Fisheries laws and management plans may be public, but they are often buried in dense, technical language that makes it difficult for the public to understand and hold decision-makers accountable. This glossary of 28 key fisheries terms is designed to change that. By giving you the tools to understand how fisheries are managed—and mismanaged—we aim to empower more people to speak up, get involved, and defend truly sustainable fisheries in British Columbia (B.C.).
Definitions – in alphabetical order:
Abundance
Abundance is the number of fish in a stock (see definition 33) or a population.
Age Composition
Age composition refers to the proportion of fish of different ages within a stock (see definition 33) or the catch. Understanding age composition matters because most fish can only reproduce once they reach a certain age. For example, herring typically become sexually mature at 3-5 years old, while some rockfish species take over 20 years. Healthy populations depend on having enough mature individuals to reproduce and sustain themselves.
Example:
In 2024, B.C.’s Pacific herring age composition was: 7.9% age 2, 37.5% age 3, 32.7% age 4, 11.4% age 5, 7.1% age 6, 2.7% age 7, 0.5% age 8, and 0.2% age 9. Figure 1 shows changes in B.C. Pacific herring age structure from 2014 to 2024.
For Pacific herring, the loss of mature individuals is especially damaging because older fish play a crucial cultural role within the school. Research shows that elder herring act as knowledge holders, guiding younger fish to traditional spawning grounds. When too many mature fish are removed, this knowledge is lost, disrupting migration patterns and weakening the population’s ability to successfully reproduce.
At-Sea Observer
DFO’s At-Sea Observer Program provides independent, third-party monitoring of commercial fishing activity. Trained observers, designated by DFO and employed by certified service providers, are placed aboard fishing vessels to document what is caught and how. They record the amount and species of fish harvested, where fishing occurs, and the gear or methods used. Observer coverage refers to the requirement that a vessel carry one or more observers for a set portion of its fishing time.
This program aims to provide transparency and accountability in commercial fisheries, but its structure raises serious concerns about data reliability. Numerous reports and investigations have documented allegations of harassment, threats, and even sexual violence against observers, particularly women, working alone on vessels without adequate communication tools or safety support. Whistleblowers have reported abuse and pressure from fishers to alter data, yet received little protection or follow-up from DFO and their employers, leaving them vulnerable and isolated.
Under these conditions, observers face pressure to downplay or falsify their findings, contributing to chronic under-reporting of bycatch and discards. Observer companies, hired and paid by the industry they monitor, create a structural conflict of interest that may exacerbate interference. As a result, the program often fails to deliver the accurate, independent data it is mandated to provide. These issues intensified during the COVID-19 pandemic, when DFO removed observers from groundfish trawl vessels and relied solely on electronic monitoring for enforcement, creating a significant gap in on-the-water oversight.
Biomass
Biomass is the total weight of all the fish in a stock or a population.
Bottom Trawling
Bottom trawling is a non-selective fishing technique where vessels drag large, weighted nets along the seafloor. These nets capture everything in their path, carving deep furrows through sensitive ecosystems and destroying already endangered coral and sponge reefs. They also stir up sediment, releasing stored carbon into the marine environment. In their wake, bottom trawl nets leave gaping ecological scars that may take decades to heal and it has been likened to marine deforestation.
Bycatch
Bycatch refers to animals unintentionally captured while fishing for a target species. This includes non-target fish species, sea turtles, invertebrates, seabirds, and marine mammals, as well as unwanted individuals of the target species, such as juveniles or undersized fish. Bycatch may be alive, injured, or dead when caught.
It can be discarded at sea as “released catch”, either directly from the gear or after being brought on board. Alternatively, landed bycatch may be retained and counted toward the vessel’s total catch, or be used for lower-value purposes like pet food, fertilizer, or bait, or discarded as offal (waste) at the dock.
