NWFSC Glossary - Northwest Fisheries Science Center

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ABC
	Allowable Biological Catch. A term that refers to the range of allowable catch for a species or species group. It is set each year by a scientific group. The ABC estimates are used to set the annual total allowable catch (TAC). See also TAC.
abiotic factor
	The physical, chemical, and other non-living components of the environment in which an organism lives. These factors include all aspects of climate, geology, and atmosphere that affect ecological systems. Compare biotic factor.
abundance
	The number of fish or other species of interest in a population.
abyssopelagic zone
	Abysso meaning "no bottom." This zone of the ocean begins 4,000 m below the surface of the ocean and extends down to the sea floor. It is home to a variety of unique species that are specially adapted to the inhospitable conditions that these depths create. Compare bathypelagic zone and mesopelagic zone.
ACE
	U.S. Army Corps of Engineers.
adaptation
	Any change in the structure or function of an organism that makes it better suited to its environment. For example, the torpedo body shape of a tuna allows for fast swimming in the open ocean.
adduct
	In physiology, to draw in toward the median axis of the body or an adjacent part or limb; in chemistry, a compound formed by the combination of two or more substances.
ADF&G
	Alaska Department of Fish and Game.
adipose fin
	A small fin on the fish's back near the tail; often removed on hatchery salmon in order to differentiate them from wild salmon.
AFSC
	Alaska Fisheries Science Center. One of six regional research centers of the National Marine Fisheries Service. See also NMFS.
air bladder
	An air-filled structure used by fish to maintain buoyancy and, in some species, to aid in respiration; also known as swim bladder.
alevin
	Newly hatched salmon with the yolk sack still attached.
ALL
	Aquatic lands lease.
allele
	One of the alternative forms of a particular gene. Each gene is comprised of two alleles, one inherited from the father and one from the mother. Within a population, however, many alleles may exist for one gene.
allopatric
	Occupying distinct geographical areas (and therefore unable to interbreed).
allozyme
	One of several forms of the same enzyme having electrophoretic mobilities and which corresponds to alternative alleles at the same genetic locus.
anadromous
	Of a fish species, migrating as a juvenile from fresh water to the ocean and then returning as an adult to spawn in fresh water; most Pacific salmon are anadromous; compare catadromous.
anal fin
	The single fin situated on the midline of the fish behind the anus.
ANOVA
	Analysis of the variance. A group of statistical procedures.
aquaculture
	The commercial growing of marine or freshwater plants or animals in water.
ASCII
	American Standard Code for Information Interchange.
ASMFS
	Atlantic States Marine Fisheries Commission. Serves as a deliberative body of the Atlantic coastal states, coordinating the conservation and management of nearshore fishery resources, including marine, shell, and anadromous species.
ASP
	Amnesiac shellfish poisoning. The original name given to domoic acid poisoning, one symptom of which is severe short-term memory loss. See also domoic acid.
assay
	Experimental test or analysis.
autocorrelation
	The correlation of a variable with itself over time.
autotroph
	An organism that synthesizes organic molecules from inorganic starting materials through photosynthesis or chemosynthesis. Autotrophs are ecologically important as primary producers as they ultimately provide energy for all heterotrophic organisms. See also chemosynthesis and photosynthesis; compare heteroptroph.
B
	The weight (biomass) of a group of fish necessary to produce maximum sustainable yield (MSY).
bacteriophage
	A virus that invades and destroys (eats) host bacteria.
barbell
	A fleshy, flap like or whisker like appendage (very small and hard to see on some minnows) found near the mouth. Used as a sensory organ. A good example is on the shovelnose sturgeon.
bathypelagic zone
	The zone of the ocean that extends from 1,000 m to 4,000 m below the surface of the ocean. Compare abyssopelagic zone and mesopelagic zone.
BCSGA
	British Columbia Salmon Growers Association (Canada).
benthic
	Or, related to, or living in the soil-water interface of a stream, lake, or ocean; bottom dwelling. See also substrate; compare nekton.
bimodal distribution
	Indicating two length groups within which individuals are most abundant, possibly with other less abundant length groups around them.
biodiversity
	The variation in life on earth reflected at all levels, from various ecosystems and species to the genetic variation within a species. See also ecosystem diversity, genetic diversity, and species diversity.
bioluminescence
	Meaning living (bio) light (luminescence). The light produced by living organisms and the emission of such biologically produced light. Also commonly referred to as "phosphorescence."
biotic factor
	A living component of the environment which arises from and affects living organisms (distinct from physical factors). For example, the interaction between predators and prey is a biotic interaction. Compare abiotic factor.
biotoxins
	Neuropoisons that can cause illness or death in humans and animals that consume products from the sea.
BKD
	Bacterial kidney disease.
BMP
	Best management practice.
BMSY
	The weight (biomass) of a group of fish necessary to produce maximum sustainable yield (MSY).
body depth
	The greatest vertical distance between the midline of the back and the midline of the belly; the "height" of the fish.
body width
	The greatest distance from one side of the body to the other.
broodstock
	A group of mature fish that is kept separate and used for producing fry.
