MLMA Master Plan Glossary

Adaptive Management

In regard to a marine fishery, a scientific policy that seeks to improve management of biological resources by viewing program actions as tools for learning, particularly in areas of scientific uncertainty. Actions shall be designed so that even if they fail, they will provide useful information for future actions. Monitoring and evaluation shall be emphasized so that the interaction of different elements within the system can be better understood.

Administrative Procedure Act (APA)

Statute that governs the regulatory process for federal agencies such as NOAA and other regulatory bodies. The state of California has its own APA in addition to the federal APA, which governs regulatory bodies such as the Department and Commission. The California APA requires that all proposed agency regulations be published in the California Regulatory Notice Register and remain open for public review and comment for a specified period of time. If a hearing is held, notice must be provided 45 days in advance and public comment by mail or at the hearing must be allowed. If the proposed regulation is then changed, the agency must make the revised regulation public 15 days before final action.


In regard to fisheries, allocation means the direct and deliberate distribution of the opportunity to participate in a fishery, or to receive a share of a catch quota, among identifiable, discrete user groups or individuals.

Acceptable Biological Catch (ABC)

The maximum amount of fish stock that can be harvested without adversely affecting recruitment of other components of the stock. The ABC level is typically higher than the total allowable catch, leaving a buffer between the two.

Annual Catch Limit (ACL)

A harvest specification set equal to or below acceptable biological catch in consideration of conservation objectives, socioeconomic concerns, management uncertainty, ecological concerns, and other factors. The ACL is a harvest limit that includes all sources of fishing-related mortality including landings, discard mortality, research catches, and catches in exempted fishing permit activities. Sector-specific ACLs can be used, especially in cases where a sector has a formal, long-term allocation of the harvestable surplus of a stock or stock complex.

Bag Limit

A limit per day or per trip on the number or weight of fish, invertebrates, or plants that a recreational fisherman may legally retain.


On or relating to the region at the bottom of a sea or ocean.

Billfish Conservation Act (BCA)

A federal statute that prohibits any person from offering billfish or billfish products for sale, selling them, or having custody, control, or possession of them for purposes of offering them for sale. NMFS is the lead federal agency. The BCA can be found at 16 United States Code §1827.

Biological Diversity/Biodiversity

A component and measure of ecosystem health and function. It is the number and genetic richness of different species found within a natural community or ecosystem, and of different communities and ecosystems found within a region.


The total weight or numbers of a stock or population.


Fish or other marine life that are taken in a fishery, but which are not the target of the fishery. Bycatch includes discards.

California Current/California Current Ecosystem (CCE)

The waters of the eastern Pacific Ocean that move south along the western coast of North America, beginning off southern British Columbia, flowing southward past Washington, Oregon and California, and ending off southern Baja California. The California Current is part of the North Pacific Gyre and brings cool waters southward. Additionally, extensive upwelling of colder sub-surface waters occurs, supporting large populations of whales, seabirds, phytoplankton, zooplankton, forage fishes, and important fisheries.

California Environmental Quality Act (CEQA)

This Act (Public Resources Code §21000 et seq.) identifies the significant environmental effects of California's public agencies’ actions and avoids or mitigates those significant environmental effects where feasible.


The potential of a vessel or a fleet of vessels to capture fish if not restricted by management measures. It is expressed as the number of fishery participants; size, gross tonnage, or horsepower of vessels; or the maximum amount of catch retainable on the vessel.

Catch (noun)

In regard to fisheries, the total amount (numbers or weight) caught, and sometimes only the amount landed or kept. Catch that is not landed is called discards.

Catch Limit

A limit on the total fishing mortality, including both landed catch and discard mortality. See Annual Catch Limit.

Catch Per Unit Effort (CPUE)

The catch obtained by a vessel, gear or fisherman per unit of fishing effort (e.g., number or weight of fish caught per hour of trawling). CPUE is sometimes used as a relative abundance index as well.


