Glossary

abdomen	the belly region of a vertebrate animal, or the hind segment of the body of an insect, crustacean or other arthropod.
abdominal pelvics	pelvic fins located on the abdomen far behind the pectoral fins; pelvic bones do not attach to pectoral girdle.
abyss	a very deep region.
abyssal plain	the flattened floor of the deep ocean offshore from the continental margin.
abyssal zone	the deep sea region below 13,000 feet (4,000 meters).
adaptation	a characteristic body part, shape or behaviour that helps a plant or animal survive in its environment.
absolute recruitment	the number of fish which grow into the catchable size range in a unit of time (usually a year).
accessory pelvic appendage	a tapered fleshy lobe above the base of the pelvic fin.
adfluvial	possessing a life history trait of migrating between lakes or rivers and streams.
adipose fin	a small fleshy fin with no rays, located between the dorsal and caudal fins.
aerobic	containing oxygen or requiring oxygen.
albatross	a large seabird that spends much of its life wandering over the open ocean far from land.
alevin	the developmental life stage of young salmonids and trout that are between the egg and fry stage. The alevin has not absorbed its yolk sac and has not emerged from the spawning gravels.
*algae (sing.* alga)**	a large group of primitive plants that live mostly in water. Kelp and other seaweeds are algae. Algae have simple bodies—many kinds exist as single cells.
algin	a slippery substance extracted from brown algae, including kelp. Algin is used in paint, toothpaste, ice cream and many other products because it thickens liquids and binds oily and watery liquids together.
amphipods	small, shrimplike crustaceans.
anadromous	fish that hatch rear in fresh water, migrate to the ocean (salt water) to grow and mature, and migrate back to fresh water to spawn and reproduce.
anaerobic	not containing oxygen or not requiring oxygen.
anal fin	the fin located on the ventral median line and behind the anus.
anchovy	a small, silvery fish that swims in big schools. Anchovies are eaten by tuna, salmon, penguins and many other predators.
anemone	a sea animal with a crown of tentacles at the top of a fleshy polyp or stalk. The tentacles contain stinging cells (cnidocytes).
angling device	a modified dorsal fin or chin barbel on some deep sea fishes that acts like a rod and bait to attract prey or mates.
anoxic	without oxygen.
antenna	a long, slender organ or feeler located on the head of an insect, crustacean or other arthropod; or any long, slender rod used for gathering or transmitting information.
antibiotic	a medicine that kills disease-causing bacteria.
aquaculture	fish farming.
aquatic	of the water; living in the water.
arthropod	a large group of invertebrate animals with jointed legs, including the insects, scorpions, crustaceans and spiders.
atmospheric pressure	the pressure of the air here on the Earth's surface. At sea level, atmospheric pressure equals 14.7 pounds per square inch (2.6 kilograms per square centimeter). This amount of pressure is known to scientists as one atmosphere. People and other land animals are adapted to one atmosphere of pressure and thrive on the Earth's surface. But water is much heavier than air, and as we dive into the ocean, pressure increases. Divers feel an extra atmosphere's worth of pressure with every 33 foot (10 meter) increase in depth.
atoll	a ring-shaped coral reef that forms around a volcanic island.
aviary	an enclosure where birds can fly around freely.
avocet	a shorebird with long legs and a very long, upward-curving bill.

B
*bacterium (pl.* bacteria)**	one-celled organisms so small they can only be seen with a microscope. Some bacteria cause diseases, like pneumonia and tuberculosis, but others are necessary to all life on Earth because they break down dead organic material.
baleen	a tough, horny material growing in comblike fringes from the upper jaws of some species of whales.
bamboo shark	shark of the genus Chiloscyllium, which live in shallow waters around coral reefs and have bamboolike markings when young.
Banggai cardinalfish	a tiny coral reef fish with large eyes and patterned skin, found mainly near the island of Banggai (near Indonesia).
barbel	a long, slender organ extending from the chins of some fishes, sometimes used as a lure to attract prey.
barnacle	an invertebrate animal that lives in a hard shell attached to a rock, boat bottom or other hard surface. Barnacle shells are cone-shaped, like tiny volcanoes. Barnacles are crustaceans, related to crabs, shrimp and lobsters.
bat ray	a species of ray that has long fins that look like bat wings.
bathyal	the deep sea region between 600 and 6,000 feet (183 to 1,830 meters).
beach hopper	a tiny, shrimplike animal that lives among piles of kelp washed up on beaches; they hop like fleas to get away and are sometimes called "sand fleas."
bell	the round, non-stinging part of umbrella-shaped jellies known as medusas.
bends	"the bends" is a painful condition caused when nitrogen gas forms bubbles in a diver's blood. Scuba divers risk getting the bends if they come up too fast from a deep dive.
benthic	on or near the bottom of a lake, river or ocean.
benthic echinoderm	a sea star, sea urchin or other echinoderm that lives on or near the seafloor.
benthic jelly	a jelly that lives on or very near the seafloor.
benthic mollusc	one of a group of soft-bodied animals that live on or near the seafloor. Deep sea snails and clams are benthic molluscs.
beta carotene	a natural yellow pigment, present in many vegetables and extracted from green algae.
bioluminescence	light made by a living organism.
bloom	jelly blooms are the result of reproduction events where, in its asexual stage, jellies bud multiple polyps, and these polyps divide. It’s thought that blooms of jellies occur when waters are overfished or when a species is accidentally introduced into an environment and begins to take over.
blubber	a thick layer of fat under the skin of whales, seals and their relatives. Blubber helps keep these marine mammals warm.
bluefin tuna	a group of tuna species with iridescent blue skin. Bluefin are some of the ocean's biggest, fastest predators. They live in cold water and can weigh up to 2,000 pounds (907 kilograms).
blue-spotted boxfish	a small tropical fish with a square, boxlike body. The "box" is stiff body armor made of stuck-together scales.
bonito	a sleek, fast-swimming fish in the tuna family.
bottom trawling	a cone-shaped net is dragged along the seafloor. Some bottom trawl nets are fixed with chains that slap the seabed, "tickling" fishes into the net above. Other "rockhopper" trawls are fitted with heavy tires that roll the net along rough, rocky seafloor, ensuring the net isn't snagged on the bottom.
bray	a loud call of blackfooted penguins and others in the genus Spheniscus. Penguins bray when mating or defending territory.
brittle star	a sea star that has a small central body surrounded by many long, brittle arms.
brood	to sit on eggs or to protect hatched young by sheltering them with the wings or the body.
bryozoan	any member of the phylum Bryozoa, marine invertebrate animals with planktonic larvae that settle and form attached branched or mossy colonies by budding. Some bryozoans encrust rocky surfaces, shells or seaweeds.
budding	the process by which young jellies, called polyps, produce identical polyps.
buoy	a floating object anchored in place. Buoys are often used to hold equipment for measuring air temperature, water temperature, wind speed or salinity.
burrower	an animal that digs a hole to live in.
butterflyfish	a member of a large family of colourful coral reef fishes with flattened bodies and small mouths.
bycatch	unwanted fishes and animals caught accidentally in fishing gear and discarded overboard, dead or dying.

