Salmon escapement is the amount of a salmon population that does not get caught by commercial or recreational

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...

and return to their freshwater spawning habitat. Estimates of these amount are calculated with statistical analysis using data collected during that particular run season. These estimations help produce

fishing quota Catch share is a fishery management system that allocates a secure privilege to harvest a specific area or percentage of a fishery's total catch to individuals, communities, or associations. Examples of catch shares are individual transferable quot ...

s for the return year of the juveniles born for that years run, or can be used to determine the health of a salmon stock. Estimating escapement for salmon can be done several ways: The most commonly used method is the

area-under-the-curve In the field of pharmacokinetics, the area under the curve (AUC) is the definite integral of the concentration of a drug in blood plasma as a function of time (this can be done using liquid chromatography–mass spectrometry). In practice, the drug ...

model, and other methods include the change-in-ratio method, carcass-counting surveys, and weir-count surveys.

Escapement goals

Biological Escapement Goals (BEGs) are the number of returning salmon that would provide the largest possible amount of take while ensuring that enough salmon will successfully spawn, so that their offspring will replace the harvested amount in future runs. A BEG model is applied when a fishery harvests salmon in a manner that will allow managers to determine the desired spawning destination for that population of salmon. Sustainable Escapement Goals (SEGs) are the amount of escapement needed, specified by an index or escapement estimate; that is known to provide a

sustainable yield The sustainable yield of natural capital is the ecological yield that can be extracted without reducing the base of capital itself, i.e. the surplus required to maintain ecosystem services at the same or increasing level over time. The term only ...

over a period of up to 10 years. The SEG is applied when there is not enough catch data for that stock such as the

Alaska salmon fishery The Alaska salmon fishery is a managed fishery that supports the annual harvest of five species of wild Pacific Salmon for commercial fishing, sport fishing, subsistence by Alaska Native communities, and personal use by local residents. The salmo ...

which harvests salmon in a non-terminal area and the desired spawning destination for that salmon population is unknown. Optimal Escapement Goals (OEGs) consider biological and allocative influences and it may produce a diffident estimate then SEG or BEG goals. This goal is used when a managing groups wants to reallocate quotas, and essentially determines who may fish and where they fish for certain salmon populations. The OEG will allow sustainability and will be conveyed as a range with the lowest possible escapement level set to be above the estimate for Sustainable escapement.

References

*http://www2.humboldt.edu/cuca/documents/theses/wrightthesis.pd{{dead link, date=May 2018 , bot=InternetArchiveBot , fix-attempted=yes Fisheries science

Escapement goals

See also

References