Closed containment farm
A closed containment farm is an aquaculture system that raises fish within physical barriers, like floating bags or land-based recirculating tanks, to limit or eliminate water exchange with the surrounding environment. These barriers minimize interactions between farmed fish and the ocean, helping prevent the spread of disease, parasites, and pollution to wild ecosystems.
Containment systems exist along a spectrum. Traditional open-net pens allow free flow of water, waste, and parasites between farmed and wild fish. “Next-generation” or semi-closed systems provide partial barriers but still allow significant water exchange, offering limited protection. High-level closed containment systems use solid walls or membranes, draw cleaner water from deeper layers, collect dead fish, and capture or treat waste before it can enter the ocean. While some of these designs represent meaningful progress, others, especially those that still release large volumes of untreated water or uncollected waste, do not offer sufficient safeguards for wild fish or the ecosystems they rely on.
Dockside monitoring
Dockside monitoring is a third-party program, run by designated companies like Archipelago Research, that verifies species composition and landed weight of fish when commercial vessels offload their catch at the dock. Many fishing licences require participation in this program.
Electronic monitoring
Electronic monitoring uses cameras, sensors, and computers installed on fishing vessels to digitally record fishing activity. It supplements or replaces at-sea observers by documenting gear deployment, catch, and bycatch.
During Covid-19, at-sea observers in the groundfish trawl fishery were replaced by camera-based electronic monitoring. Both observer coverage and electronic monitoring services are outsourced to private third-party companies, such as Archipelago. In practice, only about 10% of the video footage is reviewed, and for the groundfish trawl fishery, it is typically deleted after about one month unless discrepancies are detected. Even though it documents the harvesting of a public resource, this video is treated as proprietary and is not accessible to the public for independent review.
There are also basic reliability problems. For example, 2022/2023 enforcement reports (covering the start of the 2022/23 fishing season to November 7, 2022) for the groundfish trawl fishery show that at least one vessel completed an entire trip without a working camera; cameras were too dirty to see activity in at least two incidents; and two vessels fished the west coast with only two cameras in operation when three are required. These gaps show that without strong standards and oversight, electronic monitoring can fail to deliver the robust, transparent data that sustainable fisheries demand.
Escapement
Escapement is the number of fish that “escape” the fishery and reach their spawning grounds. The term applies mainly to salmon and similar fisheries. For a salmon run, total run size is typically conceptualized as catch plus escapement (assuming no other mortality). Managers set escapement goals to try to ensure sufficient spawning each year.
Forage Fish
Forage fish are small, schooling species that occupy lower food-chain positions and serve as key prey for larger predators. They face high predation mortality and often show large natural swings in abundance over short timescales.
On the B.C. coast, Pacific herring are a critical forage fish, helping transfer energy from phytoplankton and zooplankton to larger marine animals such as fish, seabirds, and marine mammals. Rich in lipids and protein, they are one of the most energy-rich prey species in the marine food web and an important food source for a wide range of predators, from salmon and seabirds to whales.
Food and Bait Fishery
The Food and Bait Fishery typically catches herring from November to January, before the roe herring season. Most herring caught in the Strait of Georgia Food and Bait fishery are shipped to Australia for feeding ocean ranched tuna, or used as feed for captive animals in aquariums. Although DFO states that the Food and Bait fishery targets migratory stocks, evidence shows many regions hold both local and migratory populations – harvested as one. The key distinction between these populations has been under-researched and unmentioned in management plans, despite recognition of local, non-migratory herring populations since 1934.
In 2025/26 alone, DFO allocated 2,100 tons to the Food and Bait fishery, despite documented declines of local stocks and concerns from First Nations, scientists, and coastal communities. While about 5% of the catch goes to charity, most ends up as bait or low-value products, with little reaching Canadian plates.
