Glossary | S

Salt pan
small dip in high meadows where water is stranded after the tide falls
Saltmarsh
transition area of salt tolerant plants between terrestrial and marine ecosystems that are occasionally flooded by high tides; high marsh in contrast to low marsh mudflat
Sargassum
species of brown algae that is primarily found in the Sargasso Sea
Scavenger
animal that feeds on dead plants and animals
Scrape
depression in the sand or substrate that some shorebirds birds create. The bird leans forward on its breast and scratches with its feet while rotating its body axis.
SCUBA
device that lets a diver breathe air while under water (letters stand for Self-Contained Underwater Breathing Apparatus
Scyphozoa
class of Cniderians that includes jellies with a medusa form; true jellies
Sea
subdivision of the ocean, a smaller and shallower body of water than the ocean; often semi-enclosed or marginal where between land and the ocean
Seagrass
collective name for vascular marine flowering plants that grow in shallow waters on soft substrate
Seamount
peaked, underwater mountain rising at least 1,000m (3,280ft) above the ocean floor
Seaweed
collective name for non-vascular, non-microscopic plants that usually contain chlorophyll; commonly called algae
Secondary consumers
carnivorous animals
Sedentary
remaining in one place
Semidiurnal tide
tide that has two high and two low waters in each tidal day
Semiprecocial
chicks hatch with eyes open, covered with down, and able to walk; but unlike fully precocial chicks, remain in or near the nest for several weeks
Sessile
permanently attached to a substrate
Sexual dimorphism
differences between males and females in external appearance or behavior
Shellfish
aquatic animal with a shell; includes mollusks and crustaceans
Shute
bony plate
Siliceous
containing silica
Siphon
tube or tube-like part of an animal through which air, food or water passes
Slough
swamp, bog, marsh or pond that is part of an inlet or backwater
Solitary
living singly except during breeding and/or raising young
Spawn
to produce and deposit eggs
Species
distinctive group of organisms that can successfully interbreed and produce viable offspring
Species diversity
numbers of different species and their relative abundance in a given area
Spermatophore
capsule enclosing a packet of sperm produced by males of some animals that is directly transferred to the reproductive part of a famale's body
Spiracle
dorsal openings in the head region of some cartilaginous fishes through which water is drawn and passed over the gills
Spiracles
openings that allow entrance, passage, or exit of a gas or vapor, esp. of air
Statocyst
specialized sacs or organs on the rim of the bell and tentacle bases of jellies that assist animal in maintaining balance in the water column by sensing the pull of gravity; balance organ
Stipe
stem-like part of a kelp plant that connects the holdfast to the blades
Stipe
stem-like part of a kelp plant that connects the holdfast to the blades
Strobilia
multi-organism columnar pancake-like of very small jellies produced by a polyp; as jellies break off, the polyp is said to be 'strobilating'
Strobilization
budding: asexual transformation into reproductive process
Sublittoral (subtidal) zone
benthic zone from the low tide mark to the outer edge of the continental shelf
Subsistence
barest means needed to sustain life
Subspecies
a genetically distinct geographical subunit of a species. Also called race.
Substrate
any surface on which a plant or animal lives or on which a material sticks
Subtidal
below the intertidal, or below the level of the lowest tide. Also called sublittorial.
Supralittoral zone
narrow benthic zone on shores above high water mark that only becomes wet when there are storms or spray
Surfline
area near shore where the waves break
Surge
movement of a mass of water
Surge channel
channel along the edge of rocks or reefs in which the water level fluctuates with wave or tidal action
Suspension-feeder
an animal that filters out debris, detritus, or other particles suspended in the surrounding water
Suspension-feeder
an animal that filters out debris, detritus, or other particles suspended in the surrounding water
Sustenance
nourishment; that which sustains life
Swell
a large ocean wave that moves steadily without breaking
Swim bladder
gas-filled bladder of a fish that helps it maintain its position in the water column
Symbiosis
close relationship between two organisms of different species that is often of mutual benefit