BRT
	Biological Review Team. A team of scientists formed to conduct a status review of a species.
catadromous
	Migrates as a juvenile from salt water to fresh water and then returns as an adult to spawn in salt water; some eels are catadromous, but most Pacific salmon are anadromous, which is the opposite. Compare anadromous.
cetacean
	Of the order Cetacea, which includes all whales. The three suborders are the toothed whales or Odontoceti (killer whales, dolphins, porpoises, beluga whales, and sperm whales), the baleen whales or Mysticeti (blue whales, humpback whales, gray whales, and right whales), and the Archaeoceti (which all are now extinct).
CFMC
	Caribbean Fishery Management Council.
CFR
	Code of Federal Regulations.
chemosynthesis
	The process whereby chemical energy is used to make organic compounds from inorganic compounds. One example is the oxidation of ammonia to nitrite by nitrifying bacteria. Compare photosynthesis and primary production.
Chinook salmon
	Species Oncorhynchus tshawytscha. See also Pacific salmon.
chum salmon
	Species Oncorhynchus keta. See also Pacific salmon.
coded-wire tag
	Miniature radio frequency electronic tags that are placed in fish and provide a means for researchers to track fish movements and study their behavior.
coho salmon
	Species Oncorhynchus kisutch. See also Pacific salmon.
community
	A naturally occurring group of plants and animals that live within a certain environment and interact with each other. Communities are often defined by a dominant species (e.g., kelp forest community) or the major physical characteristics of the area (e.g., mud flats).
congener
	An organism of the same class, group, or genus as another (from the Latin for "same race").
conservation biology
	A field of science that deals with threats to biodiversity. The goals of conservation biology are to investigate human impacts of biodiversity and to develop approaches to prevent extinction through stewardship of entire biological communities.
Conservation Biology Division
	One of six divisions under the Science Director's Office of the Northwest Fisheries Science Center. See also NWFSC.
contaminants
	Chemical pollution in coastal areas near urban centers that may be responsible for a variety of deleterious biological effects in aquatic species.
convergent evolution
	The development of similar structures in organisms that do not share a recent common ancestor (e.g., the eyes of squid, flies, and humans). See also evolution; compare divergent evolution.
CPUE
	Catch per unit of effort. The number of fish caught by an amount of effort. Typically, effort is a combination of gear type, gear size, and length of time gear is used. Catch per unit of effort is often used as a measurement of relative abundance.
CRI
	Cumulative Risk Initiative. CRI is an ongoing effort of the NWFSC that assesses salmonid population trends and the impact of various actions on those trends.
cytokine
	A class of proteins that are released by immune system cells to stimulate an immune response.
DDT
	Dichlorodiphenyltrichloroethane. 1) The insecticide C14H9Cl5, 2) any of a group of similar chemicals.
decomposer
	An organism that gains energy by breaking down the final remains of living things. Predominantly bacteria and fungi, decomposers are important in freeing the last of minerals and nutrients from organics and recycling them back into the food web. See also decomposition; compare detrivore.
decomposition
	The biochemical process where biological materials are broken down into smaller particles and eventually into basic chemical compounds and elements. See also decomposer.
demersal
	Sinking to or inhabiting the ocean bottom.
detritus
	Dead organic matter of plants or animals. See also detrivore.
detrivore
	An organism that feeds on large bits of dead and decaying organic matter. What detrivores leave behind is used by decomposers. Crabs and seabirds are examples of detrivores. See also detritus; compare decomposer.
DFO
	Department of Fisheries and Oceans Canada.
diatoms
	Microscopic algae with plate-like structures composed of silica.
divergent evolution
	The evolution of one species to a number of different forms. See also evolution; compare convergent evolution.
diversity
	Genetic variations that allow a population to use a wider array of environments, protect against short-term spatial or temporal changes in the environment, and survive long-term environmental changes.
DOC
	U.S. Department of Commerce. Mission includes creating an infrastructure that promotes economic growth, technological competitiveness, and sustainable development. NOAA is under the DOC and NMFS is under NOAA.
DOI
	U.S. Department of the Interior.
domestic selection
	Adaptation of a population to the hatchery environment, which may diminish adaptation of the population to the natural environment.
domestication
	1) Captivity (e.g., being reared in a hatchery), 2) Genetic, physiological, or bevahioral changes that may occur in captivity.
domoic acid
	A water-soluble amino acid, domoic acid is a deadly neurotoxin produced by some algae (from Japanese domoi = seaweed, in which it is sometimes concentrated). See also ASP.
dorsal
	Upper side of a fish's body (opposite of ventral).
EAO
	Environmental Assessment Office (Canada).
ecosystem
	A community of plants, animals, and other organisms that are linked by energy and nutrient flows and that interact with each other and with the physical environment. Rain forests, deserts, coral reefs, and grasslands are examples of ecosystems.
ecosystem diversity
	The diversity of biological communities and their physical environments. Diversity is determined by the species composition, physical structure, and processes within an ecosystem. This is the highest level of biodiversity. See also biodiversity, genetic diversity, and species diversity.
ecotoxicology
	The scientific study of harmful effects caused by manmade chemicals to the natural environment.
EEZ
	Exclusive economic zone. All waters from the seaward boundary of coastal states (typically 3 nautical miles) out to 200 nautical miles.