A value that modifies a unit of fishing effort in the calculation of fishing mortality which usually will depend on the habits of the fish or invertebrate, its abundance, and the type and deployment of fishing gear.

Climate Readiness

Characteristic of a fishery that uses expanded data collection of climate indicators from diverse sources, proactively incorporates climate information into management actions, practices adaptive decision- making that is flexible and responsive, and encourages collaboration with partners.


Traditional co-management refers to shared decision-making with government devolving (i.e., transferring or delegating) some of its power to others. The term has been used in a broader sense to refer to a variety of arrangements, with different degrees of power sharing, for joint decision-making by the state and community or user groups, about a set of resources or areas. No single standardized definition is used for fisheries or other natural resource sectors.

Commercial Fishery

Fishing in which harvested fish, invertebrates, or plants, either in whole or in part, are intended to enter commerce through sale, barter or trade.

Commercial Passenger Fishing Vessel (CPFV)

A licensed fishing vessel that takes recreational anglers fishing for a fee. Sometimes referred to as “charter vessels” or “party boats”.


In regard to fisheries, compliance means fishing in a manner that is in accordance with fishing regulations such as obtaining the required permits or licenses, with the allowed gears and within allowed areas and within seasons.

Collaborative Fisheries Research (CFR)

A process that involves two or more stakeholders (e.g., scientists, commercial fishermen, recreational fishermen, NGOs) in at least some aspect of research on a marine species or fishery.


Classification for a state in which essential fishery information is limited to an extent where traditional stock assessment methods may not be feasible, or results have a relatively high degree of uncertainty.


Classification for a state in which there is a relatively high level of essential fishery information.


In regard to fisheries, depletion means harvesting to unsustainably low levels, to the point that the population’s ability to grow and replenish is significantly reduced.


In regard to fisheries, depressed is the condition of a fishery for which the best available scientific information, and other relevant information that the Commission or Department possesses or receives, indicates a declining population trend has occurred over a period of time appropriate to that fishery. With regards to fisheries for which management is based on maximum sustainable yield, or in which a natural mortality rate is available, depressed means the condition of a fishery that exhibits declining levels of fish abundance below those consistent with maximum sustainable yield.


Fish that are taken in a fishery but are not retained because they are of an undesirable species, size, sex, or quality (i.e., bycatch), or because they are required by law not to be retained.


The physical and climatic features and all the living and dead organisms in an area that are interrelated in the transfer of energy and material, which together produce and maintain a characteristic type of biological community. Marine ecosystems can be particularly complex due to the vastness of the marine environment, the large number of organisms, and the intricacies of the physical, chemical, biological, and social processes involved.

Ecosystem-based Fishery Management (EBFM)

An environmental management approach relying on credible science that recognizes the full array of interactions within an ecosystem, including humans, rather than considering single issues, species, or ecosystem services in isolation.

Ecosystem Indicator

An indicator that can serve as a proxy for overall condition of the ecosystem. It could be the abundance of a keystone species, biodiversity measurement, or biomass, etc. Selection of appropriate indicators is key to properly communicating between stakeholders and managers.

Ecological Risk Assessment (ERA)

The assessment of environmental effects of certain stressors and their immediate and long-term potential damage or harm to an ecosystem. Risk assessment is aimed at better identifying which species might be most adversely affected by a stressor by assessing the probability, or risk, of effects. Within the context of marine systems, risk assessment has been applied to compare the importance of individual stressors and to identify which species face the greatest threat from individual or multiple stressors.


The amount of time and fishing power used to harvest fish, invertebrates, or plants, whether by individuals or vessels. For vessels, fishing power includes gear size, boat size, and horsepower. Used to calculate catch per unit effort.

Effort Control

Management action intended to reduce fishing activities to conserve resources. These may include limited entry programs, individual transferable quotas, catch limits per license, and gear restrictions.