C
cacophonous	a loud and noisy.
caerulean damselfish	a small, bright blue coral reef fish found in the Pacific and Indian Oceans.
camouflage	colours or patterns that make something hard to see. Many animals use camouflage to hide from their predators.
canopy	the top part of a forest. In the kelp forest, the canopy is the top layer where kelp fronds float on the surface.
canyon wall	a side of a canyon. Canyon walls can be steep or gently sloping. Many benthic organisms live on the walls of Monterey Canyon.
capelin	a small, schooling fish from the Arctic and northernmost parts of the Pacific Oceans. Predatory fishes, penguins and whales eat capelin. Also called capelin anchovy.
carp	a freshwater fish with large scales and small barbels near its mouth. People have raised carp as food since ancient times.
carrageenan	an edible substance extracted from red algae, used as a thickener in foods, cosmetics and other products.
cartilage	tough, flexible tissue (like the tissue at the tip of your nose) that forms the skeleton of sharks, skates and rays.
catfish	a member of a group of fishes with smooth skin, large flat heads and long barbels near the mouth. There are marine and freshwater catfishes. Some of the freshwater species are raised easily in ponds.
cavort	the group of molluscs that includes octopuses, squid, nautiluses and cuttlefishes. Cephalopods all have many arms and well-developed eyes.
cetacean	any member of the group of marine mammals that includes whales, dolphins and porpoises.
chameleon	a lizard that can change colour to match its background.
channel	the deepest part of a stream or harbour, where most of the water flows.
charade	movements that are meant to trick or deceive.
chemoreception	the ability to sense chemicals in the environment.
chemosynthesis	the process by which some bacteria use chemicals (like hydrogen sulfide) to provide the energy they need for life.
Chilean seabass	a fish that lives in the deep sea near Chile. This species was called the "Patagonian toothfish" until fish sellers decided it needed a name that would sound better to seafood buyers. This slow-growing species is in serious trouble from overfishing.
chlorophyll	the green chemical that lets plants turn sunlight into energy through the process called photosynthesis.
chordate	an animal (phylum Chordata) that has, at some time in their development, a notochord, gill slits and a dorsal nerve cord. Chordates include vertebrates and tunicates.
clam	a mollusc that lives between two flattened shells.
class	in biology, 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). Class is the category that ranks below a phylum and above an order.
cleaner wrass	small fish of the wrasse family that pick parasites off larger fishes.
cod	a large fish that often lives close to the seafloor. Cod have firm white flesh; for centuries, cod have been important to people of many nations as a food fishes.
coelenterate	any of the various invertebrate animals of the phylum Cnidaria, characterized by a radially symmetrical body with a saclike internal cavity, including the jellies, hydras, sea anemones and corals.
cold seep	a habitat on the deep seafloor where cold fluids seep from the rocks. These fluids contain chemicals (sulfides and/or methane) that bacteria use as their energy source. Cold seep habitats support communities of animals that rely upon these bacteria for food, and are therefore part of a food web based on chemicals instead of sunlight.
community	all of the plants and animals living in a specific area (habitat), often described by the most abundant or obvious organisms. The kelp forest community means all the animals and plants that are part of the kelp forest.
conservation	the practice of protecting nature from loss or damage.
continental crust	the Earth's crust that includes continents and the continental shelves.
continental margin	the ocean floor from the shore of a continent to the abyssal plain.
continental rise	part of the continental margin; the ocean floor from the continental slope to the abyssal plain.
continental shelf	the submerged shelf of land that slopes gradually from the exposed edge of a continent to where the drop-off to the deep seafloor begins.
continental slope	part of the continental margin; the ocean floor from the continental shelf to the continental rise or oceanic trench, usually to a depth of about 660 feet (200 meters).
copepod	a member of a large group of species of tiny shrimplike crustaceans.
coral	a group of invertebrate animals related to sea anemones. Individual coral animals have soft bodies topped by a ring of stinging tentacles for catching food. Some kinds of coral build hard limestone skeletons; when they die, other corals build on top until a great reef is formed.
corrugation	a row of ridges.
crab	a crustacean with a rounded thorax, a short abdomen tucked under its body, and, in most species, large front claws.
craggy	rough; full of cracks and ridges.
creche	a group of youngsters, all about the same age, who stay together for protection.
crown-of-thorns	a sea star covered with long, thornlike spines; one of the most important predators in the coral reefs.
crustacean	an invertebrate animal with a hard shell and many jointed legs. Shrimp, crabs, lobsters and crayfishes are crustaceans.
ctenophore	a marine animal belonging to the phylum Ctenophora, which usually has a transparent, jellylike body and eight rows of comblike cilia (tiny hairs) for swimming.
culture	in biology, to raise or grow an organism in a laboratory or other controlled environment.
cuttlefish	a soft-bodied marine animal with many arms, related to octopuses and squid.