EFCL
	Electronic fish catch logbook.
effluent
	Industrial or urban waste discharged into the environment.
electrophoretic
	Of or relating to electrophoresis, which is a method of separating substances, especially proteins, and analyzing molecular structure based on the rate of movement of each component in a colloidal suspension while under the influence of an electric field.
ELISA
	Enzyme linked immunosorbent assay. A sensitive immunological test that uses an enzyme as a marker for the presence of a specific protein.
endangered
	According to the U.S. Endangered Species Act of 1973, a species or ecosystem that is so reduced or delicate that it is threatened with or on the verge of extinction. See also ESA; compare threatened.
endemic
	An animal or plant species that naturally occurs in only one area.
energetics
	The study of the flow and transformation of energy.
Environmental Conservation Division
	One of six divisions under the Science Director's Office of the Northwest Fisheries Science Center. See also NWFSC.
EPA
	U.S. Environmental Protection Agency.
epipelagic zone
	See photic zone.
EPR
	Eggs-per-recruit. The average number of eggs produced by an individual fish that has been recruited, that is, moved into a certain class, such as the spawning class or fishing-size class. Used as an index of abundance.
ERD
	Entity relationship diagram.
ESA
	U.S. Endangered Species Act 1973. Its purpose is to "provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved." See also endangered and threatened.
escapement
	The portion of an anadromous fish population that escapes commercial and recreational fisheries and reaches its freshwater spawning grounds.
estuary
	An arm of the sea that extends inland to meet the mouth of a river.
ESU
	Evolutionarily significant unit. A population segment (e.g., Redfish Lake sockeye) equivalent to the "distinct population" referred to in the U.S. Endangered Species Act of 1973.
eutrophication
	Enrichment of a water body with nutrients, resulting in excessive growth of phytoplankton, seaweeds, or vascular plants, and often depletion of oxygen.
evolution
	The process by which a species' structural and behavioral characteristics change over many generations, sometimes in response to changes in environmental conditions. New species develop in this way. For example, scientists believe that whales gradually evolved from land animals. See also convergent evolution and divergent evolution.
F0.1
	The point on the spawning per recruit curve at which the level of spawning per recruit is 35% or 40% of the maximum.
F20%
	The level of fishing mortality that results in a spawning potential ratio of 20% of the maximum.
F25%
	The level of fishing mortality that results in a spawning potential ratio of 25% of the maximum.
F30%
	The level of fishing mortality that results in a spawning potential ratio of 30% of the maximum.
F40%
	The level of fishing mortality that results in a spawning potential ratio of 40% of the maximum.
FABC
	The level of fishing mortality that results in the allowable biological catch.
FAO
	United Nations Food and Agriculture Organization, Rome.
FDA
	U.S. Food and Drug Administration.
fertilization
	The joining or fusion of the male gamete (sperm) and the female gamete (egg) to form a zygote during sexual reproduction. See also gamete and zygote.
fin ray
	A slender, rod-shaped structure that supports the membranes of the fins of a fish. There are two types of rays, soft rays and spines. Soft rays are jointed, often branched, and flexible near their tips. Spines are unjointed, unbranched, and usually sharp at the tip and stiff along the shaft.
Fish Ecology Division
	One of six divisions under the Science Director's Office of the Northwest Fisheries Science Center. See also NWFSC.
fishery
	1) One or more stocks of fish that can be treated as a unit for purposes of conservation and management and that are identified on the basis of geographic, scientific, technical, recreational, or economic characteristics or method of catch; 2) any fishing for such stocks.
Fishery Resource Analysis and Monitoring Division
	One of six divisions under the Science Director's Office of the Northwest Fisheries Science Center. See also NWFSC.
fishing mortality rate
	A measurement of the rate of removal of fish from a population by fishing. Fishing mortality rate can be reported as either annual or instantaneous. Annual mortality is the percentage of fish dying in one year. Instantaneous mortality is that percentage of fish dying at any one point in time.
FMAX
	The level of fishing mortality that results in the greatest yield from the fishery.
FMP
	Fishery management plan. A plan to achieve specified management goals for a fishery prepared under the authority of the Magnuson-Stevens Fishery Conservation and Management Act of 1976.
FMSY
	The level of fishing mortality that results in the maximum sustainable yield.
FOF
	The level of fishing mortality defined as overfishing.
food chain
	A linear sequence of organisms that exists on successive trophic levels within a natural community, through which energy is transferred by feeding. Primary producers capture energy from the environment (through photoynthesis or chemosynthesis) and form the base of the food chain. Energy is then passed to primary consumers (herbivores) and on to secondary and tertiary consumers (carnivores and top carnivores) (e.g., phytoplankton are consumed by zooplankton are consumed by herring are consumed by salmon are consumed by killer whales). Once they die, these organisms are in turn consumed and their energy transferred to detrivores and decomposers. See also primary consumer and secondary consumer.
food web
	A nonlinear network of feeding between organisms that includes many food chains, and hence multiple organisms on each trophic level. For example, both sharks and tuna eat herring, and sharks also eat tuna.
fry
	Young fish that are able to swim and catch their own food.
gamete
	A mature reproductive cell that is capable of fusing with another gamete of the opposite sex to form a zygote. Male gametes are typically known as sperm and female gametes are typically known as eggs. See also fertilization and zygote.
GDP
	Gross domestic product.
GDU
	Genetic diversity unit.
generalist
	A species that can live in many different habitats and can feed on a number of different organisms. For example, shore crabs on the Pacific coast live in a wide variety of habitats, such as mud, sand, and rock, and feed on everything from algae growing on rocks to invertebrates to detritus. Compare specialist.
genetic diversity
	The genetic variation that occurs within a population or species. For example, there are several different color dog whelk shells and ochre sea stars. See also biodiversity, ecosystem diversity, and species diversity.
genotype
	The genetic makeup of an organism. The actual appearance of an individual (the phenotype) depends on the interaction between different forms (or alleles) of genes and between the genotype and the environment. Compare phenotype.
GESAMP
	Joint Group of Experts on Scientific Aspects of Marine Environmental Protection (United Nations).
gill arches
	The series of curved, bony structures lying beneath the gill cover of a fish that support the gill rakers and gill filaments.
gill cover
	The large, flat bone on the side of the head of a fish covering the gills.
gill rakers
	Knob or comb like projections on the front edge of the gill arch. They serve to protect and clean the gill filaments.
gillnet
	A net set upright in the water to catch fish by entangling their gills in its mesh.
GIS
	Geographic information system.
GLP
	Good laboratory practice.
GM
	genetically modified.
GMFMC
	Gulf of Mexico Fishery Management Council.
GMO
	Genetically modified organism.
GPS
	Global positioning system.
GSMFC
	Gulf States Marine Fisheries Commission. Serves as a deliberative body of the Gulf of Mexico coastal states, coordinating the conservation and management of nearshore fishery resources, including marine, shell, and anadromous species.
HAB
	Harmful algal bloom.
habitat
	The immediate space where an animal or plant lives and has food, water, and protection. Habitat loss, which includes the destruction, degradation, or fragmentation of habitats, is the primary cause of decreasing biodiversity.
HACCP
	Hazard analysis critical control point.
HAH
	High molecular weight aromatic hydrocarbon, also halogenic aromatic hydrocarbon. See also LAH.
hatchery
	An artificial propagation facility designed to produce fish for harvest or spawning escapement. A conservation hatchery differs from a production hatchery in that it specifically seeks to supplement or restore naturally spawning populations. Salmon hatcheries typically spawn adults in captivity and raise the resulting progeny in freshwater for release into the natural environment. In some cases, fertilized eggs are outplanted (usually in hatch boxes), but it is more common to release fry (young juveniles) or smolts (juveniles that are physiologically prepared to undergo migration into salt water).
herbivore
	A plant-eating animal. Sea urchins are a good example of a marine herbivore as they feed on kelp. See also heterotroph and primary consumer.
hermaphrodite
	An animal that has both male and female reproductive organs. Nudibranchs (sea slugs) are a good example of an hermaphrodite.
heterotroph
	An organism that is unable to synthesize organic compounds (and thus its energy) from the environment and therefore fulfils its energy requirements by feeding on other organisms or organic matter. See also herbivore; compare autotroph.
HGMP
	Hatchery and genetic management plan.
histopathology
	The microscopic study of disease in tissue.
HMS
	Highly migratory species. The Highly Migratory Species Management Division of NMFS develops fishery policies designed to manage any highly migratory species (e.g., tuna species, marlin, oceanic sharks, sailfishes, and swordfish) fishery that is within the geographical authority of more than one fishery management council.
homogeneous
	Similar or uniform structure or composition throughout.
hormone
	A chemical created in one organ by the endocrine system and transported by the bloodstream to other organs, where it has a stimulating effect.
HPA
	Hydraulic project approval.
HTRQ
	Hours to reach quota. A measure of fishing efficiency.
imprinting
	The process through which young fry memorize details about their home streams. As adult spawners, they use this knowledge to find their way back.
IMS
	Internet map service.
INAD
	Investigational new animal drug.
inorganic
	Part of or derived from nonbiological material. A chemical compound that does not include a carbon chain. Compare organic.
introduced species
	An organism that has been brought into an area, usually by humans, where it does not normally occur. Introduced species often compete with and cause problems for native species. Introduced species are also called exotic, nonnative, and alien species. See also invasive species and native species.
invasive species
	An introduced species that out-competes native species for space and resources. Scotch Broom is an invasive species that out-competes local vegetation and results in a monoculture, and hence a decrease in local diversity. See also introduced species and native species.
iteroparous
	Producing offspring in successive, such as annual or seasonal, batches.
IV&V
	Independent validation and verification.
jack
	Salmon males that mature early.
jill
	Salmon females that mature early.
JSA
	U.S. Joint Subcommittee on Aquaculture.
kelt
	A salmon after spawning.
keystone predator
	The dominant predator or the top predator that has a major influence on community structure. For example, sea otters are a keystone predator in kelp beds. Sea otters eat urchins that feed on kelp which house a huge diversity of other organisms. If sea otter populations are lowered in an area, the kelp beds are generally reduced and urchin barrens appear.
keystone species
	A species that has a major influence on community structure.
killer whale
	Species Orcinus orca. The three types of killer whales in the North Pacific are residents, transients, and offshores. Resident killer whales forage primarily for fish in relatively large groups in coastal areas. Transient killer whales, whose range extends over a broader area, primarily hunt marine mammals. Little is known about offshore killer whales, but their prey does include fish. The Southern Resident killer whale population consists of three pods that reside primarily in Puget Sound, the Strait of Juan de Fuca, and the Strait of Georgia. Northern Residents and the closely related Alaska Residents occupy adjacent ranges in British Columbia and Alaska.
kingdom
	The broadest taxonomic classification for plants and animals. The descending categories are phylum, class, order, family, genus, and species.
kokanee
	A resident form of sockeye salmon (Oncorhynchus nerka) that spends its entire life in freshwater.