Electronic Monitoring (EM)

In regard to fisheries, EM means technologies such as digital cameras, sensors, tablets, and online entries to track fishing vessels’ catch, bycatch, and discards at sea. These are increasingly being used in place of human observers onboard vessels that lack space or funding.

Emerging Fishery

The MLMA definition in regard to a marine fishery, means both of the following:

  1. A fishery that the director has determined is an emerging fishery, based on criteria that are approved by the commission and are related to a trend of increased landings or participants in the fishery and the degree of existing regulation of the fishery.
  2. A fishery that is not an established fishery. "Established fishery," in regard to a marine fishery, means, prior to January 1, 1999, one or more of the following:
  1. A restricted access fishery has been established in this code or in regulations adopted by the commission.
  2. A fishery, for which a federal fishery management plan exists, and in which the catch is limited within a designated time
  3. A fishery for which a population estimate and catch quota is established
  4. A fishery for which regulations for the fishery are considered at least biennially by the commission.
  5. A fishery for which this code or regulations adopted by the commission prescribes at least two management measures developed for the purpose of sustaining the fishery. Management measures include minimum or maximum size limits, seasons, time, gear, area restriction, and prohibition on sale or possession of

Endangered Species Act (ESA)

A federal statute that provides for the conservation of threatened and endangered plants and animals and the habitats in which they are found. The lead federal agencies for implementing ESA are the U.S. Fish and Wildlife Service and NMFS. The law requires federal agencies, in consultation with the U.S. Fish and Wildlife Service and/or NMFS, to ensure that actions they authorize, fund, or carry out are not likely to jeopardize the continued existence of any listed species or result in the destruction or adverse modification of designated critical habitat of such species. The law also prohibits any action that causes a "taking" of any listed species of endangered fish or wildlife. Likewise, import, export, interstate, and foreign commerce of listed species are all generally prohibited. The ESA is found at 16 United States Code §1531 et seq.

Enhanced Status Report (ESR)

A revised approach to Status of the Fisheries Reports. ESRs are proposed to have sections on the history and socioeconomics of the fishery, the biology and status of target stocks, ecosystem aspects of the fishery, past and current conservation and management measures, essential fisheries information, monitoring and future research and management needs. This revised format would help ensure a basic standard of MLMA-based management is applied across all fisheries in a consistent and transparent fashion. It would summarize all the available essential fisheries information for each fishery and make it readily apparent what is not available. This structure is envisioned to assist the Department in planning both short and long-term research activities and inform external parties about research opportunities that may benefit management through a dynamic web-based platform.


In regard to fisheries, entanglement occurs when a marine species become trapped or tangled in fishing gear. It is not used to describe fish that are caught in nets but rather species including sea turtles, marine mammals, and seabirds that are unintentionally entangled.

Essential Fishery Information (EFI)

In regard to fisheries, EFI refers to information about fish, invertebrate, or plant life history and habitat requirements; the status and trends of populations, fishing effort, and catch levels; fishery effects on age structure and on other marine living resources and users, and any other information related to the biology of a species or to its take in a fishery that is necessary to permit fisheries to be managed according to the requirements of this code.

Experimental Gear Permit

Permit issued under special review of the Commission that allows the use of gear that is not permitted under any other permits or licenses in order to allow new gears to be developed and improved.

External Peer Review Panel

In the context of MLMA, this term means a group of experts who review the scientific basis of a fishery management document and evaluate the scientific soundness of the document. The panel members cannot be employees or officers of the Department or the Commission and cannot have helped with the development of the document.


Any species of bony fish (teleosts) or cartilaginous fish (sharks, skates and rays). Finfish do not include reptiles, amphibians, invertebrates, plants or algae.


Means either of the following:

  1. One or more populations of marine fish, invertebrates, or plants that may be treated as a unit for purposes of conservation and management and that are identified on the basis of geographical, scientific, technical, recreational, and economic characteristics; or
  2. Fishing for or harvesting of the populations described in (a).

