Glossary of Fishery Terms - C

C

• Carapace - a calcified protective cover on the upper frontal surface of crustaceans. It is particularly well developed in lobsters and crabs.

• Carrying capacity - the supportable population of a species, given the food, habitat conditions and other resources available within a fishery.

• Catadromous - fish that live their adult lives in fresh water lakes or rivers but migrate down rivers to spawn in the sea. An example are freshwater eels of genus Anguilla, whose larvae drift on the open ocean, sometimes for months or years, before travelling thousands of kilometres back to their original rivers (see eel life history). Fish that migrate in the opposite direction are called anadromous.

• Cephalopods - (from the Greek for "head-feet") animals such as squid and octopus where tentacles converge at the head. Cephalopods are the most intelligent of the invertebrates with well-developed senses and large brains.

• Cetacean - member of the group of marine mammals that includes whales, dolphins and porpoises. They are the mammals most fully adapted to aquatic life and are noted for their high intelligence.

• Cetacean bycatch - the incidental capture of non-target cetacean species by fisheries. Bycatch can be caused by entanglement in fishing nets and lines, or direct capture by hooks or in trawl nets.

• Climate change - variation in the Earth's global climate or in regional climates over time. Climate change involves changes in the variability or average state of the atmosphere over time periods ranging from decades to millions of years. These changes can be caused by natural processes on Earth, external factors including variations in sunlight intensity, and more recently by human activities.

• cohort - those individuals of a stock born in the same spawning season. For annual spawners, a year's recruitment of new individuals to a stock is a single cohort or year-class. See brood.

• Commercial fishery - An umbrella term covering fisheries resources and the whole process of catching and marketing fish, molluscs and crustaceans. It includes the fishermen and their boats, and all activities and resources involved in harvesting, processing, and selling.

• Conspecific - organisms or populations that belong to the same species. Organisms that don't belong to the same species are heterospecific.

• Continental margin - the zone of the ocean floor that separates the thin oceanic crust from the thick continental crust. Continental margins constitute about 28% of the oceanic area.

• Continental rise - is below the slope, but landward of the abyssal plains. Extending as far as 500 kilometres from the slope, it consists of thick sediments which have cascaded down the slope and accumulated as a pile at the base of the slope.

• Continental shelf - the seabed from the shore to the edge of the continental slope, covered by relatively shallow seas (known as shelf seas) and gulfs.

• Continental slope - the slope which starts, usually abruptly at about a 200 metre depth, at the outer edge of the continent shelf and dips more steeply down to the deep-ocean floor (abyssal plain).

• Coriolis effect - due to the Earth's rotation, freely moving objects on the surface of the earth veer right in the northern hemisphere and left in the southern hemisphere. This effect is called the Coriolis effect, and works, in particular, on winds and ocean currents. The effect varies with latitude and is zero at the equator and increases towards the poles.

• Cottage industry - small, locally owned businesses usually associated in fishing with traditional methods and low relative yield.

• Crab pot fishery - a fishing technique where crabs are lured by bait into portable traps, sometimes called pots.

• Crustaceans - A group of freshwater and saltwater animals having no backbone, with jointed legs and a hard shell made of chitin. Includes crabs, lobsters, crayfish, shrimp and krill.