LAH
	Low molecular weight aromatic hydrocarbon. See also HAH.
lambda
	A statistical term usually referring to population growth.
lateral line
	A series of sensory tubes and pores that extend from the head of a fish along the side of the body.
lateral line scales
	Fish scales that bear the pores and tubes of the lateral line.
leucocyte
	White corpuscle capable of digesting harmful bacteria and fungi, among others.
limnology
	The scientific study of the life and phenomena of fresh water, especially lakes and ponds.
lipid
	A broad class of fatty, oily, or waxy compounds that form a major part of the structure of most living things.
littoral
	Living in nearshore water or the intertidal zone (between high and low tide).
lymphocyte
	A type of white cell found in the blood or lymph tissue.
macrophage
	A large phagocytic cell.
MAFMC
	Mid-Atlantic Fishery Management Council.
mesopelagic zone
	Also called the twilight zone of the ocean, this area from 200 m to 1,000 m in depth is bordered by the photic zone above and darkness below. It is in this zone where animals first begin to exhibit bioluminescence. Compare abyssopelagic zone and bathypelagic zone.
MFMT
	Maximum fishing mortality threshold. The level or rate of fishing mortality that, if exceeded, will result in overfishing and jeopardize the capacity of a stock or stock complex to produce maximum sustainable yield on a continuing basis.
milt
	The milky sperm of a male fish.
MLLW
	Mean lower low water.
morphology
	The form and structure of an organism, in particular its outside features.
MSP
	Maximum spawning potential. See also SPR.
MSST
	Minimum stock size threshold. The minimum size of the stock or stock complex that is required to produce maximum sustainable yield (MSY), below which the stock would be considered overfished. The threshold should equal whichever of the following is greater: half the MSY stock size or the minimum stock size at which rebuilding to the MSY level would be expected to occur within 10 years if the stock or stock were exploited at the maximum fishing mortality threshold.
MSY
	Maximum sustainable yield. The largest long-term average catch or yield that can be taken from a stock or stock complex under prevailing ecological and environmental conditions.
multivariate analysis
	A set of techniques used when variation in several variables must be studied simultaneously.
NADP
	National Aquaculture Development Plan.
NAICS
	North American Industrial Classification System. Replaced SIC (standard industrial code) classification system in 1997. A numerical system for classifying industries and business types; a cooperative effort between Canada, the United States, and Mexico.
native species
	A species that occurs naturally in an area (i.e., is not introduced). Compare introduced species and invasive species.
natural selection
	The main mechanism of evolutionary change. In a given population of organisms, there are heritable traits that enable some members to contribute a larger number of offspring than others. If these offspring also have a greater reproductive success, then the genetic composition of the population is altered, thus evolution. See also selection pressure.
NATURES
	Natural Rearing Enhancement System.
NEFMC
	New England Fishery Management Council.
NEFSC
	Northeast Fisheries Science Center. One of six regional research centers of the National Marine Fisheries Service. See also NMFS.
nekton
	Pelagic organisms that are free-swimming and so whose movements are independent of the tides, currents, and waves. Such animals include fish, whales, squid, crabs, and shrimps. The distribution of nekton is limited by temperature and nutrient supply and decreases with decreasing depth. Compare benthic and plankton.
NMFS
	National Marine Fisheries Service (or NOAA Fisheries Service). NMFS, which is a division of NOAA, has its headquarters in Silver Spring, Maryland, and has a regional office and a science center in each of six regions. The regional offices provide management and policy leadership. The science centers provide scientific research on which resource management policies are based. The six regional research centers are Alaska Fisheries Science Center (AFSC), Northeast Fisheries Science Center (NEFSC), Northwest Fisheries Science Center (NWFSC), Pacific Islands Fisheries Science Center (PIFSC), Southeast Fisheries Science Center (SEFSC), and Southwest Fisheries Science Center (SWFSC).
NOAA
	National Oceanic and Atmospheric Administration; part of the U.S. Department of Commerce.
nonrenewable resource
	A resource that cannot be replenished by natural processes, at least not within a relatively short period of time. Fossil fuels are nonrenewable resources. Compare renewable resource.
NPAFC
	North Pacific Anadromous Fish Commission.
NPDES
	National Pollution Discharge Elimination System permit.
NPFMC
	North Pacific Fishery Management Council.
NSGCP
	National Sea Grant College Program (NOAA).
NSSP
	National Shellfish Sanitation Program.
nucleotide
	The basic structural component of nucleic acids such as RNA and DNA.
null hypothesis
	The assumption that an observed difference is due to chance rather than some other, hypothesized causal factor.
NWFSC
	Northwest Fisheries Science Center. One of six regional research centers of the National Marine Fisheries Service. See also NMFS.
NWIFC
	Northwest Indian Fisheries Commission.