Food Social Ceremonial Fishery
The Food, Social and Ceremonial (FSC) Fishery provides designated Indigenous harvesters the opportunity to fish for themselves and/or their community for food, social, or ceremonial purposes, not for commercial sale. The right is protected under section 35 of the Constitution. A FSC fishing license is a communal license issued to an Indigenous Nation under the Aboriginal Communal Fishing Licences Regulations, authorizing the Nation to designate members to fish under it. DFO develops these licences in consultation with Indigenous groups, with conditions tailored to each community. This fishery counts toward the total herring quota; for example, in 2025/2026, only 0,002% of the Strait of Georgia herring quota was allocated to FSC.
Foundational / Foundation Species
A foundational species is one that, under natural conditions, is extremely abundant and makes up a large share of an ecosystem’s biomass. Foundational species sit near the base of ecological interaction networks. They form many non-trophic or mutualistic links with other species, such as providing habitat structure, altering environmental conditions, or influencing energy and nutrient flows. Because so many other species depend on them, changes in a foundational species can transform entire ecosystems.
An example of a foundational species is salmon. Salmon define ecosystems, control the abundance and diversity of hundreds of species, and modulate critical ecosystem processes throughout their life cycle. Dependent species include wolves, bears, seabirds, and Southern Resident killer whales.
Gill Net Fishery
A gill net fishery uses gill nets to catch fish. A gill net is a rectangular curtain of netting that hangs vertically in the water, held up by floats on top and weights or stakes at the bottom. Unlike a seine net, a gill net does not enclose an area of water; it intercepts fish as they swim. Gill net fisheries use either drifting gillnets (which drift near the surface or bottom and are often attached to the vessel), or fixed gillnets (which are secured to stakes in coastal waters).
Hail report
A hail report is a mandatory notification from a commercial fishing vessel to the DFO (often via a third-party company) that provides information such as vessel identity, location, fishing activity, and catches. Hails are typically required before leaving port, during fishing, and before returning to port (hailing in/out).
Herring Kill Fishery
The Herring Kill Fishery refers to commercial fisheries that lethally harvest herring, either targeting the whole fish or roe alone. Though not an official DFO term, Pacific Wild uses it to describe the B.C. fisheries listed below:
- Food and Bait Fishery (see definition 12)
- Special Use Fishery (see definition 32)
- Roe Fishery (see definition 28)
Pacific Wild uses the term “herring kill fishery,” to distinguish certain types of fisheries that harvest herring more and less sustainably. The commercial spawn-on-kelp fishery for example, is a non-lethal and sustainable alternative to the Roe Kill Fishery.
IFMP
An IFMP is an acronym for Integrated Fisheries Management Plan. IFMPs set out the objectives, rules, and supporting legislation, and policies for managing a fishery over a set period. For example, the 2025/2026 Pacific Herring IFMP detailed management measures for that fishery, covering from November 7, 2025 to November 6, 2026. These plans are created by DFO, an acronym for Fisheries and Oceans Canada, which is a department of Canada’s federal government.
Landed value
A landing is the quantity of catch transferred from a licensed vessel to land, such as docks or wharves. The landed value is the monetary value of that catch at the time of landing or first sale, before processing, transport, or retail sale. In simpler terms, landed value is what the fisher gets paid at the dock.
Figure 2. Provincial quantities and landed value of Pacific Herring (1991-2021). Data sourced from DFO Seafisheries Landings and Annual Commercial Statistics Reports.
The landed value of Pacific Herring has declined for decades – fisheries now earn less profit from sales. For instance, the average landed value dropped from $1.78/kg in 1990 to ~$0.46/kg in 2022 (unadjusted for inflation).
Logbook
A logbook is an official record where fish harvesters document catch and effort information and submit it to DFO. Formats include traditional paper logbooks and electronic logbooks (ELOG). Harvesters must maintain a logbook under the Fisheries Act, with fishing licenses specifying required details.
Maximum sustainable yield (MSY)
The maximum sustainable yield (MSY) is the largest average catch that can be taken from a stock under current environmental conditions without damaging its ability to reproduce. In theory, this catch sustains the stock year after year. In practice, however, MSY has serious limitations.
