Resources
Glossary of Terms
Aquaculture Refers to growing marine or freshwater animals and aquatic plants (often called “fish farming”). Aquaculture may take place in the open ocean, allowing exchange of water and organisms between farms and ecosystems, or may be undertaken in closed-tank systems.
Blast-fishing Use of some form of explosive, usually on coral reefs, to facilitate the capture of dead or stunned fish. Blast-fishing, also known as dynamite-fishing, shatters reef structures.
Bycatch Animals caught by accident in fishing gear; species that fishers do not intend to catch. Bycatch is usually thrown back dead or injured. An alternative term for bycatch is bykill which acknowledges that captured species are not targeted as “catch” and often die.
Cyanide fishing Fishers inject a sodium cyanide solution into reef crevices or around coral heads to stun live fish or invertebrates for capture; these fish are sold either in the live-reef fish trade (mainly in Asia) or as ornamental display (mainly in North America, the European Union and Japan). Cyanide also affects untargeted fish, invertebrates and the surrounding reef.
Demersal Organisms found at or near the bottom of the sea or a lake.
Dragger (Trawler) A term used in Eastern Canada for a trawler which is a fishing boat that drags its fishing gear across the bottom, often leaving a wide path of disturbed or destroyed habitat called a “trawl scar”. In Canada, groundfish such as cod, haddock, lingcod, rockfish, sole and flounder are caught with otter trawls. Otter trawl nets are large purse-shaped nets with mouths kept open by top-side floats and weighted rollers on the bottom. Fish accumulate at the end of the net called the codend.
Driftnets Driftnets are large floating gill nets, made of nylon mesh measuring between 2km and 150 km in length, and between 2.5 and 4.5 m in depth that are left to “drift” in the ocean for periods of eight hours or more. These nets are suspended by floats and are also known as pelagic gillnets. In 1989, the United Nations introduced resolutions asking for states party to the United Nations Convention on the Law of the Seas (UNCLOS) to voluntarily abandon the use of driftnets on the high seas. The 1991 resolution asked for implementation by June 30, 1992. Driftnets are condemned for their bycatch of large, air-breathing, long-lived or vulnerable marine life including northern right whale dolphins, sperm whales, dolphins, seabirds, blue sharks and leatherback turtles, among others. Driftnet fishing is still practiced illegally and is well documented in Mediterranean waters (also see ghost nets).
Exclusive Economic Zone A country’s exclusive economic zone (EEZ) is the seazone in which it has rights to the exploration and use of marine resource. EEZ’s extends 200 nautical miles or 370 km offshore, but do not technically include Territorial waters, which are the narrow strip of seazone extending from shore to 12 nautical miles offshore. EEZ’s may extend less than 200 miles if the resulting point would be closer to another country than to the country in question. EEZ are defined under the 1982 United Nations Convention on the Law of the Sea , Part V, Article 55.
“The Exclusive Economic Zone is an area beyond and adjacent to the territorial sea, subject to the specific legal regime established in this Part, under which the rights and jurisdiction of the coastal State and the rights and freedoms of other States are governed by the relevant provisions of this Convention.”
Feed Conversion Ratio (FCR) Ratio that describes the number of kilograms of fish feed that are used to produce one kilogram of whole fish. A biological FCR refers to the net amount of feed used to produce one kilo of fish. Economic FCRs take into account all of the feed used and includes the food not eaten, as well as feed given to fish that die prior to harvest. The FCR does not evaluate the total amount of wild fish required to make the feed, which is a critical environmental consideration.
Fishmonger A person who sells fish as their livelihood.
Ghost nets Drift nets that are either lost accidentally or intentionally discarded by fishing boats. Once detached from boats, they may spend years entangling and killing fish, turtles, seabirds and whales. Other types of gear can also ghost-fish by killing marine life when they are not being used for fishing.
Gillnet Gillnets capture fish by entangling them in the netting, often by the gills. These nets can be used either alone or, more often, in large numbers placed in a line to make a ‘fleet’ of nets. Depending on their design these nets may be used to fish on the surface, in mid-water or on the ocean bottom.
High Seas Ocean waters outside of national jurisdiction, or outside Exclusive Economic Zones (insert HL), also referred to as Mare liberum.
Highly migratory fish stocks Highly migratory fish stocks roam over large distances and may be found in numerous Exclusive Economic Zone jurisdictions and the high seas. Highly Migratory Species are defined by a listing in Annex 1 of the 1982 United Nations Convention on the Law of the Seas.
Longlines A longline is made up of a main fishing line with secondary lines branching off of it, each with a hook. Longlining may happen at the surface, in mid-water or close to the bottom. Lines vary in length. A Canadian bottom longline may be ~40-50 metres in length, whereas pelagic longlines used in international waters can be up to 100km long. Longlines are used on the high seas, as well as in waters controlled by Canada, the United States, South America, Australia, New Zealand and countries in southern Africa. Longlining targets fishes such as tuna, swordfish and Patagonian toothfish, but often results in bycatch of turtles, sharks and albatross, among other species. Some bottom longlining has low bycatch and may be a feasible alternative to dragging.
Non-target species Fishes that are not the primary target of a fishery, are unintentionally caught, but are also known and expected to be part of captures. These fish may still have market value and be retained, or may be thrown back as discards.
Pelagic Is the area including the entire open ocean comprising the water column except areas near the coast or the sea bottom.
Pole and line fishing (Poling) Also called pole-and-live-bait fishing, this method of fishing involves attracting schools of fish to the vessel with live or dead bait or by spraying the water’s surface to stimulate the behaviour of small fish: these attract larger fish.
Purse seines Large nets that are pulled around a group of fish by boats and then drawn closed, or pursed, at the bottom to prevent fish from diving to escape. This method is used to catch Alaskan salmon, herring and tuna.
Seafood Food from the sea that usually includes sea water animals, such as fish and shellfish (including molluscs, and crustaceans). In North America, the term seafood is also applied to similar animals from freshwater.
Seine net These nets are usually set from a boat. They can be operated either from the shore (beach seines) or from the boat itself (e.g., Danish or Scottish seines). The manner of capture is to surround an area of water with a very long net. The net is then hauled in using two ropes fixed to the ends of the net.
Shifting baselines A baseline is a description of the original, or an earlier, state of a situation. In oceans, current health and abundance data are compared to the baseline to determine if things are getting better or worse. The “shifting baseline syndrome” refers to the changing reference points used by successive generations against which each compares the present. Comparison with only recent history allows each generation to consider a different set of conditions as “normal”, “natural” or “wild”, often impeding our understanding of the true magnitude of environmental degradation.
Straddling fish stocks Fish populations or stocks that straddle the boundary of a State’s Exclusive Economic Zone (EEZ) and the high seas (some stocks straddle ‘out’ of an EEZ while others straddle ‘into’ an EEZ) while highly migratory fish stocks are those that generally roam over large distances and may be found in numerous EEZ jurisdictions and the high seas.
Subsidies A range of government interventions, usually financial, given to allow fishing to continue when it would not otherwise be economically viable.
Sustainable seafood Fish that are caught or farmed with consideration for the long-term viability of individual marine species and for the oceans’ ecological balance as a whole.
Tonging Hand tongs are two rakes with wire baskets attached to twenty foot long wooden shafts with a pin about one third of the way up from the rakes which makes them act like scissors. Tongs are used to harvest oysters where the oysterman stands up on the washboards (sides of boat) opening and closing the shafts of the tongs until the basket is full, then hand over hand brings the tongs to the top and while balancing himself, dumps the oysters and shells on the cull board. The culler then sorts out the oysters and puts the legal size oysters in the boat and releases the undersized oysters over the side to settle back down on the oyster bed.
Transboundary stocks A group of commercially exploitable organisms, distributed over, or migrating across, the maritime boundary between two or more national jurisdictions, or the maritime boundary of a national jurisdiction and the adjacent high seas, whose exploitation can only be managed effectively by cooperation between the States concerned.
Trawling The use of large nets that are dragged through some portion of the water column or along the sea floor to capture marine organisms. Bottom trawls scrape the ocean bottom to harvest marine organisms. Mid-water trawls only occasionally come in contact with the bottom and are used to harvest free-swimming animals from the water column (e.g., hake, squid).
Trolling Not to be confused with trawling, trolling drags baited hooks or lures through the water by means of a fishing rod or other pole, extended from fishing boats on stiff rods. Trollers control the depth of lines by their speed and/or fixed weights. Trolling is used to capture some types of tuna and salmon as well as freshwater game fish.
Trap fishing Fishing by means of using pots or cages designed to capture aquatic animals alive (e.g., crab pots, shrimp pots).
Trash fish Fishing industry term, referring to fish captured incidentally or as bycatch. Usually discarded or considered to be of little worth. As we deplete our oceans, fish that used to be known as trash fish often become consumer products (e.g. Sardines)
Turtle exclusion device (TED) A modification to shrimp trawl nets that allow turtles to escape.
