Adaptability: The capability of an organism to adapt to changing or future environmental conditions, the capability depends on adequate genetic variation remaining in the population.

Adaptation: A genetically determined trait that increases the relative fitness of an individual in its environment (an adaptation refers to a current trait and results from the integration of past genetic and environmental interactions).

Age-class: The brood year (year the fish was born) or the salt-water entry year that defines a cohort of fish (same as year class).

B.

Blood water: An untreated mixture of blood and fish debris from harvested or slaughtered fish.

Biomagnification: The increase of organisms through biological processes.

C.

Causative (etiological) agent: The cause of a clinically diagnosed disease, which sometimes has the same name as the disease itself.

Chemotherapeutants: Chemical compounds used to treat and control diseases (e.g. antibiotics, pesticides).

(Fish) culture: Cultivation of fish from broodstock. In salmonid enhancement and ocean ranching, the fish are released from the hatchery. In salmon farming, the fish remain in captivity through their whole life cycle.

D.

Disease: A condition of the body, or some part or organ of the body, in which its functions are disturbed or deranged. In fish, indicated by discoloration, mortality, behavioural changes (fish do not swim, or remain near surface), poor growth, changes in the quality of the flesh.

E.

Enzootic: Disease endemic to a particular region – naturally occurring, indigenous.

Epizootic: Disease temporarily present in a population of animals, attacking many animals in a population simultaneously (like epidemic) – also called an "outbreak."

Etiology: The study of the cause of a disease.

Evolutionarily significant unit: A set of populations that is morphologically and genetically distinct from other similar populations, or a set of populations with a distinct evolutionary history.

F.

Fallowing: The process of leaving an aquaculture site unused for a period of time, in order to facilitate seabed recovery and rehabilitation (cf. abandonment).

Feral: Animals belonging to or forming a wild population ultimately descended from individuals which escaped from captivity or domestication.

Fitness: The relative ability of a genotype (an individual) in its environment to successfully contribute offspring to the next generation. In salmon, fitness is frequently equated to the number of progeny produced per spawn.

Founder Effect: In genetic terms, the creation of a new population based on a very small number of parents. These "founders" may be a very limited portion of the genetic material in the source population. A "founder" event may have a similar effect but is caused within a population by a severe crash in population size.

G.

Gravid: Female adult lice capable of reproduction.

H.

Hybrid vigor: An increase in the fitness in a population due to the masking of recessive deleterious genes due to the mating of unrelated animals, usually from different populations.

I.

Immunocompetent: A state in an organism describing its ability to mount an immune response.

Inbreeding depression: A loss of fitness in a population due to increasing relatedness of individuals within the population, and through the expression of deleterious recessive genes due to mating of related individuals.

Inbreeding: The mating together of individuals that are related to each other by ancestry; increased levels of inbreeding results in a loss of genetic variation within the population.

Introgression: Gene flow between populations that hybridize, i.e., the introduction of genes from a non-local population via the inter-mating of the two populations. The extent of gene flow depends on hybridization effects. Enhanced productivity may increase the rate of exchange (e.g. hybrid vigor), but reduced productivity over time (e.g. outbreeding depression) would reduce it.

L.

Morbidity: The prevalence and severity of impacts of disease.

Morts: … or mortalities: deaths, specifically, farmed fish that have died prior to harvest.

Motile: Lice that are beyond the infective stage.

O.

Outbreeding depression: The loss of fitness in a population due to "swamping" the locally adapted genes by straying from a different population, and/or the breakdown of biochemical or physiological capabilities due to the mixing of populations with different genetic backgrounds.

P.

Pathogen: Agent of disease/infectious agent. Those of concern here are viruses, bacteria and parasites. While the term is often used to include only the first two of these, usage in this report includes parasites.

Pathogenicity: Whether or not the normal functioning of the fish is affected and the chances of survival of the fish are reduced; the ability to cause a disease.

Plasmid: A linear or circular molecule of DNA which can replicate independently from the chromosomal DNA of an organism. If a proportion of DNA is added to that of a plasmid, the sequence can be added to a cell where it can replicate and alter the host genome.

Population: Group of individuals of one species occupying a defined area and sharing a common gene pool. For wild salmon, a localized spawning group of fish that is largely isolated from other such groups.

Practical recovery time or "PRT": The interval from cessation of aquaculture operations to the time when diversity cannot be distinguished reliably from the reference value.

R.

Run/stock: Genetically similar group of fish having a shared source and destination place or time. In the wild, the group of fish that return to the same geographic area (natal watershed), or that return at the same time period. On a salmon farm, the group of fish at a farm site.

S.

Salmonid: A category of fish that includes salmon, steelhead and trout.

Smolt/Smoltification: Life stage/process that is the transition from freshwater parr to seaward migrants.

Stress: A response to a situation that is beyond the scope of what the animal normally encounters, although stressors may be frequent and numerous. Health may be looked at as the capacity to deal with stress without succumbing to disease.

V.

Virulence: The ability of a microorganism to cause disease.

Y.

Year class: The brood year (year the fish was born) or the salt-water entry year that defines a cohort of fish.