It assumes accurate estimates of stock size and productivity, plus stable environmental conditions, but data is often uncertain and ocean conditions are changing rapidly. Overestimating a stock or its productivity can make MSY-based quotas too high, driving populations down. MSY focuses on one species at a time and on “average” conditions, ignoring ecosystem interactions, climate change, and the risks of harvesting the “maximum” from every species at once.
These flaws are not theoretical: overly optimistic MSY-style assessments contributed to the collapse of Northern cod on Canada’s East Coast. Though Canada now uses more precautionary targets, MSY reference points still underpin many decisions, leaving risks if uncertainty and political pressures are not tightly managed.
Midwater trawling
Midwater trawling is a fishing method that involves dragging a large net through the mid-depths of the water column to capture schooling fish such as Pacific hake. Like bottom trawling, it is largely non-selective, resulting in significant bycatch, and affecting over 100 B.C. marine species, including endangered ones like basking sharks. In Alaska, this fishing method has entangled and killed large marine mammals, such as fin and humpback whales. In 2023, ten killer whales (from both Bigg’s (transient) and resident populations), were infamously caught in trawl nets in the Bering Sea and Aleutian Islands.
Natural mortality
Natural mortality refers to fish deaths from all causes except fishing, such as predation, disease, prey availability, climate conditions, and pollution. It is often summarized by the natural mortality rate, denoted as “M” – roughly the proportion of fish in a stock that die of natural causes each year.
Scientific literature over the past decade reports increased natural mortality (M) for Pacific salmon in both freshwater and marine life stages.
Open-net pen salmon farm
Open-net pen salmon farms consist of floating “cages” made of nets that hold farmed salmon, while allowing water to flow freely between the farm and the surrounding environment. This design enables waste, chemicals, parasites, diseases, and escaped farmed fish to spread, posing serious risks to wild populations. Open-net pens also attract predators, like sea lions and whales, which can become entangled in the nets or prey like Pacific herring which can enter the nets and be eaten by salmon or otherwise harmed by the fish farming equipment such as Hydrolicers.
In B.C., the federal government announced plans to phase out and fully ban open-net pen salmon aquaculture in coastal waters by June 30, 2029, transitioning to closed containment and other alternative systems for better wild Pacific salmon protection.
Quota
A quota is a fixed amount of catch that a licence holder, vessel, company, or country may harvest from a fish stock during a specified fishing season. This fishing season may vary, for example, the trawl fishery operates year-round, whereas the herring roe fishery typically lasts only a few days to weeks.
See the definition on Total Allowable Catch for more context.
Recruitment
Recruitment is the process by which young fish survive their egg, larval, and juvenile stages to become part of the fishable stock – typically when they grow large enough to be vulnerable to fishery gear. Thus, they are “recruited” into the exploitable population. It can also refer to the number of fish that have survived to adulthood and are entering the exploitable stock in a given year.
Reference limit point / Limit reference point (LRP)
The limit reference point is a benchmark for stock status below which serious harm to the stock is occurring, but above the point where extinction is the primary concern. It marks the boundary between the Cautious and Critical zones in DFO’s Precautionary Approach framework. When a stock falls below its LRP, conservation becomes the priority: management actions must promote stock growth, and human-caused removals should be kept to as low as possible to support rebuilding.
Figure 3. Relationship between stock status and allowable removal rate under DFO’s Precautionary Approach framework. The framework consists of three zones: Critical, Cautious, and Healthy. The limit reference point (1) defines the threshold between the Critical and Cautious zones; the upper stock reference (2) defines the threshold between the Cautious and Healthy zones; and the removal reference (3) identifies the maximum acceptable removal rate. The figure illustrates that removal rates should decline as stock status worsens, with removals kept as low as possible when the stock is below the limit reference point.