OAR
	Office of Oceanic and Atmospheric Research (NOAA).
observers
	Contractors sponsored by the federal government who observe and record fisheries onboard catch activity.
ODFW
	Oregon Department of Fish and Wildlife.
ODIN
	Official Documentation and Information from Norway.
oligonucleotide
	A polymer chain of several nucleotides.
Operations, Management, and Information Division
	One of six divisions under the Science Director's Office of the Northwest Fisheries Science Center. See also NWFSC.
operculum
	Gill cover.
organic
	Part of or derived from living organisms; also a chemical compound that contains carbon as an essential component. Compare inorganic.
ORHAB
	Olympic region harmful algal bloom.
otolith
	Ear bone of a fish. Otoliths often show seasonal or annual rings that can be used to determine age.
outbreeding
	Mating individuals from different populations.
over-consumption
	The use of resources at a rate that exceeds the ability of natural processes to replace them.
OY
	Optimum yield. The amount of fish that: 1) will provide the greatest overall benefit to the nation, particularly with respect to food production and recreational opportunities, and taking into account the protection of marine ecosystems; 2) is prescribed on the basis of the maximum sustainable yield from the fishery, as reduced by any relevant economic, social, or ecological factors; and 3) in the case of an overfished fishery, provides for rebuilding to a level consistent with producing the MSY in such fishery.
PacFIN
	Pacific Fisheries Information Network.
Pacific salmon
	The five species of Pacific salmon are Chinook salmon (Oncorhynchus tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), pink salmon (O. gorbuscha), and sockeye salmon (O. nerka). Also in the genus Oncorhynchus is the steelhead (O. mykiss), an anadromous salmonid.
PAH
	Polycyclic aromatic hydrocarbon. One of more than 100 chemicals that are produced by the combustion of wood, tar, and other materials. PAHs can persist in the environment from days to years, depending on their form and local conditions; some are carcinogenic.
paired fins
	The pectoral and pelvic fins of a fish.
parr
	Juvenile salmon with large dark spots on their sides for camouflage. Salmon parr usually live in freshwater for 1 to 2 years.
pathogens
	Disease producing organisms.
pathology
	The scientific study of the nature of disease and its causes, processes, development, and consequences.
PCB
	Polychlorinated biphenyl. A group of pollutants that accumulates in animal tissue.
PCHB
	Pollution Control Hearings Board (Washington State).
PDF
	Probability density function. A description of the probability that a variable takes a specified value.
pectoral fins
	The farthest forward or uppermost of the paired fins.
pelagic
	Refers to plants and animals that live in the water column or in the open waters of the ocean rather than the ocean floor. Life is found throughout the pelagic zone, however it is more concentrated at shallower depths. Pelagic organisms are further divided into plankton and nekton. Compare benthic (epipelagic: living in the upper or photic layer between 0 and 200 m; mesopelagic: living between 200 and 1,000 meters).
pelvic fins
	The paired fins located beneath or behind the pectoral fins.
pesticides
	Chemical products used to reduce or eliminate unwanted organisms, regarded as pests. Pesticides are often used on gardens, agricultural land, roadsides, and golf courses to eliminate species considered undesirable or damaging.
PFMC
	Pacific Fishery Management Council.
phage, bacteriophage
	A virus that invades and destroys (consumes) host bacteria.
phagocyte
	A cell that engulfs or eats waste material or invading organisms. White blood cells are an example.
pharyngeal arches
	In fish, the pair of curved bones located in the throat that bear the throat teeth.
phenotype
	The physical appearance of an individual that is the result of that individual's genotype and the interaction of the genotype with the environment during development. Hence, individuals with the same genotype may have different phenotypes in different environments. Compare genotype.
phosphoresence
	See bioluminescence.
photic zone
	The surface layer of the ocean that is penetrated by sunlight. The photic zone is the layer of the ocean that has been explored the most as it is relatively easy to access with conventional diving equipment. In the photic zone, phytoplankton flourish and it is where the fish, marine mammals, and marine invertebrates most familiar to people are found. Light can penetrate down to approximately 200 m which marks the end of the photic zone. Also referred to as the sunlight zone or the epipelagic zone. See epipelagic zone.
photosynthesis
	A chemical process whereby plants and algae use the sun's energy to make sugars (organic compounds) from carbon dioxide and water (inorganic compounds). See also autotroph and primary production; compare chemosynthesis.
physiology
	The biological study of the functions of living organisms and their parts.
phytoplankton
	Literally "wandering plant." The plant and algae component of plankton and the primary producers of almost all marine food webs. Compare zooplankton.
PIFSC
	Pacific Islands Fisheries Science Center. One of six regional research centers of the National Marine Fisheries Service. See also NMFS.
Pink salmon
	Species Oncorhynchus gorbuscha. See also Pacific salmon.
pinniped
	Of or belonging to the Pinnipedia, a suborder of carnivorous aquatic mammals that includes seals, walruses, and similar animals having finlike flippers as organs of locomotion.
PIT tag
	Passive integrated transponder tag.
plankton
	Pelagic organisms that float through the water column, not attached to any substrate and unable to move against the currents and tides. Plankton can be further divided into phytoplankton and zooplankton, meroplankton and holoplankton. Compare nekton.
