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Sablefish: A long-bodied Pacific fish with dark skin and oily flesh. Adults live in very deep water.
Sacrificial anode: Process whereby zinc covers an iron part on a boat to reduce corrosion. Usually placed on a outboard motor on base plate.
Salinity: The total amount of dissolved material (mostly salt) in water; sea water is approximately 3.5 percent salt.
Salmon: A family of fishes that breed in rivers but live most of their adult lives at sea. Salmon have orange or pink flesh. For centuries, salmon have been important food fish to people of many nations. When they're ready to breed, most salmon find their way from the ocean back to the same stream where they were born.
Salmon run: A population of salmon that breeds in a certain river. Some rivers have several different runs of salmon that breed at different times of the year.
Sand dollar: A flattened echinoderm that looks something like an old silver dollar coin.
Sand dunes: Mounds of sand, usually on the beach facing the surf. Containing specific types of vegetation. The faster the winds, the bigger the dunes.
Sanderling: A short-legged shorebird. When sanderlings search for food, they scamper up and down the beach following the waves.
Sandpiper: A small shorebird with short legs that searches for food along the sandy shore.
Sand star: A species of sea star that lives on the sandy seafloor.
Scales: Thin, flat, hard plates that cover a fish.
Scaleworm: A member of a group of worms with segmented bodies and bristles on each segment; scaleworms and their relatives are some of the most abundant animals in the ocean.
Scallop: A mollusc similar to a clam, but with deep ridges in its shell.
Scavenger: An animal that feeds on dead organisms.
Schooling: Behavioural grouping together of fish, which then usually move together as a group.
Scope: The ratio between the length of an anchor rope and the depth of the water in which a vessel is anchored.
Scuba: Acronym of self-contained underwater breathing apparatus or aqualung equipment which provides air to a diver without the need for an airtube to the surface.
Sculpin: A family of small fishes that have long bodies, broad pectoral fins, and wide mouths. Many species of sculpins live in the rocky intertidal zone.
Sea: A subdivision of an ocean.
Sea fan: A member of a group of corals that form delicate, fan-shaped skeletons.
Seal: A member of a group of marine mammals that have fur, blubber, and no earlobes on the sides of their heads. Seals are graceful swimmers, but move only clumsily on land.
Sea lion: A member of a group of marine mammals that have fur, blubber, and small earlobes visible on the sides of their heads. Sea lions are excellent swimmers but can also move fairly quickly on shore.
Sea pen: An invertebrate animal that lives as a colony of individuals arranged in a shape that looks like an old-fashioned quill pen.
Sea star: An invertebrate animal, related to sea urchins and sand dollars, with a star-shaped body. Many species of sea star have five points; some have more.
Sea time: Logged time spent at sea.
Sea turtle: A member of a group of species of turtles adapted for life in the sea. Sea turtles have flipper-like legs and come to shore only to lay their eggs.
Seafood: Food from the sea.
Seamount: An individual peak extending over 1000 m above the ocean floor.
Seawater quality: Term used to indicate health of sea water. Good water quality is essential for fish farming, swimming, surfing etc.
Seaweed: Any of the large plants that grow in the sea, especially marine algae like kelp.
Secchi disc: Device used to measure turbidity.
Second order consumer: Animal which eats a first order consumer.
Secondary wastewater treatment: After primary treatment of sewage, the removal of biodegradable organic matter from sewage using bacteria and other micro-organisms, inactivated sludge or trickle filters.
Sediment: Soil particles, sand and other minerals or organic matter eroded from land and carried in surface waters.
Sedimentary rock: A rock formed from the consolidation of loose sediment or from chemical precipitation, such as sandstone and limestone.
Seining: To run a net around a school of fish.
Semi-submersible submarine: Submarine that carries passengers. Passengers travel in an underwater viewing chamber but the skipper drives from a wheelhouse above sea-level.
Septic tank: A tank buried in the ground where household sewage is gradually decomposed by bacteria. Most houses that are not hooked to a sewer line flush waste into a septic tank.
Serpent snail: A snail of the genus Serpulorbis, which makes a shell that twists and turns.
Serrated: Having a series of scallop-shaped notches along one side. A bread knife often has a serrated edge.
Sessile: Not able to move from place to place. Benthic organisms that are attached to hard surfaces or the seabed.
Sewage: Wastewater produced from household and industry.
Sewerage pipes: The pipes that contain the sewage wastewater.
Sexual dimorphism: A distinct difference in appearance between males and females of the same species
Shackle: A U-shaped metal fitting with a cross pin or clevis pin that fits across the opening of the U as a closure.
Shale: A soft type of rock that often breaks into big flat pieces. Shale is formed when mud is pressed into rock over millions of years.
Shark: A member of a large group of primitive fishes with skeletons made of cartilage. Skates and rays are members of the shark family.
Sheets: Ropes used to adjust sails.
Shellfish: Aquatic animals with shells, e.g. crustaceans (prawns, lobsters) and molluscs (e.g. oysters, scallops, clams).
Shipmaster: Person in charge of a ship.
Shipwreck: A ship that has sunk to the bottom of the sea or run aground so that it cannot move off where it has became stuck.
Shipwright: A person employed in the construction or repair of ships.
Shorebird: A bird adapted to live and find food along the seashore.
Shore crab: A small crab that lives and feeds along the seashore. There are several species of shore crabs.
Silica: A hard, glassy mineral. Quartz and opal are two forms of silica. Since much sand is made of quartz, silica is very common in sand. Some marine organisms use silica to build their shells.
Silt: Soil that runs off the land and accumulates where water slows down.
Siltation: The process of being covered with a layer of fine mud, silt or sand
Sinkers: Weighted objects used to take hooks and bait down into the water when fishing.
Siphon: A tube. Clams and many other molluscs breathe through siphons.
Siphonophore: A type of jelly that’s made of many smaller members that live and work together as one unit; a colonial jelly.
Skate: An egg-laying fish, related to sharks and rays, that has a cartilaginous skeleton, a broad, flat body and a pointed snout.
Skinned: To remove the skin when cooking fish.
Skipper: Person in charge of a ship.
Slack water: Water at the top or bottom of the tides. Usually associated with no currents.
Slick: Oil lying on the top of water.
Slough: A marshland or estuary where fresh water meets the sea.
Smelt: A small, schooling fish. Many larger fishes eat smelt.
Snail: A member of a group of gastropod molluscs; most species secrete a spiral shell for protection. Some species of snails don't make shells and are known as slugs.
Snap: Surfing term used to describe quick turning on the wave.
Snorkel: Tube enabling a person to breathe underwater.
Sodium thiosulphate: Chemical used in dissolved oxygen test. Number of drops used in the test equals the parts per million.
Solute: A substance dissolved in a solution. Salts are the solute in salt water.
Solution: A liquid (or solid) containing one or more solutes dissolved in a solvent; e.g. salt water.
Solvent: A substance that can dissolve other substances.
Sonar: The use of sound waves to detect underwater objects, such as schools of fish. A system that uses transmitted and reflected sound waves to find objects under water.
Sounding: Measuring the depth of water beneath a ship.
Southern Oscillation Index: An index calculated from the pressure difference between Darwin and Tahiti. Abbreviates to SOI.
Spark plugs: Device inserted into internal combustion engine, containing two terminals between which passes an electric spark.
Spat: The spawn of an oyster or shellfish.
Spawn: To breed; especially, to breed by releasing eggs and sperm into the water.
Species: A particular type of plant, animal, or other organism. Species differ from one another in at least one characteristic, and generally do not interbreed. In biology, species is a category that's part of the scientific system for grouping together related plants, animals and other organisms (kingdom, phylum, class, order, family, genus, species).
Spectrum: A series of coloured bands of light diffracted and arranged in order of their wavelength--red, orange, yellow, green, blue, violet. A rainbow is an example of a spectrum.
Sperm: Male reproductive cells.
Spicules: Structures found in sponges and soft corals.
Spinner dolphin: A species of small dolphin, which often spins in the air when it leaps.
Sponges: A group of invertebrates with very simple bodies that spend their lives in one place. Some kinds form a tough, flexible skeleton full of holes or pores. People harvest these skeletons; they were the first sponges used for bathing and cleaning.
Spore: A reproductive structure, formed without the union of sexual cells, which can give rise to a new organism. Fungi, algae and many other organisms produce spores rather than seeds.
Sporophyte generation: Asexual generation in plants.
Spotted dolphin: A species of dolphin with spotted skin.
Spriggots: Small projections on the mouthpiece of a snorkel.
Spring tide: The tide that occurs at new or full Moon when the gravitational influence of the Sun is working primarily in line with the Moon, so that the tidal range is high.
Squarespot: A small, colorful fish from Pacific coral reefs.
Squid: A soft-bodied marine animal with two long tentacles for catching food, eight or more shorter arms, and a streamlined body adapted for swimming quickly through open water. Squid are related to octopuses and cuttlefishes.
Stainless steel: Hard steel alloyed with high percentage of chromium. Resists rusting in sea water.
Starboard: The right side of a boat, as seen from aboard facing the bow.
Starter cord: Cord attached to an outboard motor. Pulled to start the engine.
Sternum: Long bone in the centre line of humans connecting ribs. Often called the breastbone.
Stevedoring: A firm or individual engaged in the loading and unloading of ships.
Stinging cell (nematocyst): The stinging capsule on the tentacles of an anemone or jelly, which the animal uses to protect itself or to capture food.
Stipe: The stem-like part of a seaweed thallus.
Stocks: Stocks of fish are fish populations--the total number of fish of each species.
Stormwater: Water off the roads and roof of houses. Must not be connected to sewerage system. Often gets polluted by human urban activities.
Stormwater taskforce: Group of individuals set up by the Surfrider Foundation to clean up stormwater drains.
Straits: Narrow body of water bordered on either side by land.
Stranded: Washed up on shore.
Structural characteristic: A characteristic of an organism that sets species apart from another, e.g. segments in the body are a structural characteristic.
Subduction: The process in which one huge plate of the earth's crust descends beneath another plate.
Sub-littoral zone: Zone on a rocky or reef zone below low water mark.
Submarine canyon: A long, narrow, steep-walled undersea valley.
Submergence: Process by which coastlines become covered with water from rising sea-levels.
Submersible: A submarine vehicle used in oceanographic studies.
Subsidy: money paid by a government to encourage people do something the government believes is desirable. Many governments once offered subsidies to help people buy fishing boats.
Substrate: The surface or material on which an organism lives--rock, sand, mud, pilings, shells.
Succession: Replacement of populations in a habitat through a regular progression to a climax (mature) community; brought about by organisms that change the environment.
Sulfide: A compound of sulfur.
Sulfur: A pale yellow, nonmetallic chemical element. Sulfur compounds often have a strong smell, like rotten eggs.
Sunburn: Inflamed state of the skin caused by being out in the sun too long. Very dangerous and causes skin cancer.
Supra-littoral zone: Zone on a rocky or reef zone above high water mark.
Supra-tidal zone: The seashore zone below the inter-tidal zone exposed to the air at high tide.
Surfperches: A family of fishes with rounded bodies that live close to shore and feed in the rough water of the surf zone.
Surfrider Foundation: Group of surfers who care about the sea and want to see the end to ocean outfalls of sewage. Anyone can join. Write to PO Box 1441, Dee Why NSW 2009.
Surf zone: The area of rough water next to the land, where ocean waves hit the shore.
Suspension feeder: An animal that eats by filtering out tiny particles of organic material suspended in the water.
Sustainable: Able to last; able to continue into the future.
Swarms: Jelly swarms happen when great aggregations of animals are brought together, blown by strong winds and currents.
Swell: A wave, or succession of waves (originally generated by winds), that have left their area of generation and have moved into areas of weaker wind.
Swimbladder: A gas- or oil-filled structure in bony fish that is used to regulate buoyancy. A swimbladder is like a float; without it, the fish would sink to the bottom if it stopped swimming.
Swordfish: A large predatory fish with a long, swordlike bill at the tip of its snout. Swordfish are famous for their speed and strength. They're also heavily fished for their meat.
Symbiosis: A mutual relationship between two species in which both benefit.
Symmetry: Body form of animals. Can be bilateral or radial.
Synthetic: Materials formed by chemical process usually involving rubber and resins.