Fishery-dependent Data

Information collected directly from a fishery, such as sampling catch at landing sites and information from commercial landing receipts and commercial and commercial fishing passenger vessel logbooks.

Fishery-independent Data

Information collected separately or independent of fishery landing or catch data.

Fishery Management Plan (FMP)

A planning document based on the best available scientific knowledge and other relevant information that contains a comprehensive review of the fishery along with clear objectives and measures to ensure its sustainability. Components of an FMP are described in the MLMA.

Fishing Season

A management tool that only permits fishing within set dates. This tool can be used to reduce effort or to protect target stocks during reproductive or other sensitive periods. Different fisheries and species have different seasons as decided by managers; the season is the period of time within which the fish may be caught and retained.

Forage Fish

May refer to vertebrate and invertebrate species that provide food for marine fish, mammals, and birds. Forage fish may be targeted for direct human consumption, such as anchovies or sardines, but are most often targeted for fishmeal production or as bait for other species.

Gear Restrictions

A management tool that is intended to limit fishing effort or impacts from fishing by limiting the use of, or banning, certain gears or types of gear. This may be done by only specifying allowed gears and banning the use of all others, specifying banned gears and allowing the use of all others, and/or banning or requiring gear components or specifications (e.g., mesh size).

Gill Net

A passive capture gear constructed of vertical panels of netting, hung between a ground line and a float line, and set in a straight line, in which fish can become entangled. Gill nets are classified as either set or drift.


Finfish species that live and feed on or near the bottom of the seafloor. Groundfish are often managed as a single multispecies fishery. Common targeted groundfish species include rockfishes, flatfishes, skates, cod, and whiting.


The physical, chemical, and biological features of the environment where an organism lives.

Harvest Control Rule (HCR)

A primary mechanism for achieving sustainable use, preventing overfishing, preserving habitat, rebuilding depressed stocks, and recognizing the importance of non-consumptive uses. HCRs must be based on objective, measurable criteria such as population size, productivity, or density, or other inputs. An HCR specifies the approach to setting acceptable biological catch, maximum sustainable yield, or another catch parameter for a stock or stock complex as a function of the scientific uncertainty in the estimate of overfishing limit and any other scientific uncertainty. The HCR may include explicit, stock- or complex-specific definitions of overfished or other categories. Once established, an HCR becomes the default harvest policy for managers. In general, HCRs help identify key management measures appropriate to the fishery.


Any type of fishing gear involving a fishing line with attached hooks (e.g., longline, rod-and-reel, troll, and stick gear).

Incidental Catch

Fish caught incidentally during the pursuit of the primary target species, but legal and desirable to be sold or kept for consumption.


A measure of a component or process that can serve as a proxy for values that are difficult to calculate, such as abundance of a species or ecosystem health. For example, catch per unit effort is often used as an indicator of stock abundance or availability.

Individual Transferable Quota (ITQ)

A limited access system to harvest a quantity of fish, expressed by a unit or units representing a percentage of the total allowable catch of a fishery that may be received or held for exclusive use by a person.

Input Controls

Regulations created by fishery managers to limit or control fishing impacts by limiting fishing effort, such as fishing seasons and area closures, gear restrictions, and limited access programs.

Landing Receipt

A document provided by the Department to commercial fish markets, fish dealers, fish processors, and fishermen for recording landing information. Information required includes date, port of landing, species or market category of fish, pounds landed, and price paid.


The number or weight of fish unloaded at a dock by commercial fishermen or brought to shore by recreational fishermen for personal use. A landing is reported at the point at which fish are brought to shore. Note that landings, catch, and harvest are all distinct metrics.

Life History

The history of changes an organism passes through in its development from egg, spore, or other primary stage until its natural death.

Limited Access/Entry

See restricted access.


Records of fishing activity and catch maintained by commercial fishermen as required for some fisheries.

Magnuson-Stevens Fishery Conservation and Management Act (MSA)

A federal statute that governs marine fisheries in the United States. The Act defines the role of regional fishery management councils and describes their functions and operating procedures. It also includes national standards for management and outlines the contents of fishery management plans. NMFS is the lead federal agency charged with implementation of the Act. The MSA can be found at 16 United States Code §1801 et seq.

Management Strategy Evaluation (MSE)

A formal process to evaluate the performance of alternative management procedures for a fishery, prior to any implementation. MSEs vary between fisheries, but typically utilize models to assess the current status of the fishery, as well as assumptions or additional models to determine the effects of potential management actions.

Marine Life Management Act (MLMA)

Passed in 1998 by the California Legislature under Assembly Bill 1241, the MLMA significantly changed the way California’s marine fisheries are managed and regulated. It expanded the responsibilities of the Department and Commission, and increased stakeholder involvement in the development of fishery management plans.

Marine Life Protection Act (MLPA)

The MLPA was passed in 1999 by the California Legislature, directing the Department to redesign California’s existing system of marine protected areas to increase its coherence and effectiveness for protecting the state’s marine life, habitats, and ecosystems.

Marine Living Resources

Includes all wild mammals, birds, reptiles, fish, and plants that normally occur in or are associated with ocean and estuarine waters, and the marine habitats upon which these animals and plants depend for their continued viability.

Marine Mammal Protection Act (MMPA)

Passed in 1978, this Act protects all marine mammals in US waters and prohibits their take except that which is permitted specifically for tribal subsistence, scientific research, and limited incidental catch that is inherent in other fishing activities.

Marine Protected Area (MPA)

A named, discrete geographic marine or estuarine area seaward of the mean high tide line or the mouth of a coastal river, including any area of intertidal or subtidal terrain, together with its overlying water and associated flora and fauna that has been designated by law or administrative action to protect or conserve marine life and habitat. MPAs are primarily intended to protect or conserve marine life and habitat, and are therefore a subset of marine managed areas, which are broader groups of named, discrete geographic areas along the coast that protect, conserve, or otherwise manage a variety of resources and uses, including living marine resources, cultural and historical resources, and recreational opportunities.

Maximum Economic Yield (MEY)

The maximum possible revenue after accounting for the costs of fishing that may be achieved in a fishery. MEY typically is reached at smaller catches than maximum sustainable yield.

Maximum Sustainable Yield (MSY)

The highest average yield over time that does not result in a continuing reduction in stock abundance, taking into account fluctuations in abundance and environmental variability.

Migratory Bird Treaty Act (MBTA)

Implemented in 1916 between Great Britain and the United States, the MBTA prohibited the harvest of birds that migrate between Canada and the United States, as well as the take of their feathers, eggs or nests. Similar agreements have expanded these protections to birds that migrate to/from the United States, Japan, Mexico, and Russia.


An equation that can be used to predict management outcomes based on hypothetical and/or measured values. Management tools such as maximum sustainable yield, optimum yield, and stock assessments utilize models.


In regard to fisheries, monitoring refers to management activities that keep records of fishing and biological data, such as landings records or sampling of the catch. Monitoring may also refer to the monitoring of compliance with environmental regulations during fishing activities.

Mortality (Total or Fishing)

Total mortality is the sum total of individual deaths within a population. Usually, it is stated as an annual rate and calculated as the sum of fishing mortality (deaths due to fishing), deaths due to natural causes (e.g., predation, disease), and deaths due to non-fishing, artificial causes (e.g., pollution, seismic surveys).

Non-consumptive Activities

Activities that do not include removal of resources such as photography, whale watching or diving.


All oceanic waters outside state waters or deeper than 100 fathoms, in comparison to nearshore.

Optimum Yield (OY)

In regard to a marine fishery, OY means the amount of fish taken in a fishery that does all of the following:

  1. Provides the greatest overall benefit to the people of California, particularly with respect to food production and recreational opportunities, and takes into account the protection of marine ecosystems;
  2. Is the maximum sustainable yield of the fishery, as reduced by relevant economic, social, or ecological factors; and
  3. In the case of an overfished fishery, provides for rebuilding to a level consistent with producing maximum sustainable yield in the

Output Controls

Management tools used to limit or control fishing impacts by limiting catch, such as total allowable catch, trip limits, and bycatch limits.


