh water to spawn.

  • Aquifer:

    an underground lake or pond containing fresh water.

  • Base:

    bases, or alkaline substances, are characterized by their bitter taste, slippery feel, and pH level above 7. Soap and baking soda are examples of bases.

  • Bay fill:

    the process of dumping soil, garbage, and other materials into the Bay and wetlands in order to change them into dry land on which to build.

  • Benthic organisms:

    species that live in the substrate (mud, sand, etc.) on the bottom of lakes, ponds, oceans, and tidal zones.

  • Bioaccumulation:

    the process by which certain substances (usually pollutants) accumulate in higher and higher concentrations within living organisms as they make their way up the food chain.

  • Biodiversity:

    the number of different species of living things in an area. The more variety among the different living things, the higher the diversity.

  • Biome:

    a major regional or global biotic community, such as a grassland or desert, characterized chiefly by the dominant forms of plant life and the prevailing climate.

  • Biotic:

    the living components in a habitat, (ie. plants, vertebrates, invertebrates, etc).

  • Brackish water:

    containing a mix of fresh and salt water.

  • Catadromous fish:

    an animal that is born in the salt water, spends most of its adult life in fresh water, and migrates back to salt water to spawn. Opposite of anadromous.

  • Consumer:

    organisms that cannot make their own food and are dependent on other living organisms (ie. plants or animals) as a source of energy.

  • Decomposer:

    an organism (ie. bacteria) that breaks down dead plants and animals into more basic elements, releasing nutrients.

  • Detritus:

    decomposing plant and animal matter.

  • Dike:

    a low wall, made of dirt, used to separate sections of a body of water from the main body; dikes are often used to make salt ponds, golf courses, airport, shoreside parks, and housing.

  • Dissolved oxygen:

    the amount of oxygen in the water, measured in parts per mission, or ppm. Although most fish can survive low levels of dissolved oxygen for short periods of time, most fish need at least 5 ppm. to be healthy and grow.

  • Dredging:

    the removal of sediments from the estuary floor (or other body of water).

  • Drainage:

    1) a watershed, or 2) the ability of a substance to pass water through it. Gravel has good drainage while clay has poor drainage.

  • Ebb tide:

    the return of tide water toward the ocean; the outgoing tide.

  • Ecology:

    the study of the interrelationships of and their environments.

  • Ecosystem:

    the plants an animals living in an area together with their surroundings, considered as a system of relationships.

  • Endemic:

    native to a specific region and found only in that one area (ie. endemic plants and animals).

  • Erosion:

    the process by which land surfaces are worn away by the movement of water, wind, waves, etc.

  • Estuary:

    a semi-enclosed body of water where fresh and salt water meet and mix.

  • Exoskeleton:

    a hard outer structure, such as the shell of an insect or crustacean, that provides protection or support for an organism.

  • Expiration:

    the act of breathing out; exhalation; often refers to plants releasing oxygen.

  • Extinction:

    the wiping out of an entire species of plant or animal.

  • Food web:

    an assemblage of organisms in an ecosystem, including plants, herbivores and carnivores, showing the relationship of “who eats who.”

  • Flood tide:

    the return of water toward the land; the incoming tide.

  • Groundwater:

    water that has percolated through the land’s surface and residues in aquifer’s or underground waterways.

  • Habitat:

    the native environment of an animal or plant; a habitat must include food, water, shelter, and space.

  • Halophyte:

    a plant adapted to living in a saline environment.

  • Hydrophyte:

    a plant adapted to living in wet conditions.

  • Invasive species:

    a species that invades or encroaches upon a habitat, outcompeting native species.

  • Levee:

    a low wall, made of dirt, used to separate sections of a body of water from the main body; levees are often used to make salt ponds, airports, shoreside parks, and housing.

  • Limiting factor:

    any environmental factor (food, pollution, etc.) whose presence or absence prevents the growth of a plant or animal population.

  • Marsh:

    an area of soft, wet, low-lying land, characterized by grassy vegetation; a transition zone between water and land.

  • Migration:

    when animals (ie. birds, fish, butterflies, or whales) instinctively travel from one place to another often over great distances, to mate or reach feeding grounds.

  • Mitigation:

    improving one area in order to compensate for the damaging of another.

  • Native species:

    any plant or animal that originated within a particular ecosystem; indigenous.

  • Niche:

    the particular set of environmental conditions that a specific species has evolved to inhabit most successfully.

  • Non-native species:

    any plant or animal species that was introduced to an ecosystem by humans; one that did not inhabit the ecosystem historically.