PNWFHPC
	Pacific Northwest Fish Health Protection Committee.
population
	The number of individuals of a particular species that live within a defined area.
predator
	An animal that hunts and kills other animals for food.
prey
	An animal that is used by other animals for food.
primary consumer
	A heterotrophic, herbivorous organism that feeds directly on a primary producer. Urchins are a primary consumer as they feed on kelp. See also heterotroph and food chain; compare secondary consumer.
primary production
	Synthesis of organic matter by plants, which is the main source of energy and nutrition for other consumers in the ecosystem (e.g., herbivores). See also chemosynthesis and photosynthesis.
protein
	A large class of nitrogenous organic molecules constructed from amino acids. They are essential to the functioning of all living tissue, and include large subclasses of molecules such as enzymes and hormones.
PSEP
	Puget Sound Estuary Protocols.
PSGA
	Puget Sound Gillnetters Association.
PSMFC
	Pacific States Marine Fisheries Commission.
PSP
	Paralytic shellfish poison.
PSWQAT
	Puget Sound Water Quality Action Team.
quadrat
	An ecological sampling unit that consists of a square frame of known area. The quadrat is used for quantifying the number or percent cover of a given species within a given area. See also transect.
random variable
	A variable whose values are random but whose statistical distribution is known.
RCW
	Revised Code of Washington. A compilation of all current Washington State laws; Washington Administrative Code (WAC) is the compilation of regulations written to enforce state laws.
recovery
	Improvement in the status of a listed species (as threatened or endangered under the U.S. Endangered Species Act of 1973) to the point at which listing is no longer appropriate.
recruitment
	1) Entry of new fish into a population, whether by reproduction or immigration; 2) Addition of new individuals to the fished component of a stock (because they have acquired the size, age, or location that makes them part of it).
redd
	A salmon nest, dug out of the gravel in the stream bed by the adult female.
regression analysis
	The use of regression to make quantitative predictions of one variable from the values of another.
renewable resource
	A resource that can be replenished through natural processes within a human life span, if it is soundly managed. Compare nonrenewable resource.
Resource Enhancement and Utilization Technologies Division
	One of six divisions under the Science Director's Office of the Northwest Fisheries Science Center. See also NWFSC.
restoration
	In the strictest sense, returning the ecosystem to some predisturbed condition; some practitioners call that full restoration. The term is often used more generically to mean partial restoration, enhancement, or rehabilitation of the ecosystem.
riparian
	Related to, living on, or located on the bank of a river, lake, or tidewater. Part of the landscape that exerts a direct influence on stream channels or lake margins and the water or aquatic ecosystems.
RSRP
	Recovery Science Review Panel.
SAFE
	Stock Assessment and Fishery Evaluation. A document or set of documents that provide fishery management councils with a summary of the most recent biological condition of species in a fishery management unit, and the social and economic condition of the recreational and commercial fishing interests and the fish processing industries. It summarizes, on a periodic basis, the best available scientific information concerning the past, present, and possible future condition of the stocks and fisheries being managed under federal regulation.
SAFMC
	South Atlantic Fishery Management Council.
SARC
	Stock Assessment Review Committee.
scales
	Thin, small, overlapping plates that protect a typical fish's body. Scales grow in regular concentric patterns and can be used to determine the age and life history of a fish.
SCAN
	Scientific Committee on Animal Nutrition (European Union).
Science Director's Office
	Provides overall leadership and coordination for the Northwest Fisheries Science Center's six divisions.
screens
	Used at Columbia River hydroelectric dams to guide fish away from turbine intakes and into juvenile bypass systems.
secondary consumer
	A heterotrophic, carnivorous organism that feeds on a primary consumer. Herring feeding on zooplankton are an example of a secondary consumer. See also food chain, heterotroph, and primary consumer.
sediment
	Solid fragments of inorganic or organic material that come from the weathering of rock and are carried and deposited by wind, water, or ice.
SEFSC
	Southeast Fisheries Science Center. One of six regional research centers of the National Marine Fisheries Service. See also NMFS.
selection pressure
	A measure of the effectiveness of natural selection in altering the genetic composition of a population. See also natural selection.
semelparous
	Having only one reproductive or spawning period and dies after spawning.
sensory canal
	A branch of the lateral line that extends into the head of some fishes.
SEPA
	State Environmental Policy Act (Washington).
slope survey
	Bottom trawl, acoustic, or hook-and-line survey designed to provide information on distribution and abundance of demersal species and other biological resource information.
SMA
	Shoreline Management Act (Washington).
smolt
	Young salmon, migrating downstream from freshwater to saltwater. When parr become smolts, they lose their spots and turn silvery.
smoltification
	A suite of physiological, morphological, biochemical, and behavioural changes, including development of the silvery color of adults and a tolerance for seawater, that take place in salmonid parr as they prepare to migrate downstream and enter the sea.
sockeye salmon
	Species Oncorhynchus nerka. See also Pacific salmon.
soft dorsal
	A dorsal fin containing only soft rays, or the soft rayed hind part of the dorsal fin if both spines and soft rays are present (as in perches).
specialist
	A species with a very narrow range in habitat or food requirements. For example, the marbled murrelet nests in old-growth forests on thick branches high up in the forest canopy. Compare generalist.
speciation
	The evolution of one or more species from an existing species.
species
	A group of organisms that differs from all other groups of organisms and that is capable of breeding and producing fertile offspring. Compare kingdom.
species abundance
	The total number of individuals of a species within a given area or community. Compare species richness.
species diversity
	A measure of both species abundance and species richness. An area that has a large number of species and many representative individuals from each species is more diverse than an area that has only a single species. See also biodiversity, ecosystem diversity, and genetic diversity.
species richness
	The number of different species that exist within a given area or community. Compare species abundance.