D
*datum (pl.* data)**	information, usually expressed as numbers. Data are often used in analysis to draw conclusions that support or reject a hypothesis.
debris flows	relatively slow movement of sediments downward over gently sloping terrain.
decomposer	an organism, like a bacterium, that causes the decay of dead plant and animal matter.
deep scattering layer	a concentrated layer of midwater organisms that can reflect and scatter sound waves produced by sonar devices.
deep sea	the deep, lower regions of the ocean where sunlight doesn't penetrate.
delegate	(noun) a representative who speaks for a group of people at a meeting or lawmaking assembly. (verb) To give someone authority or responsibility to carry out a task.
deposit feeder	an animal that eats organic matter that's been deposited on or in the seafloor.
depth sounder	an electronic device that measures the depth of water very precisely.
detritus	particles from decaying plants and animals.
device	an instrument, tool or machine designed and constructed to perform a certain task.
display	a set of calls or motions done by a bird or animal to convey a particular message. Penguins might do a courtship display to attract a mate, or an aggressive display to warn off an enemy.
diurnal	daily.
dogfish	a species of small shark.
doliolid	a deep-sea, pelagic tunicate.
dolphin	a member of a group of small whales that have sharp, pointed teeth and pointed snouts.
dorsal	on or toward the back or topside (opposite of ventral).
dragging	another term for bottom trawling, a fishing method in which large nets are dragged along the seafloor to catch seafood.
dredge	a net attached to a frame that's dragged along the ocean floor to collect animals.
drift kelp	a piece of seaweed that breaks free of its holdfast, drifts with the ocean currents and sinks to the seafloor.
dune	a hill of sand. The wind pushes sand from the beach into dunes.

E
ebb	to flow away. At low tide, water ebbs back into the ocean.
echinoderm	one of a group of invertebrate animals identified by their spiny skin, including sea stars, sea urchins and sand dollars. "Echinos" means spiny; "derma" means skin.
echo sounder	a machine that determines water depth by measuring the time it takes sound waves to reach the seafloor and bounce or echo back to the surface.
ecology	the scientific study of the relationships between plants, animals and their environment.
ecosystem	the natural system in which energy and nutrients cycle between plants, animals and their environment.
eelgrass	a water plant with long, grasslike leaves. Eelgrass is one of the few flowering plants that lives in salt water.
egret	a wading bird with long legs.
El Niño	an unusual, warm surface current that flows out of the tropical Pacific Ocean and moves along the Pacific coasts of North and South America.
electroreceptor	an organ specialized to detect electric signals. Sharks have electroreceptors that help them find prey.
emulsifier	a substance that lets oil and water mix into a smooth liquid.
encrust	to cover with a layer or crust.
ephyra	a free-swimming young jelly produced when a polyp buds.
epipelagic	the upper sunlit ocean layers to 350 feet deep (107 meters), also called the photic zone.
estuary	is a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water mixes with fresh water.
evolution	the process of gradual change over long periods of time.
extinct	no longer alive; no longer in existence.
eyespot	a jelly’s light-sensing organ, usually found around the edge of the bell.

F
factory trawler	a large ship equipped with trawling gear to catch, clean and freeze fishes for market. Find out more about trawling and see an animation of how it works in the Seafood Watch Gear Types section.
family	in biology, 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). Family is the category that ranks below an order and above a genus.
fat innkeeper worm	a wormlike invertebrate that burrows in mud; it's called the innkeeper because many other small animals come to live in its burrow.
fault	a break in the rocks of the Earth's crust along which movement may occur, causing earthquakes.
feather-duster worm	a marine worm that lives in a leathery tube and sticks out a bright orange or purple crown of soft, feathery gills. When disturbed, it pulls the gills into the tube lightning-fast.
feces	solid waste that passes out of an animal's digestive tract.
feral	wild. Used to describe animals that are usually domesticated, like cats or pigs.
filter feeder	an animal that eats by filtering or straining small particles of food from the water.
fishery	the organized harvest of a certain species of fishes or shellfishes.
fishery management	the effort to regulate where, when and how people fish, and how many fishes they catch, to protect fish populations so that people can continue to fish. Most fishery management is done by government agencies.
fishing pressure	the amount of fishing for a certain species of fish or shellfish. If there's heavy fishing pressure on sharks, it means that fishermen are catching many sharks.
flat porcelain crab	a small crab with a smooth, shiny shell that lives in the intertidal zone.
flatfish	a general term for fishes like flounder, sole and halibut that have a flattened body with both eyes on the upper side.
flounder	a flatfish with a flattened body adapted for life on the seafloor.
fluke	the flat tail flipper of a whale or other marine mammal.
food chain	the relationship between plants and animals that shows who eats what. Energy is transferred from one organism to another through the food chain.
frond	a long, feathery leaf, or the leaflike blade of a kelp plant or other sea plant.
fungal	having to do with a mould, mushroom or other fungus.