Roe Fishery
The Roe Fishery – both gill net and seine vessels – is B.C.’s largest herring fishery and typically opens in early spring. This fishery targets female herring for their eggs (roe), harvesting fish before they have a chance to spawn. Because roe makes up only about 12% of a female herring’s biomass, most of the fish is used for other purposes after the eggs are removed. The roe is mostly exported overseas, with little benefit to Canadian food security. The remaining fish bodies, from both females and males, are often processed into fish meal and oil for uses like pet food, aquaculture feed, and fertilizer. In 2025/2026, nearly 80% (11,353 tonnes) of the Strait of Georgia’s approved 14,390 tonne harvest is allocated to this fishery.
While Spawn-on-Kelp is technically a commercial fishery also targeting roe, it is not managed as a part of the Roe Fishery by DFO. For more on Spawn-on-Kelp see below (definition 30).
Seine Fishery
A seine fishery deploys seine nets –large nets that hang vertically in the water with floats on the top edge and weights on the bottom – to catch fish. Seine fisheries actively surround and capture schools of fish, unlike stationary gear (like gill nets) that rely on fish swimming into them. The net is set in a circle (purse seine) or another pattern around the target aggregation, then the bottom is closed like a drawstring purse, or dragged along the seabed to trap fish, into a central “bag”.
Spawn-on-Kelp (SOK)
In a spawn-on-kelp (SOK) herring fishery, the product is roe (eggs) deposited on kelp blades and not the adult herring themselves. Kelp fronds are suspended where spawning is expected, then harvested with eggs attached. Similarly, spawn-on-bough uses branches (traditionally hemlock) that are placed in the water to collect herring eggs. This traditional Indigenous harvesting method, practiced by coastal First Nations for millenia, is ecologically sustainable and lower-impact than roe fisheries that kill fish. Because the adult herring are left alive, they can return to spawn again in future years.
Spawning biomass
Spawning biomass is the total weight of sexually mature fish in a stock that are capable of reproducing. Because it reflects the stock’s reproductive capacity, it is often used to assess stock status and, in some fisheries, to define management thresholds such as the Reference Limit Point (see definition 27).
Stock assessment
A stock is a population of one fish species within a specific area, serving as the basic unit for management. Stock assessment is the scientific process of collecting and analysing data – such as catches, surveys, and age structure – to estimate stock status and trends. It also predicts how the stock will respond to different management choices.
Special Use Fishery
The Special Use Herring Fishery harvests herring for bait and for food markets, serving personal, recreational, and commercial needs. It primarily occurs in the Strait of Georgia, but can happen anywhere permitted in the IFMP (see definition 17). The Special Use fishery is divided into five licence categories for different uses and products, including personal use, sport bait, commercial bait, domestic food and bait, and zoo or aquarium use. All bait licences are party-based and then assigned to an eligible registered commercial fishing vessel. This means the licence “belongs” to the party holding the eligibility, and is not automatically associated with one specific boat which is different from a vessel-based licence, where the eligibility is attached to the vessel itself.
Alongside the Food & Bait fishery, the Special Use fishery targets pre-spawning herring in fall and winter, catching both inshore resident fish and offshore migratory fish moving toward the coast. These pre-spawn catches supply herring to use as bait for other fisheries, feed for aquariums, and into products like fish meal and fish oil – for livestock, aquaculture feed, pet food, and fertilizer – and limited human consumption.
Total allowable catch (TAC)
The total allowable catch (TAC) is the total amount of catch that may be harvested from a stock over a specified time period to meet management objectives. It is often a percentage of the stock, measured by weight. TACs are based on stock assessments and policy targets and are typically subdivided into quotas for different fleets, gear types, or countries.
Validation
Catch validation is a program designed to monitor, record, and verify catches, particularly at landing. Validation involves an observer or validator confirming the landed fish weight; “total validated landings” are the sum of all such verified amounts. This process helps ensure that reported catches match actual landings.
Conclusion:
Now that you are equipped with fisheries terminology, you’re ready to dive deeper into our campaigns: