Fisheries Glossary - Voices of the Bay

This glossary of fisheries terms from terms frequently used in fisheries as well as terms that appear in the Fish & Fishery Fact pages and the Voices of the Bay Fisheries Education Curriculum.

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Abyssal Plain
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000-6,000 meters.

Abyssopelagic
The very deep benthic communities near the bottom of oceans, at depths of 4,000-6,000 meters (13,123 to 19,685 feet); this zone remains in perpetual darkness and never receives daylight.

Aft
Toward the stern of a boat.

Alevin
A young fish, especially the newly hatched salmon when still attached to its yolk sack.

Algae
A large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length.

Allocation
Distribution of fishing opportunity among user groups or individuals. Shares are sometimes based on historic amounts.

Anadromous Species
Fish that migrate from saltwater to freshwater to spawn.

Angler
A person catching fish or shellfish with no intent to sell, which includes people engaged in catch-and-release fishing.

Aphotic
The portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1% of sunlight penetrates.

Aquaculture
The raising of fish or shellfish under some controls. Feed and ponds, pens, tanks, or other containers may be used.

Bag Limit
The number and/or size of a species that a person can legally take in a day or trip. This may or may not be the same as a possession limit.

Barbed Hooks
The hooks used in hook & line fishing that has a barb at the end to help retain the fish on the hook.

Barbless Hooks
The hooks used in hook & line fishing that no longer have a barb at the end to allow the fish to easily be removed from the hook.

Bathymetry
Information on depths in the ocean. Often showed in a map or illustration.

Bathypelagic
The region of the ocean that extends from 1,000-4,000 meters below the ocean surface.

Beam
The boat's width at its widest point.

Beam
Trawl A conical-shaped net held open by a horizontal beam; At each end of the beam are iron frameworks that hold the net open in a vertical direction.

Benthic
Of, relating to, or occupying at the bottom of a body of water (including the ocean).

Best Available Science (BAS)
The term "best-available science" comes from the second National Standard listed in the Magnuson-Stevens Act and is the informational standard mandated for decision making.

Biogeography
The study of the distribution of species (biology), organisms, and ecosystems in space and through geological time.

Biomass
The total weight or volume of a species in a given area.

Bioregions
An ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem.

Block
A wood or metal shell that encloses one of more pulleys.

B_MSY
The biomass that allows maximum sustainable yield (MSY) to be taken.

Bow
The front part of the boat.

Brail Net
A small dip net used to scoop out portions of the catch from the main net and hail these portions aboard. Brail nets are used to transfer Tuna, Salmon, and Wetfish.

Bycatch
The harvest of fish or shellfish other than the species for which the fishing gear was set.

Bycatch Reduction Device (BRD)
Devices (such as finfish excluders) incorporated into fishing gear designed to reduce the take of non-target species.

Cannery The factory in which the method of preserving food in which the food contents are processed and sealed in an airtight container (canning).

Carapace A bony case or shield that covers the back of an animal (such as a Turtle, Crab, or Lobster).

Cartilaginous Cartilaginous fish such as sharks, skates, and rays are vertebrates whose internal skeleton are made entirely of cartilage and contain no ossified bone.

Carrying Capacity The greatest number of individuals of a given species that can be supported with the environment's available resources.

Cataromous Referring to fish that migrate from freshwater to saltwater to spawn.

Catch The total number or poundage of fish captured from an area over some period of time. The catch may take place in an area different from where the fish are landed. Note that catch, harvest, and landings have different definitions.

Catch Per Unit of Effort (CPUE) The quantity of fish caught (in number or weight) with one standard unit of fishing effort. CPUE is often considered an index of fish biomass (or abundance). Sometimes referred to as catch rate. CPUE may be used as a measure of economic efficiency of fishing as well as an index of fish abundance.

Catch Share Program A program that allocates a specific portion of the annual catch limit of a fish stock to entities such as fishermen, cooperatives, and communities.

Charter Boat A boat available for hire, normally by a group of people for a short period of time. Anglers are more likely to hire a charter boat.

Circle Hooks A type of fishhook that is sharply curved back in a circular shape. Since the circle hook catches the fish on the lips at the corner of its mouth, it greatly decreases the mortality rates of released fish as compared to J-hook that is swallowed by the fish causing it to set in the gills or vital organs.

Coastal Pelagic Species (CPS) Species that live in the water column, between the surface and 1,000 meters deep (e.g., Northern Anchovy, Market Squid, Pacific Herring, Pacific Sardine).

Coastal Zone Management Act (CZMA) To encourage and assist states in developing coastal zone management programs, to coordinate state activities, and to safeguard the regional and national interests in the coastal zone.

Cod-end The end of a trawl net. Fish are eventually pushed into the cod-end as the net is pulled through the water.

Cohort A group of fish spawned during a given period, usually within a year.

Commercial Fishing The practice of harvesting marine or freshwater resources for commercial sale.

Commercial Extinction Species declines below a level where it is economically feasible to target as a fishery and have shown no sign of recovery, even though they are no longer targeted (e.g., Atlantic Halibut, Pacific Abalone).

Commercial Passenger Fishing Vessel (CPFV) Also called "Party Boats," a commercial operation that takes multiple anglers out to fishing grounds on one boat.

Commons Belonging to, or shared equally by two or more individuals or populations.

Common-Property Resource A term that indicates a resource owned by the public. For example, it can be fish in public waters, trees on public land, and the air. The government regulates the use of a common-property resource to ensure its future benefits.

Community An ecological unit composed of the various populations of microorganisms, plants, and animals that inhabit a particular area.

Consumer A person or organization that uses a particular product.

Continental Shelf The extended perimeter of each continent and associated coastal plain.

Continental Slope The area between the offshore shallows out to where the continental shelf dips steeply to the abyssal plain.

Controlled Access Also called limited access and limited entry. A program that restricts the persons or vessels that may participate in a fishery. License limitation and individual fishing quota programs are two forms of controlled access.

Cork
Line The top rope of a gillnet with floats attached to hold up the net underwater.

Crustacean
A group of freshwater and saltwater animals having no backbone, with jointed legs and a hard shell made of chitin (e.g., Shrimp, Crabs, Lobsters, Crayfish).

Demersal
Describes fish and animals that live near water bottoms.

Depth Sounder
A sonar depth recorder that gives a continuous graphical readout of the seafloor bottom, or objects in the water column.

Derby Fishery
A fishery of brief duration during which fishermen race to take as much catch as they can before the fishery closes.

Directed Fishery
Fishing that is directed at a certain species or group of species. This applies to both recreational and commercial fishing.

Disphotic
The portion of the water column that receives only faint filtered sunlight during the daytime. Also called the twilight zone or the mesopelagic zone. The depth of this zone depends on the clarity or murkiness of the water. On average, this zone extends from 660-3,300 feet (200 to 1,000 m).

Distributor
A business that sells, transports, and delivers goods to a retailer or other entity that then sells to the end customer. Price conscious consumers often try to avoid further mark-ups in price by purchasing directly from a distributor. Also called a wholesaler.

Dockside Buyer
A person or company, located on popular fishing docks or wharfs, that buys seafood directly from fishermen.

Downwelling
The process whereby prevailing seasonal winds create surface currents that cause surface water to sink, bringing nutrient-poor ocean surface water into an area.

Dredge
A device for scraping or sucking the seabed, used for dredging (an excavation activity or operation usually carried out at least partly underwater).

Drum Seine
Similar to a purse seine but the seine is stored on a large drum mounted at the stern. The drum is particularly successful in handling shallow nets.

Echosounder
A device that uses SONAR technology for the measurement of underwater physical and biological components.

Ecosystem
A geographically specified system of organisms, including humans, the environment, and the processes that control the dynamics of the system.

Ecosystem-Based Fisheries Management (EBFM)
An approach that takes major ecosystem components and services - both structural and functional - into account in managing fisheries. Its goal is to rebuild and sustain populations, species, biological communities, and marine ecosystems at high levels of productivity and biological diversity so as not to jeopardize a wide range or goods and services from marine ecosystems while providing food, revenues, and recreation for humans.

Ecosystem-Based Management (EBM)
A broader more comprehensive management approach that takes into account the interaction of ecological, economic, cultural, and regulatory factors impacting the overall health of an ecosystem. Specific factors may include pollution, coastal development, harvest pressure, predator/prey, and other ecological interactions, as well as nearby watershed management.

Ecosystem Function
An intrinsic ecosystem characteristic related to the set of conditions and processes whereby an ecosystem maintains its integrity. Functions include such processes as decomposition, production, nutrient cycling, and fluxes of nutrients and energy.

Ecosystem Services
The benefits people obtain from ecosystems. The include provisioning services, such as food and water; regulating services, such as flood and disease control; cultural services, such as spiritual and cultural benefits; and supporting services, such as nutrient cycling, that maintain the conditions for life on Earth.

Effort
The amount of time and fishing power used to harvest fish. Fishing power includes gear size, boat size, and horsepower.

Encircling Net
A net used to encircle the fish to catch them.

Endangered Species
A classification under the Endangered Species Act. A species is considered endangered if it is in danger of extinction throughout a significant portion of its range.

Endangered Species Act (ESA)
An act of federal law that provides for the conservation of endangered and threatened species of fish, wildlife, and plants.

Environmental Assessment (EA)
As part of the National Environmental Policy Act process, an environmental assessment is a concise public document that provides evidence and analysis for determining whether to prepare an environmental impact statement of a Finding of No Significant Impact.

Environmental Impact Statement (EIS)
As part of the National Environmental Policy Act process, an environmental impact statement is an analysis of the expected impacts resulting from the implementation of a fisheries management or development plan (or some proposed action) on the environment. EISs are required for all fishery management plans. The purpose of the EIS is to ensure the fishery management plan gives appropriate consideration to environmental values in order to prevent harm to the environment.

Epipelagic
The upper region of the sea from the surface to about 200-300 meters depth.

Escapement
The percentage of fish in a particular fishery that escapes from an inshore habitat and move offshore, where they eventually spawn.

Essential Fish Habitat (EFH)
The water and substrate within an area that is necessary for the spawning, breeding, feeding, or growth to maturity for a species.

Exploitable Biomass
The biomass that is available to a unit of fishing effort. Defined as the sum of the population biomass at age (calculated as the mean within the fishing year) multiplied by the age-specific availability to the fishery.

Eviscerate
To take out the entrails of a fish.

Exclusive Economic Zone (EEZ)
The regional from 3-200 nautical miles seaward of the 48 contiguous states, Alaska, Hawaii, and U.S.-affiliated islands. The U.S. National Marine Fisheries Service (NMFS) regulates fisheries within this area.

Ex-Vessel
Refers to activities that occur when a commercial fishing boat lands or unloads a catch. For example, the price received by a captain for the catch is an ex-vessel price.

Factory Ships
A factory ship, also known as a fish-processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish. According to the FAO, there are about 38,400 vessels greater than 100 tons in the world's factory fishing fleet.

Fathom
A nautical unit of measurement. One fathom equals 6 feet or 1.83 meters.

Federal Register
The official daily publication for Rules, Proposed Rules, and Notices of Federal agencies and organizations, as well as Executive Orders and other Presidential documents. Fisheries regulations are not considered final until they are published in the Federal Register.

Filter Feede
r An organism that feeds by capturing particles suspended in the water column. Also called suspension feeders.

Finfish
A common term to define fish as separate from shellfish.

Fishing
The catching, taking, or harvesting of fish; the attempted catching, taking, or harvesting of fish; any other activity that can reasonably be expected to result in the catching, taking, or harvesting of fish; any operations at sea in support of, or in preparation for, any of these activities.

Fish Emulsion
Fish emulsion is a fertilizer emulsion that is produced from the fluid remains of fish processed for fish oil and fishmeal industrially.

Fish Ladder
A fish ladder, also known as a fish way, fish pass, or fish steps, is a structure on or around artificial barriers (such as dams and locks) to facilitate diadromous fishes' natural migration. Most fish ladders enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps (hence the term ladder) into the waters on the other side.

Fishery
The people involved, species or type of fish, area of water, method of fishing, class of boats, purpose of the activities, or a combination of all of the above, engaged in raising or harvesting seafood.

Fishery-Dependent Data
Data about fish resources collected by sampling commercial and recreational catches.

Fishery-Independent Data
Data about fish resources collected by methods other than sampling commercial and recreational catches. An example of such a method is sampling in marine reserves.

Fishery Management Council (FMC)
A fisheries management body established by the Magnuson-Stevens Fishery Conservation & Management Act to manage fishery resources.

Fishery Management Plan (FMP)
A plan, and its amendments, that contains measures for conserving and managing specific fisheries and fish stocks.

Fishing Community
A community which is substantially dependent on or substantially engaged in the harvest or processing of fishery resources to meet social and economic needs, and includes fishing vessel owners, operators, and crew and fish processors that are based in such a community.

Fishing Industry
All the people and activities involved in the harvesting, processing, and distribution of fishery products.

Fishing Method
The wide range of gear to land the catch.

Fishing Mortality
A measurement of the rate of removal of fish from a population by fishing. Fishing mortality can be reported as either annual or instantaneous. Annual mortality is the percentage of fish dying in one year. Instantaneous is that percentage of fish dying at any one time. The acceptable rates of fishing mortality may vary from species.

Fishing Season
The timeframe in which it is legally allowed to catch fish.

Fishmeal
A commercial product made from both whole fish and the bones and offal from processed fish. It is a brown powder or cake obtained by rendering pressing the cooked whole fish or fish trimmings to remove most of the fish oil and water, and then ground. What remains is the "fishmeal". Fishmeal is a nutrient-rich and high protein supplement feed ingredient used primarily in diets for domestic animals and sometimes used as a high-quality organic fertilizer.

Fishmonger
Someone who sells fish and seafood. In some countries modern supermarkets are replacing fishmongers who operate in shops or fish markets.

Fixed Gear
Fishing gear that is stationary after it is deployed (unlike trawl or troll gear which is moving when it is actively fishing).

Flash Freezing
Flash freezing (or blast freezing) refers to the process in various industries whereby objects are quickly frozen by subjecting them to cryogenic temperatures.

Flatfish
The flatfish are an order (Pleuronectiformes) of ray-finned fish. In many species, both eyes lie on one side of the head, one or the other migrating through and around the head during development. Some species face their left side upward, some face their right side upward, and others face either side upward.

Float Line
A buoyant line with attached floats at the top of the net (gillnet or trawl net).

F_MSY
The fishing mortality rate that maximizes catch biomass in the long term.

Food Webs
A network describing the feeding interactions of the species in an area.

Foot Rope
The bottom rope extending around the mouth of a trawl net, usually weighted to hold the net on the ocean bottom.

Forage Fish
Small fish that are preyed on by larger predators for food.

Fry
Young fish, especially when it is newly hatched.

Gaff
A pole with a large hook at its end.

Ghost-Fishing
Situation when abandoned fishing gear continues to catch organisms.

Gillnet
A curtain like net suspended in the water with mesh openings large enough to permit only the heads of the fish to pass through, ensnaring them around the gills when they attempt to escape.

Groundfish
A species or group of fish that lives most of its life on or near the sea bottom.

Gurdies
Spool used in trolling upon which the fishing line is wound. The gurdies are usually powered, but on some of the smaller boats, like salmon dories, they are often hand-operated.

Gut-Hooked
When a fish is caught with a hook and is brought aboard with the hook buried in their stomach or gills.

Habitat
The place and its associated environmental conditions where an organism naturally lives, grows, and reproduces; such conditions include characteristics of the substrate, water, and biological community.

Habitat Alteration
Habitat alteration is a change, or alteration, to a particular environment.

Hadal
The oceanic zone in the deepest trenches in the ocean. This zone is found from a depth of around 6,000 meters (20,000 ft) to the bottom of the ocean.

Harvest
The total number or poundage of fish caught and kept from an area over a period of time. Note that harvest, catch and landings have different definitions.

Harvest Guideline(s)
A numerical harvest level that is a general objective, but not a quota. Attainment of a harvest guideline does not require a management response, but it does prompt review of the fishery.

Harvest
Specifications The detailed regulations that make up management measures - for example, trawl footrope size, depth limits, net mesh size, etc.

Hatchery
A facility where fish eggs are hatched and the fry raised, especially to stock lakes, streams, and ponds.

Haulback
The period in fishing operations during which the gear is hauled from the water back onto the fishing vessel.

Head Rope
The top rope extending around the mouth of a trawl net, to which floats are attached to keep the net mouth open vertically.

Herbivores
Organisms that are anatomically and physiologically adapted to eat plant-based foods.

High Grade
The act of discarding lower-quality or lower value fish in favor of retaining better fish.

High Seas
All waters beyond the exclusive economic zone (3-200 miles) of the U.S. and beyond any foreign nation's exclusive economic zone.

Highly Migratory Species (HMS)
Species that have a wide geographic distribution, both inside and outside of nations' EEZ, that undertake migrations of significant but variable distances across oceans for feeding and reproduction, and that live predominately in the open ocean (e.g., Tuna, Sharks, Billfish, Swordfish).

Hook & Line Gear
A fishing method that catches fish by means of a series of baited hooks, which are suspended on lines into the ocean. For example, horizontal longlines, vertical setlines, trolling, and jigging.

Hull
The watertight body of a ship or boat.

Incidental Catch
(Species) Species caught when fishing for the primary purpose of catching a different species.

Incidental Take
The "take" of protected species (such as listed salmon, marine mammals, sea turtles, or sea birds) during fishing. "Take" is defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.

Individual Bycatch Quota (IBQs)
A type of quota used to control the catch of prohibited species.

Individual Fishing Quotas (IFQs)
A type of quota (a part of a total allowable catch) allocated to individual fishermen, vessel owners, or processors and which can be transferred (sold or leased) to others.

Individual Transferable Quota (ITQs)
A type of quota (a part of the total allowable catch) allocated to individual fishermen or vessel owners and which can be transferred (sold or leased) to others.

Inland Waters
All of the waterways on land. The inland waterways of the United States include over 25,000 miles (40,000 km) of navigable waters. Almost all of the navigable rivers and canals in the United States are in the eastern half of the country.

Inseason Adjustments
Regulatory changes that affect an ongoing fishery.

Integrated Ecosystem Assessment (IEA)
A synthesis and quantitative analysis of information on relevant physical, chemical, ecological, and human processes in relation to specified ecosystem management objectives.

J-Hooks
A traditional hook in the shape of the letter "J" that is used in hook & line fisheries.

Jig
An artificial lure made to simulate live bait. It is usually made with a lead head cast on a single hook and is heavier than most other lures.

Juvenile
A young fish or animal that has not reached sexual maturity.

Knot
A nautical unit of speed. One knot equals 1 nautical mile per hour (approximately 51 centimeters per second).

Lampara Net
An encircling net (similar to purse seine yet that does not close completely) used in shallow water.

Landing
The amount of fish (usually in pounds though sometimes as number of fish) caught be fishermen and delivered at the docks, then sold for profit or kept for personal consumption. Landings are reported at the points at which fish are brought to shore. Note that harvest, catch, and landings have different definitions.

Larvae
A distinct juvenile form many animals undergo before metamorphosis into adults.

Leader
A length of monofilament or wire that connects the main fishing line to the hook used for capturing fish.

Lead Line
The bottom rope on a gillnet or trawl net, which is weighted. The floats on the cork line and the weights on the lead line act to hold the net open vertically underwater.

Limited Access Privilege Program (LAPP)
A catch share program whereby quotas (a portion of the total allowable catch of the fishery) may be received or held for exclusive use by a person, business, or other entity.

Limited Entry
A program that changes a common property resource like fish into private property for individual fishermen (e.g., license limitation, individual transferable quotas).

Longline
Fishing gear made up of a long main line attached to which are a large number of short branch lines. At the end of each branch line is a baited hook. When catching groundfish, longlines are laid on the seafloor. When catching fish in the water column, the longlines are buoyed near the surface. Longlines can be 20+ miles long. They are also called setlines.

Long-Term Potential Yield (LTPY)
The maximum long-term average yield that can be achieved through conscientious stewardship, by controlling the proportion of the population removed by harvesting and regulating fishing effort of total catch levels.

Management
The art of taking actions that affect a resource and its exploitation with a view to achieve certain objectives, such as maximizing the production of that resource (e.g., fishery regulations such as catch quotas or closed seasons). Managers are those who practice management.

Management Authority
The legal entity that has been assigned by a state or states with a mandate to perform certain specified management functions in relation to a fishery, or an area (e.g., coastal zone).

Mantle
A significant part of the anatomy of mollusks: it is the dorsal body wall that covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.

Mariculture
A specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean or an enclosed section of the ocean (e.g., Prawns, Oysters, Seaweed, Abalone).

Marine Mammal Protection Act (MMPA)
Prohibits the harvest or harassment of marine mammals, although permits for incidental take of marine mammals while commercial fishing may be issued subject to regulation.

Marine Protected Area (MPA)
Any area of the marine environment that has been reserved by federal, state, territorial, tribal, or local laws or regulations to provide lasting protection for part or all of the natural and cultural resources therein.

Marine Spatial Planning (MSP)
Zoning areas of the ocean for specified activities to prevent user conflict and reduce impacts of the activities.

Market Economy
An economy that operates by voluntary exchange in a free market and is not planned or controlled by a central authority; a capitalist economy.

Maximum Sustainable Yield (MSY)
The largest average catch that can be taken continuously (sustained) from a stock under average environmental conditions.

Mesopelagic
A somewhat arbitrary depth zone in offshore or oceanic waters, usually below 600 feet and above 3,000 feet (200-1,000 meters)

Metric Ton
2,200 pounds.

Mixed Stock Exception
In "mixed-stock complexes," many species of fish swim together and are caught together. This becomes a problem when some of these stocks are healthy and some are overfished because even a sustainable harvest of the healthy stock can harm the depleted stock. In order to avoid having to shut down all fisheries to protect one particular overfished stock, the national standard guidelines allow a "mixed-stock" exception to the "overfished" definition. This would allow higher catches of some overfished species than ordinarily allowed in order to avoid severe hardship to fishing communities.

Mollusks
A group of freshwater and saltwater animals with no skeleton and usually one or two hard shells made of calcium carbonate (e.g., oysters, clams, mussels, conchs, scallops, squid, octopus).

Mooching
A method of salmon fishing from a drifting or propelled boat. The bait is sunk deep with a heavy sinker then brought upward at an angle as the boat is maneuvered forward a few yards or the line retrieved. The bait is then allowed to sink once again to the bottom and the procedure repeated.

Mud Gear
Rubber disks strung on wire rope that is attached to the footrope of a trawl net. The purpose of the mud gear is to stir up the bottom and herd the fish into the net. Also called a tickle chain.

National Environmental Policy Act (NEPA)
Requires Federal agencies to consider the environment when making decisions regarding their programs. Section 102(2)(C) requires Federal agencies to prepare an Environmental Impact Statement before taking major Federal actions that may significantly affect the quality of the human environment.

National Standards
A set of 10 conservation and management standards included in the Magnuson-Stevens Act. Each fishery management plan must be consistent with all 10 nautical standards.

National Standard Guidelines
Guidelines issued by the National Marine Fisheries Service to provide comprehensive guidance for the development of fishery management plans and amendments that comply with the national standards of the Magnuson-Stevens Act. These guidelines are found in Title 50, Code of Federal Regulations, part 600.

Nautical Mile
Nautical miles are used on ocean and coastal waters. Statute miles are used for inland areas such as the Intracoastal Waterway and the Great Lakes. A nautical mile is 1/60th of a degree or minute of latitude. Roughly seven nautical miles equals eight statute miles.

Nearshore
The area from the high-tide line offshore to a depth of 20 fathoms (120 feet).

Neritic
Inhabiting coastal waters primarily over the continental shelf, generally over bottom depths equal to or less than 100 fathoms (183 meters) deep.

Nursery
The part of a fish or animal's habitat where the young grow up.

Observer
An individual hired to observe and record activities and catches (including bycatch) aboard fishing vessels or shoreside processing plants for purposes of managing the target and non-target species.

Oceanic
Inhabiting the open sea, ranging beyond the continental and insular shelves, beyond the neritic zone.

Open Access
A fishery in which no restrictions on entry or gear occur. License may be required in an open access fishery, but if no quotas in fishermen exist the fishery is still considered open access.

Operculum
The covering of the gills of a fish. Found in higher order fishes.

Optimum Yield (OY)
The harvest level for a species that achieves the greatest overall benefits, including economic, social, and biological considerations. Optimum yield is different than Maximum Sustainable Yield (MSY) in that MSY considers only the biology of the species. The term includes both commercial and recreational yields.

Otter Boards
Curved wood or steel doors, rectangular in shape, which are attached to the lines leading to the trawl net, used to spread the net open horizontally.

Otter Trawl
A cone-shaped net that is dragged along the sea bottom. Its mouth is kept open by floats on the headline, weights on the leadline, and two otter boards that shear outward as the net is towed.

Outrigger
A beam, spar, or framework projecting from or over the side of a ship or boat. Can be used to stabilize the vessel or spread out trolling lines.

Overcapacity
A level of fishing pressure that threatens to reduce a stock or complex below the abundance necessary to support maximum sustainable yield and allow an economically sustainable fishing industry.

Overfished
A fish population (stock) which size is sufficiently small to require a change in management practices to achieve an appropriate level and rate of rebuilding. Note that overfishing and overfished have different definitions.

Overfishing
Harvesting a fish population (stock) at a rate greater than which will meet the management goal within a particular year or season. Note that overfishing and overfished have different definitions.

Overutilized
When more fishing effort is employed than is necessary to achieve long-term potential yield.

Oviparity
A reproduction approach in which the species produces eggs that hatch outside the female's body.

Ovoviviparity
A reproduction approach in which an animal incubates their eggs inside the mother until they hatch.

Pelagic
Refers to fish and animals that live in the open sea, away from the sea bottom.

Permit Stacking
The registration of more than one limited entry permit for a single vessel, where a vessel is allowed additional catch for each additional permit registered for use with the vessel.

Photic
The depth of the water in a lake or ocean that is exposed to sufficient sunlight for photosynthesis to occur. The depth of the photic zone can be affected greatly by seasonal turbidity.

Phytoplankton
Microscopic planktonic plants.

Pinger
A device used underwater to produce pulses of sound, as for an echosounder.

Plug
A nonspecific term for any artificial lure having a distinct "body" made of wood or plastic and having one or more sets of single, double, or triple hooks attached. Most plugs are designed to wobble or create a commotion in the water when retrieved.

Polar
The areas of the globe surrounding the poles also known as frigid zones.

Population
Fish of the same species inhabiting a specified geographic area.

Predator
A species that feeds on other species (prey).

Primary Consumer
An animal that feeds on plants. Also known as an herbivore.

Primary Processor
A fish processor that are involved in the cleaning, filleting, and quick freezing of fresh seafood.

Primary Producer
Organisms in an ecosystem that produce biomass from inorganic compounds (autotrophs).

Processor
The entities that conduct the processing associated with fish and fish products between the time fish are caught or harvested, and the time the final product is delivered to the customer. Fish processors can be divided into two categories: primary and secondary.

Processing
The preparation or packaging of fish to render it suitable for human consumption, retail sale, industrial use, or long-term storage, including but not limited to cooking, canning, smoking, salting, drying, filleting, freezing, or rendering into meal or oil, but not heading and gutting unless additional preparation is done.

Quota
A portion of a total allowable catch that is allocated to a particular boat, fishery, region, or nation for a fishing season.

Quota Shares
A shore of the total allowable catch allocated to an operating unit such as a vessel, a company, or an individual fisherman (individual quota) depending on the system of allocation. Quotas may or may not be transferable, inheritable, and tradable. While generally used to allocate total allowable catch, quotas can also be used to allocate fishing effort or biomass.

Rebuilding
A state when you need to implement management measures that increase a fish stock to its target size.

Rebuilding Plan
The policy measures that will be used to rebuild the fish stock.

Rebuilding Analysis
The science that uses biological information to describe the probability that a stock will rebuild within a given timeframe under a particular management regime.

Recreational Angler
A fisherman that practices harvesting marine or freshwater resources for personal consumption and/or pleasure.

Recruit
An individual fish that has moved into a certain class, such as the spawning class or fishing-size class.

Recruitment
A measure of the number of fish that enter a class during some time period, such as the spawning class of fishing-size class.

Redd
The spawning ground or nest of certain fishes, including salmon.

Reduction Fishery
Harvested fish are processed into fishmeal, oils, or fertilizer.

Relative Abundance
An index used to compare the abundance of fish populations from year to year. This does not measure the actual numbers of fish, but shows changes in populations over time.

Restricted Access
Programs that limit the quantity of persons, vessels or fishing gear that may be engaged in the take of any given species of fish or shellfish. Restricted access may also limit the catch allocated to each fishery participant through harvest rights such as individual or community quotas.

Retail Market
Retail consists of the sale of physical goods or merchandise from a fixed location or by mail, in small or individual lots for direct consumption by the purchaser.

Rockfish Conservation Area (RCA)
Ocean waters 20-250 fathoms between Cape Mendocino, CA to Point Reyes, CA and 20-150 fathoms between Point Reyes, CA to the U.S./Mexico border. The purpose is to regulate all gear types that have a potentially significant affect on rebuilding of overfished rockfish species south of Cape Mendocino, CA.

Rockhopper
Gear that is attached to the "foot rope" of a trawl net. They vary in their design depending on the roughness of the seabed that is being fished: from small rubber discs for very smooth, sandy ground, to large metal balls, up to 0.5 m in diameter for very rough ground. They can also be designed to lift the net off the seabed when they hit an obstacle.

Rollers
Gear that is attached to the footrope in a trawl net that is made up steel or rubber that roll over the seafloor. The rollers allow the net to maneuver over structural seafloor obstacles and help to ensure that the footrope maintains constant contact with the seafloor.

Roller Trawl
A trawl net equipped with rollers than enable the net to go over rocky areas without snagging.

Roundfish
Any ordinary market fish, exclusive of Flounders, Sole, Halibut, and other flatfishes.

Roundhaul Net
A net, such as a purse seine, that encircles schools of fish.

Salmonids
A member of the Salmonidae family of fishes. Salmonids are the dominant fishes in the coldwater streams and lakes of North America, Europe, and Asia, where they support large recreational and commercial fisheries.

Saltonstall-Kennedy Act
Allocates 30% of the duties for imported fishery products to technological, biological, marketing, and other research and services in order to promote the free flow of domestically-produced fishery products and to develop markets for domestic fishery products.

Scales
Scales cover the skin of most bony and cartilaginous fishes. Scales vary enormously in size, shape, structure, and extent, ranging from rigid armor plates in fishes such as shrimpfishes and boxfishes, to microscopic or absent in fishes such as eels and anglerfishes. The morphology of a scale can be used to identify the species of fish they came from.

Sea Surface Temperature (SST)
The water temperature close to the oceans surface.

Seasonal Closures
The closure of a fishing ground for a defined period of time, used as a tool by fishery managers, frequently to protect a stock during a spawning season.

Secondary Processor
A fish processor that takes the product from the primary processor and further processes the product by canning or further cutting the seafood products preparing it for retail markets.

Seine Nets
A long flat net like a fence that are used to encircle a school of fish, with the boat driving around the fish in a circle.

Selectivity
The ability of a type of gear to catch a certain size or kind of fish, compared with its ability to catch other sizes or kinds.

Semelparous
A reproduction strategy when fish reproduce only once in their lifetime. Often, they die shortly after reproduction.

Set Gillnet
A gillnet that is anchored on both nets.

Setline
Fishing gear made up of a long main line attached to which are a large number of short branch lines. At the end of each branch line is a baited hook. When catching groundfish, setlines are laid on the seafloor. When catching fish in the water column, the setlines are buoyed near the surface. Setlines can be 20+ miles long. They are also called longlines.

Shellfish
General term for crustaceans and mollusks.

Short Ton
2,000 pounds.

Skiff
Any of various small boats, especially a flat-bottomed rowboat.

Slot Limit
A limit on the size of fish that may be kept. Allows a fisherman to keep fish under a minimum size and over a maximum size, but not those in between the minimum and maximum; or size limits that allow a harvester to keep only fish that fall between a minimum and maximum size.

Smolt
A term for a specific life stage in salmonids. In anadromous populations parr (small active fish with series of bars on their sides) transform into silvery smolts and migrate to the sea. Once in the ocean (or large lakes), the smolts gradually become mature and return to their home streams for spawning.

Social Impact Assessment (SIA)
An evaluation of the likely outcomes and impacts of a specific policy or regulation on a designated target group or groups, as well as likely ripple effects to other groups.

Socio-Economic
Pertaining to the combination or interaction of social and economic factors and involved topics such as distribution issues, labor market structure, social and opportunity costs, community dynamics, and decision-making process.

Spawning Biomass
The biomass of mature female fish at the beginning of the year.

Species
A group of similar fish that can freely interbreed.

Spermatophores
An aggregation of sperm held together by gelatinous material, or a gelatinous packet of sperm that is inserted into and attached to the female as part of reproductive behavior.

Spinning Gear
A type of recreational fishing reel with an open spool on the front end.

Spoon
An artificial lure with a curved or dished out body that wobbles but does not revolve. A spoon attracts fish by its movements as well as color.

Stakeholder
A person or organization that has a stake in a particular entity or resource such as a business, natural resource, or community.

Stern
The back portion of the boat.

Stewardship
An ethic that embodies responsible planning and management of resources. The concept of stewardship has been applied in diverse realms, including with respect to environment, economics, health, property, information, and religion and is linked to the concept of sustainability.

Stock
A grouping of fish usually based on genetic relationship, geographic distribution, and movement patterns. Also a managed unit of fish.

Stock Assessment (SA)
The scientific assessment of the status and well being of a fish population (stock) using the best-available science.

Straddling Stocks
Stocks of fish that migrate between, or occur in both, the economic exclusion zone (EEZ) of one or more states and the high seas.

Subpopulation
An identifiable fraction or subdivision of a population.

Subsistence Fishery
A fisherman that practices harvesting marine or freshwater resources for personal food, shelter, etc.

Substrate
A solid surface on which an organism lives or to which it is attached (also called substratum); or, a chemical that forms the basis of a biochemical reaction or acts as a nutrient for microorganisms.

Subtropical
Relating to the regions bordering on the tropical zone.

Supply & Demand
The phenomena in which as demand for an item increases, supplies of the item diminish and the price for the item increases. Conversely, if the supplies of the item increases or the demand decrease then the price for the item decreases. The relationship between the supply and demand for an item determined the price of the item in a market economy.

Suspension Feeder
An organism that feeds by capturing particles suspended in the water column. Also called filter feeders.

Sustainability
A state that can be maintained at a certain level indefinitely. The potential longevity of ecological systems, such as planet's climatic system, systems of agriculture, industry, forestry, fisheries, and the ecological infrastructure on which they depend.

Sustainable Use
The use of a resource at a rate that will meet the needs of the present without impairing the ability of future generations to meet their needs.

Swim Bladders
An internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming.

Target Fishing
Fishing for the primary purpose of catching a particular species or species group (the target species).

Temperate
The region between the tropic of Cancer and the arctic circle or between the tropic of Capricorn and the Antarctic circle.

Territorial Sea
A zone extending seaward from the shore or internal waters of a nation for a distance of 12 miles (19.3 km) as defined by the United Nations Conference on the Law of the Sea (UNCLOS). The coastal state has full authority over this zone but must allow rights of innocent passage.

Threatened Species
A classification under the Endangered Species Act. A species is considered threatened if it is likely to become an endangered species in the foreseeable future through a significant portion of its range.

Tickler Chains
A chain ground line to the footrope of a trawl net. It is hung four to eight inches below the regular footrope extending (in the Italian style net) from spreader to spreader.

Total Allowable Catch (TAC)
The catch limit for a particular fishery, generally for a year or fishing season. TACs are usually expressed in weight or for larger species, in numbers of fish.

Trammel Net
An entangling net that hangs down in several curtains.

Trawl
A sturdy bag or net that can be dragged along the ocean bottom, to catch fish.

Troll
To trail artificial or natural baits behind a moving boat. The bait can be made to skip along the surface or trailed below at any depth to just above the bottom. A bait or lure trailed behind an angler walking along a pier, bridge, or breakwater is also called trolling.

Trophic Structure
The way in which organisms utilize food resources and hence where energy transfers occurs within an ecosystem.

Tropical
A region banding the equator and extending 23.5 degrees to the north and south.

Turtle Excluder Device (TEDs)
An implement that has been certified to reduce the likelihood of capturing sea turtles.

Underutilized
When more fishing effort is required to achieve the long-term potential yield.

Upwelling
A rising of nutrient-rich water toward the sea surface.

Vessel Monitoring System (VMS)
A satellite communications system used to monitor fishing activities - for example, to ensure that vessels stay out of prohibited areas. The system is based on electronic devices (transceivers), which are installed on board vessels. These devices automatically send data to shore-based "satellite" monitoring systems.

Viviparity
A reproduction approach in which the female brings-forth living young, rather than laying eggs.

Water Column
The water from the surface to the bottom at a given point.

Wetfish
Also known as coastal pelagic species. Wetfish are primarily caught by commercial fishermen using roundhaul gear (purse seine, drum seine, lampara) for human consumption, bait, animal feed, and fish oil. Wetfish species include Market Squid, Northern Anchovies, Pacific Sardines, etc. They can be found anywhere from the surface to 1,000 meters deep.

Wholesaler
A business that sells, transports, and delivers goods to a retailer or other entity that then sells to the end customer. Price conscious consumers often try to avoid further mark-ups in price by purchasing directly from a wholesaler. Also called a distributor.

Year-Class
The fish spawned and hatched in a given year, a "generation" of fish.

Yield
In fisheries, yield is the percent of the original product available for sale after processing. The yield generally refers to the edible or marketable part of the seafood catch after cleaning, removing unwanted parts, etc.

Zooplankton
Animal members of plankton.