A fishery is labeled overfished based on quantitative thresholds established by the agency with authority over that fishery. The MLMA definition of “overfished” with regard to a marine fishery, means both of the following:

  1. A depressed fishery; and
  2. A reduction of take in the fishery is the principal means for rebuilding the


A rate or level of take that the best available scientific information, and other relevant information that the Commission or Department possesses or receives, indicates is not sustainable or that jeopardizes the capacity of a marine fishery to produce the maximum sustainable yield on a continuing basis.

Overfishing Limit (OFL)

The maximum sustainable yield harvest level or the annual abundance of exploitable biomass of a stock or stock complex multiplied by the maximum fishing mortality threshold or proxy thereof. OFL is an estimate of the catch level above which overfishing is occurring.


In regard to a fishery, participants refer to the sport fishing, commercial fishing, and fish receiving and processing sectors of the fishery.


Pertaining to the water column, or referring to organisms living in the water column, as opposed to those living on the seafloor.

Permit Fees

Money paid to the respective regulatory body to obtain a permit. Fees typically go to conservation funds or are used to offset management costs.

Precautionary Management

A resource management framework that implements conservation measures even in the absence of scientific certainty that fish stocks are being overexploited.


In regard to fisheries, a processor is a business, individual or vessel that is involved in the preparation or packaging of fish/marine resources to render them suitable for human consumption, pet food, industrial uses or long-term storage. This includes but is not limited to: cooking, canning, smoking, salting, drying, filleting, freezing, or rendering into meal or oil, but does not mean heading and gutting unless there is additional preparation.


The birth, growth, and death rates of a stock. A highly productive stock is characterized by high birth, growth and mortality rates, and therefore, high turnover. Such stocks can usually sustain higher exploitation rates and, if depleted, could recover more rapidly than comparatively less productive stocks.

Productivity and Susceptibility Analysis (PSA)

A model that scores the productivity (ability to recover following depletion) and susceptibility (potential impacts from fishing) of a species, collectively known as vulnerability.


A limit on the amount of fish which may be landed in any one fishing season or year. May apply to the total fishery, a geographical area, or an individual share.


The implementation of management measures that increase a fish stock to its target size. Rebuilding measures are commonly implemented for overfished species.

Recreational/Sport Fishery

Fishing with no intentions of, or ability to, sell catch.


A measure of the number of fish that survive to a particular life stage, often used to predict future population size. Some examples include the number of offspring that survive the larval stage and reach the juvenile stage (larval recruitment), the number of individuals that survive (i.e., recruit) to the next year (e.g., age two recruits), the number of fish that reach sexual maturity (i.e., recruit to the spawning population), or in the case of a fishery, the number of fish that recruit to the catchable component of the population.

Reference Point

Reference points are quantitative (numerical) values that inform managers about the current status of a stock. Two important types must be considered, target and threshold (or limit) reference points. Target reference point is a numerical value that indicates that the status of a stock is at a desirable level; often management is geared towards achieving or maintaining this target. Threshold (limit) reference point is a numerical value that indicates that the status of a stock is unacceptable (e.g., overfished or too small) and management action should be taken to improve stock status.

Regulatory Discard

Fish harvested unintentionally in a fishery that fishermen are required by regulation to discard whenever caught, or are required by regulation to retain but not sell.

Restricted Access

Restriction of the right to participate in a fishery, using permits or other means. This is one method managers may use to ensure sustainable fisheries, reduce fishing effort, or protect recovering or threatened stocks.


The process of developing regulations which occurs in several steps, including publishing proposed rules, accepting comments on the proposed rule, and publishing the final rule. Rulemaking is used to create specific actions and regulations that are designed to carry out the intent of environmental legislation and policy.


