Words that are used in definitions that are also defined in this glossary are italicized.


accretion: The act of adding material, such as an accretion of earth. 

algae: Simple rootless plants that grow in bodies of water (e.g.  estuaries) at rates dependent on the amounts of plant nutrients (e.g.  nitrogen and phosphorus) available in water. 

amphibian: A cold-blooded, smooth-skinned vertebrate animal of the class Amphibia, such as a frog or salamander, that typically hatches as an aquatic larva with gills.  The larva then transforms into an adult having air-breathing lungs. 

alluvial: Relating to the deposits made by flowing water; washed away from one place and deposited in another; as, alluvial soil, mud, accumulations, deposits. 

anaerobic: Not containing oxygen or not requiring oxygen.

aquifer: Underground rock or soil layer yielding groundwater for wells and springs, etc. 

bathymetry: Of or relating to measurements of the depths of water bodies, such as oceans or lakes. 

baylands: Baylands consist of shallow water habitats around the Bay.  They include lands that are touched by tides and lands that would be tidal in the absence of man-made structures.

berms: A mound or bank of earth, used especially as a barrier.

biota: The combined flora and fauna of a region.

bittern: Waste materials left over after common salt (sodium chloride) was harvested from the salt ponds.  Shown in laboratory studies to have toxic effects on aquatic life. 

bog: A wetland that has poorly-drained, acidic peat soil dominated by sedges and sphagnum moss. 

brackish: A mixture of fresh and saltwater typically found in estuarine areas. 

brines: Water containing large amounts of a salt or salts, especially sodium chloride.

buffer zone: A barrier between sensitive wildlife habitat and land uses such as agriculture or urban development.  A transitional zone intended to provide for compatibility of nearby dissimilar uses.

Candidate Species (Federal Definition): A species for which the U.S. Fish and Wildlife Service has on file sufficient information to support a proposal to list the species as endangered or threatened, but for which proposed rules have not yet been issued.

Candidate Species (State Definition): A native species or subspecies of a bird, mammal, fish, amphibian, reptile, or plant that the California Fish and Game Commission has formally noticed as being under review by the California Department of Fish and Game for addition to either the list of endangered species or the list of threatened species, or a species for which the Commission has published a notice of proposed regulation to add the species to either list. 

deep-water habitat: Aquatic habitats, such as in lakes, rivers and oceans, where surface water is permanent and deeper than 6.6 feet (2 meters) most of the year.

delta: A low triangular area where a river divides before entering a larger body of water.

desalination: The removal of salt (especially from sea water).

diversity: An ecological measure of the variety of organisms present in a habitat.

ecology: The study of the interactions between living things and their environment.

ecosystem: A basic functional unit of nature comprising both organisms and their nonliving environment, intimately linked by a variety of biological, chemical, and physical processes

Endangered (Federal definition): Any species which is in danger of extinction throughout all or a significant portion of its range.

Endangered (State definition): A native species or subspecies of a bird, mammal, fish, amphibian, reptile, or plant which is in serious danger of becoming extinct throughout all, or a significant portion, of its range due to one or more causes, including loss of habitat, change in habitat, overexploitation, predation, competition, or disease.

estuarine: Of, relating to, or found in an estuary.

estuary: The wide part of a river where it nears the sea; where fresh and salt water mix in a semi-enclosed body of water. 

eutrophication: Having waters rich in mineral and organic nutrients that promote a proliferation of plant life, especially algae, which reduces the dissolved oxygen content and often causes the extinction of other organisms.  Used to describe conditions of a lake or pond.

exotic species: Any introduced plant or animal species that is not native to the area and that may be considered a nuisance (e.g.  Norway Rat, Spartina, etc.).  See also invasive species.

fauna: Animals, especially the animals of a particular region or period, considered as a group.

flora: Plants considered as a group, especially the plants of a particular country, region, or time. 

floodplain: An area adjacent to a lake, stream, ocean or other body of water lying outside the ordinary banks of the water body and periodically filled by flood flows.  Often referred to as the area likely to be filled by the 100-year flood

geomorphic: Pertaining to the shape or surface of the earth, including small-scale changes in land surface resulting from restoration projects.