G
gas bladder	a gas-filled sac found in many fishes. Gas bladders help provide buoyancy; they're also called swimbladders.
gastropod	a group of molluscs that travel on a single, muscular foot and often secrete a one-piece shell for protection. Snails, slugs, limpets and abalones are all gastropods.
genus	in biology, 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). Genus is the category that ranks below a family and above a species.
geology	the scientific study of rocks, the Earth's crust and the Earth's interior.
gill	an organ that an animal uses to breathe under water. Gills absorb oxygen from the water.
gill cover	the tough flap of tissue that covers a fish's gills.
gillnetting	a curtain of netting that hangs at various levels in the water column, suspended from floats or anchored to the seafloor. As fishes swim into the net, the spaces are large enough for the head of the fish to pass through, but not its body. The fishes will try to back out, entangling its gills in the net.
global positioning system (GPS)	an electronic system that uses signals from satellites to locate things far below on the surface of Earth or ocean. GPS technology is being used to make very accurate new maps of the Earth and its oceans. GPS devices let scientists and fishermen find their way very precisely.
godwit	a long-legged shorebird with a very long, straight bill.
golden-eye mysid	a shrimplike animal that lives on the seafloor. The golden-eye mysid was named for the way its eyes reflected the lights of remotely operated vehicles (ROVs) exploring the deep sea.
gorgonian	a member of a group of corals that grow in treelike shapes; some live in cold, deep water and grow very slowly.
guano	the droppings of birds or bats. In some places, like penguin colonies, huge deposits of guano build up over many years. People sometimes harvest this guano to use as fertilizer for farms and gardens.
guitarfish	a flattened fish in the shark family, not quite as flat as a skate or ray.
gullet	the throat.

H
habitat	a place fishes (and other animals) need to feed, breed, seek shelter and raise young.
hadal	the deep sea region below 20,000 feet (6,100 meters); the deep trenches.
hake	a fish, related to cod, that gathers in large schools. Hake live from the surface down to depths of 3,000 feet (914 meters).
halibut	a large flatfish with a flattened body adapted for life on the rocky seafloor.
hand raking	dragging a tined tool through sediment from the seafloor to separate plants and animals, usually clams, from sand and rock.
haptera	rootlike structures growing from the base of a kelp plant. Haptera form the holdfast that anchors the kelp to the rocky seafloor.
harlequin shrimp	a colourful shrimp from the coral reefs of the central Pacific.
harpooning	a traditional method for catching large fishes. The animal is manually speared with a 10- to 14-foot aluminum or wood harpoon attached to a long rope.
haul out	to climb up out of the water. Seals often haul out onto rocks.
head of the canyon	the shallow part at the beginning of an underwater canyon.
herbivore	an animal that eats plants.
hermaphrodite	an animal or plant with both male and female sexual organs.
hermit crab	a crab that protects itself by living inside an empty snail shell. There are many species of hermit crabs, some on land, some in the ocean.
herring	small, silvery fishes that swim in large schools.
holdfast	the rootlike part of a kelp plant that anchors the plant to the rocky seafloor.
hook and lining	Using a single pole and line with a single hook to manually catch fishes. Fishermen stand shoulder to shoulder on the deck with long poles and very short hooked lines and catch the fishes one by one.
horizontal	side-to-side, or stretched out flat like the horizon (opposite of vertical).
humus	nutrient-rich earth formed when plant material decays.
hydraulic dredging	removing sediment from the seafloor and using pressurized water jets to separate plants and animals, usually clams, from sand and rock.
hydrodynamics	the study of fluids in motion and the movement of objects through fluid.
hydroid	a sea animal which is typically very small and forms colonies consisting of a common stalk and delicate branching tubes bearing tiny, feeding polyps.
hydrothermal vent	a break in rock where warm or hot fluids seep out.
hypothermia	a dangerous loss of body warmth, which can cause death.
hypothesis	a scientific idea about how something works, before the idea has been tested. Scientists do experiments to test their hypothesis and see if the hypothesis is correct.

I
ichthyology	the scientific study of fishes.
inland	of, relating to, or located in the interior part of a country or region.
intertidal zone	the area along shore that is covered by water at high tide but is exposed to the air at low tide.
introduced predator	a non-native predator, introduced to a habitat through human activity.
invertebrate	an animal without a backbone.
iridescent	gleaming and flashing with many colors, like a peacock feather or a soap bubble.

J
jelly	also called jellyfish, a drifting sea animal with a soft central disk and long tentacles. Jellies are related to coral and sea anemones.

K
killdeer	a long-legged bird that lives both near the shore and in meadows far inland.
kilometre	a measure of length equal to 1,000 meters or about 5/8 of a mile.
kingdom	in biology, 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). Kingdom is the broadest category; plants are in a kingdom separate from animals.
krill	shrimplike crustaceans (mostly of the genus Euphausia) that grow to two inches (5 centimeters) long. Large populations of krill provide the main food for baleen whales and some kinds of fishes.