Different, although sometimes overlapping, groups of fishermen that are subject to their own regulations. For example, the federal groundfish fishery off the West Coast is managed by the following sectors: limited-entry trawl, limited-entry fixed gear, tribal, recreational, and open-access.


A type of net that is deployed by encircling fish. Purse seines are used to catch fish within the water column or near the surface, while demersal seines are used to target fish on the seafloor.

Set net

A type of gill net that is set in place with buoys and/or anchors and catches fish that swim into it and become entangled.

Size Limit

A regulation requiring that landed fish fall below or above a certain size threshold. Minimum size limits are typically intended to prevent the harvest of juvenile or young individuals before they have reproduced. Maximum size limits are typically intended to prevent the harvest of highly fecund female fish. Size limits may be sex-specific for some species.

Spawning Potential Ratio (SPR)

A ratio of the number of eggs produced during the lifetime of an average female in a fished population to the number of eggs produced during the lifetime of an average female in an unfished population. SPR is used to characterize the amount of impact fishing has on a population’s ability to reproduce.


One who has an impact on, is impacted by, or is interested in something, such as a fishery or marine protected area.

Stakeholder Engagement/Involvement (in the Master Plan)

Also referred to as public involvement in the Master Plan, and may mean establishing communication between managers and stakeholders through outreach, workshops or meetings. It may also involve receiving feedback and input from stakeholders in the creation of management goals.


In regard to fisheries: a species, subspecies, geographical grouping, or other category of fish, invertebrate, or plant that can be managed as a unit.

Stock Assessment

A management tool that uses modeling and historic and current population data or trends to determine the status (e.g., productivity, biomass, population size) of a fishery, in order to determine at what level it may be sustainably exploited.


The potential for a stock to be impacted by a fishery, which includes direct captures, as well as indirect impacts of the fishery (e.g., loss of habitat quality).


The surface or medium on or in which an organism lives (e.g., mud, sand, rocks).


"Sustainable," "sustainable use," and "sustainability," with regard to a marine fishery, mean both of the following:

  1. Continuous replacement of resources, taking into account fluctuations in abundance and environmental variability; and
  2. Securing the fullest possible range of present and long-term economic, social, and ecological benefits, maintaining biological diversity, and, in the case of fishery management based on maximum sustainable yield, providing for a fishery that does not exceed optimum

Total Allowable Catch (TAC)

A specified numerical catch (including discard mortality) for each fishing season, the attainment (or expected attainment) of which may cause closure of the fishery.

Total Allowable Effort (TAE)

A specified numerical effort objective for each fishing season. This can be expressed in number of boats, amount of gear used, etc., and is controlled and adjusted through permits and licenses.

Trap Limit

A regulatory measure that restricts the number of traps a fisherman may have in the water at the same time.


A large net that is tapered and forms a flattened cone. The mouth of the net is kept open while it is towed or dragged, either in the pelagic habitat (midwater trawl) or over the sea bottom (otter trawl or bottom trawl).

Tribal Consultation

In regard to fisheries, Tribal consultation means the process of engaging in government-to-government dialogue with Tribes and Tribes on the contact list maintained by the Native American Heritage Commission in a timely manner and in good faith. Tribal consultation provides Tribes and tribal communities with necessary information and to seek out, discuss, and give full and meaningful consideration to the views of Tribes and tribal communities in an effort to reach a mutually agreed upon resolution of any concerns expressed by the Tribes and tribal communities or the managers.

Unfished Biomass (B0)

The hypothetical predicted biomass of fish or invertebrates within a stock if no fishing were occurring.


In regard to fisheries, vulnerability refers to a stock’s susceptibility to suffer mortality from fishing or to experience overfishing.


The total number or biomass of fish, invertebrates, or plants harvested.

Yield Per Recruit (YPR)

A theoretical value that describes the yield to a fishery that is contributed by a given number of recruits (usually a single recruit).