SPR
	Spawning potential ratio. The number of eggs that could be produced by an average recruit in a fished stock, divided by the number of eggs that could be produced by an average recruit in an unfished stock. SPR can also be expressed as the spawning stock biomass per recruit (SSBR). See also MSP.
SSB
	Spawning stock biomass. The total weight of the fish in a stock that are old enough to spawn.
SSBR
	Spawning stock biomass per recruit. The spawning stock biomass divided by the number of recruits to the stock, or how much spawning biomass an average recruit would be expected to produce.
SSC
	Scientific and Statistical Advisory Committee. A committee composed of scientific and technical individuals providing advice to a fishery management council.
steelhead
	Species Oncorhynchus mykiss, an anadromous salmonid. See also Pacific salmon.
stochastic
	Probabilistic or involving probabilities, chance, or random variables.
stranding
	To drive or run ashore or aground.
straying
	To wander from a direct course, deviate, or go out of the way, as when a spawning adult salmon returns to a stream other than its natal stream within a basin.
substrate
	The material upon or within which a plant or animal live or grows (e.g., rocky or sandy substrate). See also benthic.
sustainable
	A way of life in which human needs are met without diminishing the ability of other people, wild species, or future generations to survive.
SWFSC
	Southwest Fisheries Science Center. One of six regional research centers of the National Marine Fisheries Service. See also NMFS.
swim bladder
	A sac inside the salmon's body by which the fish can control buoyancy and which can also be used for respiration, also known as air bladder.
symbiosis
	An interaction between two different species where either both, one or neither of the organisms benefit from the relationship. Many symbiotic relationships are obligatory (e.g., tropical reef building corals and their algal symbiont, also licens which are an alga and a fungus).
sympatric
	Occupying the same space but without interbreeding, as with closely related but distinct species.
systematics
	The area of biology that deals with the diversity of living organisms, their relationships to each other through evolution, and their classification. Can also be referred to as taxonomy.
TAC
	Total allowable catch. The annual recommended or specified regulated catch for a species or species group. The regional fishery management council sets the TAC from the range of acceptable biological catch (ABC). See also ABC.
taxonomy
	The theory and practice of describing, naming, and classifying plants and animals. See also systematics.
thermocline
	The often sharply defined boundary between surface water and deeper, cooler water.
threatened
	According to the U.S. Endangered Species Act of 1973, a species likely to become endangered if limiting factors are not reversed. See also ESA; compare endangered.
transect
	A straight line placed on the ground along which ecological measurements are taken. If an ecologist wanted to sample the diversity of intertidal organisms in the intertidal, transects would be placed perpendicular to the shore and samples would be taken at predetermined interval lengths. See also quadrat.
trophic
	Concerning feeding habits, food chains, or nutrition.
trophic levels
	The energy levels or steps in a food chain or food web.
TRT
	Technical Recovery Team. The TRT establishes biologically based ESA recovery goals for listed salmonids within a given recovery domain. Members serve as science advisors to the recovery planning phase.
USCG
	U.S. Coast Guard.
USDA
	U.S. Department of Agriculture.
USFWS
	U.S. Fish and Wildlife Service.
USOFR
	U.S. Office of Federal Regulations.
ventral
	Underside, opposite of dorsal.
VMS
	Vessel monitoring system.
VSP
	Viable salmonid population. An independent population of any Pacific salmonid (genus Oncorhynchus) that has a negligible risk of extinction due to threats from demographic variation (random or directional), local environmental variation, and genetic diversity changes (random or directional) over a 100-year time frame.
WAC
	Washington Administrative Code. A current compilation of Washington State regulations.
water cycle
	The continuous circulation of water from the atmosphere to the earth, including the ocean, and back to the atmosphere through condensation, precipitation, evaporation, and transpiration.
watershed
	The region draining into a river, river system, or other body of water.
WDA
	Washington Department of Agriculture.
WDF
	Washington Department of Fisheries (before 1991).
WDFW
	Washington Department of Fish and Wildlife.
WDNR
	Washington Department of Natural Resources.
WDOE
	Washington Department of Ecology.
WFGA
	Washington Fish Growers Association.
WHO
	United Nations World Health Organization.
WPFMC
	Western Pacific Fishery Management Council.
WRAC
	Western Regional Aquaculture Center.
WSGP
	Washington Sea Grant Program.
yolk sac
	An external pouch containing nutrients for the growing alevin. When the yolk sac is used up, the alevin is said to be "buttoned-up" and enters the fry stage.
zooplankton
	Animal component of the plankton that feed on phytoplankton and other zooplankton (primary consumers). Compare phytoplankton.
zygote
	A fertilized egg, or the diploid cell that results from the joining of two haploid gametes (sperm and egg) during sexual reproduction, that will cleave to form an embryo. See also fertilization and gamete.