L
landed	brought to land, brought to shore; in the case of a fish, caught and brought to land.
landings	the quantities of fishes caught and brought to land by fishermen.
landslide	a mass of loosened rocks or earth that slides down a slope or hillside.
*larva (pl.* larvae)**	the young and immature form of an animal, which must change to become an adult.
leopard shark	a species of shark whose skin is marked with dramatic dark spots or blotches.
light absorption	the dimming of light as it passes through water or any other substance.
limpet	a group of gastropod molluscs, related to snails, which have simple shells shaped like a bowl or platter.
lingcod	a long-bodied fish that lives in cold Pacific waters.
lobster	a crustacean with a long abdomen and, in most species, large front claws.
longlining	a central fishing line, sometimes more than 50 miles long, strung with many smaller lines holding baited hooks. Pelagic longlines hang near the sea surface to target midwater fishes like tuna and swordfish. Demersal or "bottom" longlines float just off the ocean bottom to target fishes that live closer to the seafloor, such as cod or halibut.

M
mackerel	sleek silvery-blue fishes with stripes on its back, which swim in large schools. Mackerel are related to the tunas.
mahi mahi	a large fish that lives in the open ocean in warm parts of the world, also known as dolphinfish.
mammal	a warm-blooded animal that breathes air, has hair and feeds its young with milk.
maneuver	to control the movement and direction of something, as to maneuver a vehicle.
mangrove	a small tropical tree that grows in wetlands at the edge of the ocean. Mangrove forests are habitat for many kinds of fishes and other animals.
mantle	a portion of the body wall of a mollusc. In snails, clams and other molluscs with shells, the mantle secretes the shell. In octopuses and squid, the mantle is the outside of the body.
marine	of the sea.
marine betta	small, spotted fishes found on coral reefs of the western Pacific.
marine snow	clumps of dead or dying plants and animals that sink toward the seafloor. As they sink, bacteria and plankton feed on them. When many large particles sink, it looks like snow.
marsh	a wetland where plants grow with their roots in water and their tops in the air.
marsh wren	a small songbird that nests in marshes.
*medusa (pl.* medusae)**	the umbrella-shaped type of jelly.
mesoglea	the layer of gelatinous material that separates the inner and outer cell layers of a coelenterate.
mesopelagic	the twilight midwater zone 660 to 3,300 feet deep (200 to 1,000 meters), between the upper sunlit zone and the dark ocean depths.
mesotech sonar	a device on a remotely operated vehicle that's similar to an echo-sounder and shows the bathymetry (hills and valleys) of the seafloor.
metre	a length of measurement equal to 39.37 inches or about three feet.
methane	a colourless, odourless gas formed naturally by the decomposition of organic matter.
microscopic	so small that it can only be seen with a microscope.
midden	a mound or deposit containing shells, animal bones and other refuse that indicates the site of a human settlement.
mid-oceanic ridge	elongated rise on the ocean floor where molten rock periodically erupts, forming new oceanic crust.
midwater	a habitat in the deep sea, usually defined as the waters between the sunlit surface and the deep seafloor.
mole crab	a small crab that lives buried in sand at the ocean's edge; also called the sand crab. Mole crabs can dig very fast to escape from predators.
molt	to shed old feathers or hairs so that new ones can grow. Birds molt every year; so do elephant seals.
monitor	(verb) to check or gather information. (noun1) A person who checks or gathers information. (noun2) A screen for viewing information, such as a computer monitor.
monkfish	a fish with a wide mouth and a long, tapering body that lives on the seafloor in the same habitat as Atlantic cod.
moon snail	a species of marine snail that has a large, pale, rounded shell.
mooring	a fastener or anchor.
morphology	the scientific study of the form and structure of living organisms or the form and structure itself.
mudflat	a flat area along the coast, covered with a thick layer of mud or sand. Mudflats are usually under water at high tide.
mussel	a mollusc similar to a clam but with a narrow, dark-colour shell.
nautilus	a soft-bodied marine animal with many arms and a spiral shell. Nautiluses are related to octopuses and squid.

N
nematocyst	the small structure in a cell in various coelenterates, such as jellies, that when stimulated ejects a coiled tube that chemically paralyses its victim. It is located inside the stinging cell (cnidoblast).
net pen	a system in which fishes are enclosed in a net or cage. Water and waste pass freely into the surrounding environment. Find out more about aquaculture in the Seafood Watch Issues section.
notochord	a long, flexible rod that runs the length of the back in some kinds of animals (animals that belong to the phylum Chordata). In vertebrates, the notochord develops into part of the backbone.
nudibranch	a sea slug; member of a group of snails without shells that breathe through long, feathery gills on their backs.
nutrient	a chemical ion or compound that promotes growth or provides energy to a living organism.

O
observation	a part of the scientific process where something is noticed by using one of the five senses.
oceanic trench	deep, steep-sided depression in the ocean floor, formed when one plate of the earth's crust is pushed beneath another plate.
oceanography	the scientific study of all aspects of the physics, chemistry, geology and biology of the world's oceans.
ochre star	an extremely air tolerant sea star that lives in the intertidal zone. They are found in a variety of shades from purple to orange and brown depending on its location and the water temperature.
octopus	a soft-bodied marine animal that has eight arms covered with suction discs. Octopuses are related to squid and cuttlefishes.
omnivore	an animal that eats both plants and animals.
opaleye	an oval-shaped fish with blue eyes that lives in nearshore waters along the Pacific coast of North America.
opportunist	an animal that eats almost any plant or animal that comes its way.
oral-arm	dangling structures a jelly uses to transfer food from its tentacles to its mouth; also called a palp.
orange roughy	a bright orange fish that lives in the deep sea near Australia and New Zealand. Orange roughy grow very slowly—the orange roughy sold for people to eat may be 50 to 80 years old.
orca	a black and white whale that hunts in packs; also called the killer whale. Orcas are actually the largest member of the dolphin family.
order	in biology, 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). Order is the category that ranks below a class and above a family.
organic	from a living thing or organism; originating in nature rather than being made artificially.
organism	a living thing—a plant, animal, bacterium or other life form.
overfished	to consider a fish population too low to ensure safe reproduction, based on a preset limit by scientists. Find out more about overfishing and other concerns in the Seafood Watch Issues section.
overfishing	catching fish faster than they can reproduce to maintain healthy population levels. Find out more about overfishing and other concerns in the Seafood Watch Issues section.
oxygen	a colourless, odourless, tasteless gas. Most life on Earth requires oxygen to live. Animals breathe oxygen out of the air or water. Plants also need oxygen for respiration, and they produce oxygen by photosynthesis.
oxygen minimum layer	a zone in the deep sea, usually around depths of 2,000 to 2,950 feet (600-900 meters) where oxygen reaches its lowest level. A special community of organisms is adapted to live in this habitat.

P
palp	another word for oral-arm.
parasite	a plant or animal that lives in or on another plant or animal and obtains nourishment from it.
parrotfish	a coral reef fish with a strong beak for crunching coral.
pectoral	at the shoulders. The first pair of fins behind a fish's head are called pectoral fins.
pelagic	refers to fishes and animals that live in the open sea, away from the coast or seafloor.
pelagic trawling	a cone-shaped net are dragged through the mid-water column. It is often used to catch schools of small fishes such as anchovies and shrimp.
pelvic	at the hips. The pair of fins at the back of a fish's body are called pelvic fins.
perch	a name for a fish with a rounded body; the common name of "perch" is given to many different and unrelated species of fishes around the world.
pH	a measurement of how much acid is in a substance.
photic zone	the upper sunlit ocean layers to 350 feet deep (107 meters), also called the epipelagic zone.
photophore	a body organ that makes light.
photosynthesis	the process by which green plants use energy from sunlight to produce sugar and oxygen from carbon dioxide and water. The plants capture the sun's energy with the green chemical chlorophyll.
phylum	in biology, 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). Phylum is the category that ranks below a kingdom and above a class.
phytoplankton	tiny, floating plants and other kinds of microscopic green organisms that drift with ocean currents and use the sun's energy to make food.
pickleweed	a small terrestrial plant that lives close to the sea; it can grow in salty soil that would kill most other land plants.
piling	long, heavy timber or beam that supports a wharf or bridge.
pinniped	a member of the group of sea mammals that includes seals, sea lions and walruses.
pipefish	a small, slender fish, related to seahorses.
planktivore	an animal that eats plankton.
plankton	plants and animals (mostly tiny) that swim weakly, or not at all, and drift with ocean currents. Plankton are an important food source for many organisms that live in the sea.
plate	in geology, a big piece of the earth's crust. The earth's crust is broken into many plates, which move very slowly as they float on molten rock deep below. Where plates meet, they bump and jostle, giving rise to earthquakes. When one plate is pushed beneath another, mountains, trenches and volcanoes form.
plumage	the feathers of a bird.
poaching	illegal hunting and fishing.
pod	a pod of marine mammals is a group of animals traveling together.
pollock	a fish related to cod, heavily fished by people for food. Pollock are made into fish sticks and imitation crab meat.
pollution	degradation of the natural environment by chemicals, oil, trash or other substances.
polyp	a young jelly that results from the joining of sperm and egg; a polyp attaches to a surface and produces identical copies of itself or ephyra. Any sea animal with a fleshy stalk and a crown of tentacles; coral animals are polyps and so are sea anemones.
porpoise	a member of a group of small whales that have spade-shaped teeth and rounded snouts.
pot	submerged baited wire or wood cages used to attract fishes and hold them alive until the fisherman returns to haul up the gear.
prawn	a shrimp or shrimplike crustacean.
predator	an animal that kills and eats other animals.
preen	to groom and arrange feathers. A bird preens its feathers to keep them clean and in good working order.
prey	an animal that is killed and eaten by a predator.
process	a series of actions that bring about a result. Scientific process involves making observations, formulating hypotheses, designing and conducting experiments, collecting data, analyzing results, drawing conclusions and sharing findings with others.
producers	life forms (plants, diatoms, some bacteria) that produce their own food from simple, non-living chemicals. Producers are the basis of all food chains.
protein	a large group of organic compounds that most organisms use in the construction of their bodies. Muscle, skin and many other kinds of living tissue are made at least partly of protein. Many animals need protein in their diet.
pufferfish	a small fish that puffs into a ball when threatened.
purse seining	encircling and catching large schools of fishes with a fishing net. The net pulls shut at the top and bottom and looks like a bag or purse.

Q
QuickTime	computer software that makes it possible to view movies, video clips, animations and other special media from a web page.
quintessential	ultimate; the finest example of something.