geotechnical: A science that deals with the application of geology to engineering. 

groundwater: Water that penetrates the earth's surface from precipitation and from infiltration from streams; water present below ground from ponds and lakes; water that flows or ponds underground.

habitat: The range of environmental factors at a particular location supporting specific plant and animal communities.

hydraulic: Of or involving a fluid, especially water, under pressure.

hydrographic: The scientific description and analysis of the physical conditions, boundaries, flow, and related characteristics of the earth's surface waters. 

hydrology: The scientific study of the properties, distribution, and effects of water on the earth's surface, in the soil and underlying rocks, and in the atmosphere.

hypersaline: Marked by increased salt in a saline solution.  Applies to highly saline brines, typically several times as salty as seawater.

intermittent stream: A stream filled with water for only a portion of the year.

intertidal habitat: The tidal area between the mean lower low water (MLLW) and mean higher high water (MHHW) which is alternately exposed and covered by water twice daily.

invasive species: A species that is 1) non-native (exotic) to the ecosystem under consideration and 2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health

jurisdictional wetlands: Wetlands which meet the criteria of "waters of the United States" and are thereby under the jurisdiction of the U.  S.  Army Corps of Engineers and the U.S.  EPA  The definition developed by the Corps considers as wetlands those areas which "...are inundated or saturated by surface or ground water at a frequency and duration to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions."  Under this definition, all three of the following conditions must be present: a) a dominance of wetland plants; b) hydric soils (soils with low oxygen concentrations in the upper layers during the growing season); and c) wetlands hydrology.

lagoon: A coastal body of water separated from the ocean by a sand bar, which may periodically breach, opening the lagoon to the ocean for a time.  Lagoons can form where a river meets the ocean (an estuarine lagoon), or without the influence of a river.

levee: A barrier constructed to contain the flow of water, prevent flooding, or to keep out the sea.

mammal: Any of various warm-blooded vertebrate animals of the class Mammalia, including humans, characterized by a covering of hair on the skin and, in the female, milk-producing mammary glands for nourishing the young.

managed ponds: Diked wetland, generally shallow open water habitats.

marsh: A common term applied to describe treeless wetlands characterized by shallow water and abundant emergent, floating, and submerged wetland flora.  Typically found in shallow basins, on lake margins, along low gradient rivers, and in calm tidal areas.  Marshes may be fresh, brackish or saline, depending on their water source(s).

MHW: Mean High Water, the average height of all the high tides.

MHHW: Mean Higher High Water, the average height of the higher of the two daily high tides.

migratory: Moving regularly or occasionally from one region or climate to another; as, migratory birds. 

MLW: Mean Low Water, the average height of all low water heights.

MLLW: Mean Lower Low Water, the average height of the lower of the two daily low tides.

morphology: That branch of biology which deals with the structure of animals and plants.

MTL: Mean Tide Level

mudflat: Flat un-vegetated wetlands subject to periodic flooding and minor wave action.  The area, which lies between tidal marshes and the edge of the Bay at low tide, provides habitat for invertebrates, fish, and shorebirds.

Navigation channel: The buoyed, dredged, and policed waterway through which ships proceed, especially in general shallow areas. 

native species: Species which have lived in a particular region or area for an extended period of time.

nonpoint source: A diffuse source of pollution that cannot be attributed to a clearly identifiable, specific physical location or a defined discharge channel.  This includes the nutrients that run off the ground from any land use - croplands, feedlots, lawns, parking lots, streets, forests, etc. - and enter waterways.  It also includes nutrients that enter through air pollution, through the groundwater, or from septic systems.

nutrient load: Quantity of plant nutrients added to a given area (e.g., a pond).

outfall: The place where a sewer, drain, or stream discharges.

pannes: See salt pannes

permeability: The degree to which something (e.g., an earthen structure) can be penetrated by a liquid. 

pH: Measure of the acidity or alkalinity (basicity) of water (pH 7 is neutral, increasing values indicate alkalinity and decreasing value indicate acidity).

phytoplankton: Small (often microscopic) aquatic plants suspended in water. 

point source: A source of pollution that can be attributed to a specific physical location; an identifiable, end of pipe "point."  The vast majority of point source discharges of plant nutrients are from wastewater treatment plants, although some come from industries.

ppt: Parts per thousand (used as a measurement of salinity); the salinity of ocean water is approximately 35 ppt.

Proposed Species of Concern (Federal Definition): A group of organisms for which a general notice has been published in a local newspaper and a proposed rule for listing has been published in the Federal Register.  A species that may or may not be listed in the future (formerly ìC2 candidate speciesî or ìspecies under consideration for listing for which there is insufficient information to support listingî).

Rare (State Definition): A species, subspecies, or variety is rare when, although not presently threatened with extinction, it is in such small numbers throughout its range that it may become endangered if its present environment worsens.

restoration: The return of an ecosystem to a close approximation of its condition prior to disturbance.

riparian area:  Riparian refers to the area of land adjacent to a body of water, stream, river, marsh, or shoreline, forming a transition between the aquatic and the terrestrial environment. 

saline: Of, relating to, or containing salt; salty.

salinity: A measure of the salt concentration of water; higher salinity means more dissolved salts.

salt marsh: A coastal habitat consisting of salt-resistant plants residing in an organic-rich sediment.

salt pannes: Salt pannes are shallow, generally unvegetated areas that form shallow ponds on the salt marsh.  They become hypersaline in late summer.  Salt pannes often contain fish populations and provide valuable habitat for shorebirds when flooded. 

salt ponds: Commercial facilities that extract salt from Bay water by evaporation.  Algae are the main vegetation, brine shrimp and birds the primary inhabitants.

salt marsh: A coastal habitat consisting of salt-resistant plants residing in an organic-rich sediment.

seasonal wetlands: Shallow depressions that typically contain standing water during the rainy season but become drier, or dry out, in summer and fall.  They include diked (formerly tidal) salt and brackish marshes, farmed wetlands, abandoned salt ponds, inland freshwater marshes and vernal pools. 

sedimentation: The deposition or accumulation of sediment. 

Sensitive Species (Federal definition): Those plant and animal species identified by a regional forester for which population viability is a concern, as evidenced by significant current or predicted downward trends in population numbers or density, or significant current or predicted downward trends in habitat capability that would reduce a species' existing distribution

sloughs: A narrow, winding waterway edged with marshy and muddy ground.  These water bodies are distinguished by low flow or stagnant waters.

spartina (alterniflora): Smooth cordgrass, an invasive species

Species of Concern (Federal Definition): An informal term that refers to those species which the US Fish and Wildlife Service believes might be in need of concentrated conservation actions.  (Formerly known as Category 1 or 2 Candidate)

Species of Special Concern (State Definition): Native species or subspecies that have become vulnerable to extinction because of declining population levels, limited ranges, or rarity.  The goal is to prevent these animals and plants from becoming endangered by addressing the issues of concern early enough to secure long term viability for these species.

submerged: Below water.

submerged plants: Plants growing with their root, stems, and leaves completely under the surface of the water. 

subtidal habitat: Areas below mean lower low water (MLLW) that are covered by water most of the time.

swamp: A seasonally flooded bottomland with more woody plants than a marsh and better drainage than a bog. 

Threatened (State Definition): A native species or subspecies of a bird, mammal, fish, amphibian, reptile, or plant that, although not presently threatened with extinction, is likely to become an endangered species in the foreseeable future in the absence of the special protection and management efforts. 

Threatened (Federal Definition): Any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.

tidal marsh: Wetlands with fresh water, brackish water, or salt water along tidal shores.

tidal mud flat: The unvegetated shoreline area exposed to air during low tide. 

toxic: The property of being poisonous, of causing death or severe temporary or permanent damage to an organism. 

toxicity: The degree to which a substance is toxic

turbidity: The relative clarity of water, which depends in part on the material in suspension in the water.

upland: Ground elevated above the lowlands along rivers or shorelines.

watershed: An area of land where all of the ground water and surface water  drains to  the same water body (typically a river or creek).