  • Non-point source pollution:

    widespread overland runoff containing pollutants; the contamination does not originate from one specific location, and pollution discharges over a wide land area.

  • Nutrient:

    any substance which provides energy for growth (such as food, vitamins, minerals). When materials decompose, their nutrients are released.

  • Pacific flyway:

    routes followed by birds migrating along the West coast between South America and Alaska.

  • pH scale:

    The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is basic. Each whole pH value below 7 is ten times more acidic than the next higher value.

  • Phosphates:

    nutrients found naturally in soil and water. Plants and animals need phosphates to grow. Phosphates are found in fertilizers, human and animal waste and some soaps.

  • Photosynthesis:

    the process by which green plants use the sun’s energy to produce glucose (food) from carbon dioxide and water; the by-product of this process is oxygen.

  • Phytoplankton:

    single-celled plant-like organisms that drift in the water current.

  • Plankton:

    organisms that drift in the water current (ie. animal and plant-like organisms; often small).

  • Point Source Pollution:

    pollutants discharged from any identifiable point, including pipes, ditches, channels, sewers, tunnels, and containers of various types.

  • Pollutants:

    anything that lessens or spoils the quality of water, air, or land that it touches.

  • Producers:

    an organism with chlorophyll which uses light energy (photosynthesis) and nutrients to make its own food; the first level in food chains; plants are producers

  • Restoration:

    the return of a functioning

  • Run-off:

    water that flows over or through the land in a watershed.

  • Salinity:

    the saltiness of the water, measured in parts per thousand, or ppt. For example, fresh water is 0 ppt and the water in the ocean is 35 ppt. The water in the Bay is a mix of fresh and ocean water, with varying salinity.

  • Scientific method:

    a series of steps (including observation, question, hypothesis, experimentation, results analysis, and conclusion) that can be used to logically solve problems.

  • Sediment:

    dirt, salt, or sand that flows off the land and settles to the bottom of a waterway or is suspended in the water.

  • Spawn:

    method of reproduction used by fish in which the female lays eggs and the male fertilizes them.

  • Slough:

    a slow moving meandering channel through a marsh; sloughs have muddy banks and are created by tides; natural irrigation channels or waterways.

  • Stewardship:

    behavior that exhibits a long-term commitment and sense of personal responsibility; one method involves volunteering for projects in the community.

  • Tides:

    the “rising and falling” of the ocean due to the gravitational pull of the moon and the sun on the earth.

  • Trophic level:

    a group of organisms that occupy the same position in a food chain.

  • Turbidity:

    a measure of how much sediment, plankton, or other organic matter is suspended in the water.

  • Watershed:

    the area of land that drains into a river and its tributaries; the area of land from which rain or melting snow drain into a river, stream, or other body of water.

  • Wetland:

    transitional areas between land and water. Three physical features characterize wetlands: standing water, saturated soils, and hydrophytic (water-loving) plants.

  • Zooplankton:

    animals that drift in the water current; often small.

Photos from the Field

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Our Partners

Site Observation Wall:

Soil characteristics verried dramatically at the transects on this location. There was step elevation between the marsh sea level and the trail level. The salinity jumped from transect 1 to transect 2, then was constant throughout. The pH was constant throughout our transects. We had lots of fun :-)

This graph illustrates the relationship between plant growth and soil moisture.


% Cover refers to the amount of ground covered by living plant material. A high number means that most of the quadrat was full of vegetation. A low % cover means that most of the quadrat was bare ground. Values are means ± SD.


The shading reflects variability around the line which shows the average relationship between the two variables. The line reflects a statistically significant relationship.


Each point is a mean value for 4 samples at each elevation, going from low (near the water) to high in the marsh. The range shown as a vertical bar around each mean is one standard deviation (SD) above and below the mean. Within this range is 68% of the data. A large number for SD indicates high variance.


Samples were split into exotics and natives and Simpson’s Diversity Indices were computed based on those two sets for the two habitats.


This graph illustrates the prevalence of natives vs. invasives in unrestored and restored areas.


Low elevation quadrats were next to the water, whereas high elevation quadrats were upland sites.
Each point is a mean value based on four samples at each of four elevation points on a transect. The error bars are standard deviations, indicating the variation. High values indicate high level of unpredictability from one sample to the next, as for elevation 4 of the restored habitat and elevation 3 of the unrestored marsh. The variation is due to natural variation.


This chart illustrates the mean number of certain plant species we found in unrestored areas. Quadrat 1 was closest to the water, while 4 was highest.


This chart illustrates the prevalence of invasive and native species in various zones.