R
raceway	a method used for fish farming in which fish are enclosed in a channel system with a continuous source of fresh water flowing through the system. Waste can be captured and treated in a raceway.
radula	a rough tongue or band of horny teeth used by snails and other molluscs to scrape algae or bore into shells.
Rathbunaster	a deep sea star with many arms that dwells on the seafloor.
raucous	loud and noisy.
ray	a fish related to sharks and skates, which bears live young and has a cartilaginous skeleton, a broad flat body and a blunt snout.
raze	to destroy or tear down.
recirculating system	a method used for fish farming where fish are enclosed in tanks where water is treated and recirculated through a complex system of filters and where waste can be captured and treated. Find out more about aquaculture in the Seafood Watch Issues section.
red snapper	a fish with red sides, popular with people as a food fish. Many red snapper are caught in the Gulf of Mexico. The name "red snapper" is sometimes given to other, unrelated species of fishes, such as Pacific rockfish.
reef	an underwater structure; something that extends up from the seafloor but does not rise above the surface of the water like an island. Coral reefs are formed from the hard skeletons of coral. There are also rocky reefs, which are piles of rock under water.
reference	(noun) a source of information; (verb) to identify and record a source of information.
refuge	a safe place.
rehabilitate	to restore to health or wholeness.
research	scientific study to find out facts, test models and develop theories about the natural world.
ribbon eel	a fish in the moray eel family, with a long slender body and large feathery nostrils.
rockfish	a big, wide-bodied fish, which lives for many years and generally produces only a few young per year. More than 60 species of rockfishes live along the Pacific coast of North America.
rockhopper trawl	a type of trawl net equipped with tires or rollers that let the net roll over rocky areas on the seafloor. Rockhopper trawls are very destructive to the seafloor habitat.
root stabilized	held together or held in place by the roots of plants.
ROV	a remotely operated vehicle that dives in deep water to videotape or collect deep sea animals or other scientific data. An ROV doesn't carry people—it's operated from a research ship at the ocean's surface.
ruddy duck	a species of small duck that lives in coastal areas. Ruddy ducks have stiff tail feathers that serve as a rudder. Males have a long bill that is black—except during breeding season—then it turns blue. With black heads and white cheek patches, male ruddy ducks have chestnut bodies. Females have a dark grayish-brown head, pale cheeks and a gray body.
ruddy turnstone	a shorebird with short legs and a reddish-brown back. Turnstones flip over stones to find small invertebrates to eat.

runoff	polluted water that runs from the land or escapes from a pond into a larger body of water.

S
sablefish	a long-bodied Pacific fish with dark skin and oily flesh. Adults live in very deep water.
salinity	the saltiness of 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 star	a species of sea star that lives on the sandy seafloor.
sanddab	a type of small flatfish, caught for food along the California coast. There are several species of sanddabs.
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.
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 eats dead plants or animals or their parts.
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 fan	a member of a group of corals that form delicate, fan-shaped skeletons.
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 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.
seal	a member of a group of marine mammals that have fur, blubber and no visible earlobes on the sides of their heads. Seals are graceful swimmers, but move only clumsily on land.
seaweed	any of the large plants that grow in the sea, especially marine algae like kelp.
sediment	particles of sand, mud or clay. Layers of sediment often cover the bottom of a body of water.
sensor	a device that receives and responds to a signal or stimulus.
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	sitting still; staying in one place. Sessile marine animals are attached at the base and sit in one place on rocks or canyon walls.
sexual dimorphism	a distinct difference in appearance between males and females of the same species.
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.
shellfish culture	a process in which oysters, clams and mussels are grown on beaches or suspended in seawater by ropes, plastic trays or mesh bags. Because they are filter feeders they require clean water to thrive, and because supplemental feed is not used, there is relatively little waste produced.
shore crab	a small crab that lives and feeds along the seashore. There are several species of shore crabs.
shorebird	a bird adapted to live and find food along the seashore.
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	very tiny particles of mud, sand or clay.
siltation	the process of being covered with a layer of fine mud, silt or sand.
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.
slough	a small, muddy marshland or tidal waterway which usually connects other tidal areas.
smack	gathering or group of jellies, pushed together by strong winds and currents.
smelt	small, schooling fishes. 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.
sole	a fish with a flattened body adapted for life on the seafloor; a flatfish.
sonar	a system that uses transmitted and reflected sound waves to find objects under water.
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 colour 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.
spicule	a small, needle like structure of silicate or calcium carbonate supporting the soft tissue of certain invertebrates like sponges.
spinner dolphin	a species of small dolphin, which often spins in the air when it leaps.
sponge	an invertebrate with a very simple body that spends its life in one place. Some sponges 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.
spotted dolphin	a species of dolphin with spotted skin. Spotted dolphins have no spots when they are born. As they become adults, the first greyish white spots begin to appear.
squarespot	a small, colourful fish that lives in 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.
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 stemlike part of a kelp plant connecting the holdfast to the fronds.
stock	fish population—the total number of fishes of each species.
stranded	washed up on shore.
subduction	the process in which one huge plate of the earth's crust descends beneath another plate.
submarine canyon	a long, narrow, steep-walled undersea valley.
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.
sulfide	a compound of sulfur.
sulfur	a pale yellow, nonmetallic chemical element. Sulfur compounds often have a strong smell, like rotten eggs.
surf zone	the area of rough water next to the land, where ocean waves hit the shore.
surfperch	a fish with rounded bodies that lives close to shore and feeds in the rough water of the surf zone.
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.
swarm	gathering or group of jellies, pushed together by strong winds and currents.
swimbladder	a gas- or oil-filled sac found in many fishes. A swimbladder is like a float; without it, the fishes 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. Swordfishes are famous for their speed and strength. They're also heavily fished for their meat.
symbiosis	The relationship of two or more different organisms in a close association that may be but is not necessarily of benefit to each.

T
tentacle	long, slender, flowing part of a jelly that contains stinging cells.
terrestrial	of the land; living on land.
tether	a long rope or leash that attaches two things together. The cable that attaches a submersible to a ship is called a tether.
thermocline	a zone where the temperature drops rapidly as you descend deeper into the water.
thorax	the chest region of a vertebrate animal, or the central segment of the body of an insect, crustacean or other arthropod.
tidal channel	a channel where water rises and falls with the tides.
tide	the daily rise and fall of sea level along a shore, caused by the pull of the moon and the sun on Earth's oceans.
tide pool	a pool of water left along the shore as the tide level falls.
tilapia	a member of a group of plant-eating, freshwater fishes native to Africa; they are easily raised in ponds.
transect	an area of land or seafloor sectioned off for particular study purposes, usually in the form of a long, continuous strip.
transformer	a device used to transfer electric energy from one circuit to another.
transparent	able to be seen through.
trap	submerged baited wire or wood cages used to attract fishes and hold them alive until the fisherman returns to haul up the gear.
trawl	a funnel-shaped net towed through the ocean or along the seafloor to collect fishes and invertebrates.
trawler	a fishing boat that tows a trawl net.
trawling	dragging a trawl net through the water or along the seafloor.
trolling	pulling fishing lines, from rods hooked and baited, behind a boat. Fishermen use a variety of lures and baits for different types of fishes.
trout	a member of a group of long-bodied fishes related to salmon. Trout have been important food fish for people for centuries. Many trout species live their entire lives in fresh water, but some spend part of their lives in the sea and return to rivers to spawn.
tubeworm	any of a number of species of marine worms or wormlike animals that make a chimney like tube to live in. In some species, the tubes are leathery, in others hard and stony.
tuna	a group of large, sleek, predatory fishes that wander the open oceans of the world. Many species of tuna are important food fish for people.
tunicate	small, primitive chordate animals that live attached to rocks or to the seafloor. Many species of tunicate live in the intertidal zone, and some, like the predatory tunicate, live in the deep sea. Some tunicates are called "sea squirts" because they squirt water when disturbed.
turbidity currents	a quick-moving mixture of water and sediments that travels downslope, scouring the substrate and depositing sediments as it goes.
twilight zone	in the ocean, the midwater zone of dim light that lies between the sunlit zone and the completely dark, deeper zone.

U
understory	the vegetation that grows below the canopy of a forest.
upwelling	the movement of cold, nutrient-rich water from the ocean depths up toward the ocean surface.
urchin	a type of echinoderm invertebrate, related to sea stars, shaped like a ball and protected by long, sharp spines. Often called a "sea urchin."

V
vegetarian	an animal that eats only plants (see herbivore).
vegetation	plants.
ventral	on or toward the belly or underside (opposite of dorsal).
vertebrate	an animal with a backbone. Fishes and people are both vertebrates.
vertical	up-and-down; in the up-and-down direction (opposite of horizontal).
vertical migration	an aquatic animal's daily or seasonal movement up toward the water's surface and back down to deeper water.
vestigial	non-functioning, a remnant of a body part that existed in a former species of an animal. Whales have tiny, vestigial hind legs buried deep in their bodies.
volcano limpet	a large limpet with a volcano-shaped shell; it prefers warm waters.

wahoo	a large fish that lives in the open ocean in warm parts of the Pacific.

W
wetlands	a place where the soil is very wet and the habitat is part land, part water. Salt marshes, freshwater and brackish marshes, shallow lagoons, sloughs, tidal mudflats, swamps, bogs and fens (peat-forming areas) are different types of wetlands. Wetlands play a critical role for both wildlife and humans. They serve as vital feeding, nesting and resting sites for migratory birds. Many marine fish use coastal wetlands as nurseries for their young. Wetlands also act as buffers against storm waters, while serving as natural purifiers of wastewater.
whale	a large sea mammal that has smooth skin and breathes through a blowhole located on top of its head. The toothed whales, including sperm whales, orcas, dolphins and porpoises, have sharp teeth for catching fishes. The baleen whales, including the blue whale, grey whale and humpback, have flexible baleen fringes in their mouths for eating krill.
*wharf (pl.* wharves)**	a structure built out over the water where boats can dock. A wharf is supported by heavy wooden or concrete pilings.
wobbegong	a coral-reef shark from Australia and the south Pacific, with spotted skin that makes it almost invisible among the coral.
wolf-eel	a long, eel-shaped fish with large teeth, most common in northern Pacific waters.

Y
yellowfin tuna	one of the larger species of tuna, which has yellow markings on its fins and tail. Yellowfin live in warm, tropical waters. Much of the world's canned tuna is yellowfin.

Z
zonation	the distribution of the plants and animals in a community into recognizable zones.
zooplankton	animal plankton.
*zooxanthellae (sing.* zooxanthella)**	tiny, colourful algae that live in the tissues of coral. They use the energy from sunlight to produce nutrients, which they share with the coral.

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