Fisheries management terms explained

[DarkSkies]

An easier breakdown of some of the terms, courtesy of Finchaser and the JCAA.





Acronyms, Abbreviations & Technical Terms Used in Fisheries Management Documents EEZ= Exclusive Economic Zone = Federal water from 3 to 200 nautical miles offshore. Fisheries in the EEZ are generally under federal Control

M = Natural mortality (M) -The instantaneous rate at which fish die from all causes other than harvest. This rate has traditionally included unmeasured bycatch mortality, but as research has documented bycatch, it is increasingly included in "F". Usually "M" is an assumption or estimate from maximum age data or the value used for other species with a similar life history strategy. Natural mortality can rarely be measured directly.

MRFSS = Marine Recreational Fisheries Statistics Survey

MSP = Maximum spawning potential = The estimated female spawning stock biomass or egg production in the absence of fishing. A percentage of this value (% MSP) can be used as a measure of the health of a stock.

MSY = Maximum sustainable yield = The largest catch, on average, which can be taken from a stock over time under existing environmental conditions without affecting the reproductive capacity of the stock.

MT = Metric Ton = 2,204.6 pounds

Recruit = An individual fish which has entered a defined group through growth,spawning, or migration, such as those fish above minimum legal size ( fishable stock) or which are sexually mature ( spawning stock).

Recruitment = A measure of weight or number of fish which enter a defined portion of a stock, such as fishable stock or the spawning stock.

SPR = Spawning potential ratio = SPR compares the spawning ability of a stock in the fished condition to the stock’s spawning ability in the unfished condition

SSB = Spawning stock biomass = total weight of fish which are sexually mature; generally pertaining only to females

TAC = Total allowable catch

Threshold = that point where the fishery is regarded as overfished

Target Values = that value or below which allows the fishery to be self sustaining

Biomass = The total weight of a stock of fish or of a defined subunit of a stock, such as spawning females (SSB)

Bycatch = That portion of a catch taken incidentally to the targeted catch because of non-selectivity of fishing gear to either species or size differences. Some by catch may be retained, but most is usually discarded

CPUE = C/E = The catch taken by a given amount of fishing gear during a given period of time. Over time, CPUE data often provides an indication of trends in abundance in a fish stock

Coastal Pelagic = Fish that migrate along the coast, generally near shore, and live in the water column rather than in association with the bottom.

Demersal = Refers to organisms which live at or near the bottom, but not in (Benthic) the bottom

Estuary = A coastal area landward of the ocean beach where freshwater and saltwater mix. Estuaries are among the most biologically productive and environmentally sensitive habitats.

ITQ = Individual transferable quota + A form of controlled access in which individual persons or vessels receive a property right to a share or specific allocation of the total expected harvest of fish which they can buy, sell, lease, etc.

Mortality rate = the rate at which fish die. Mortality can be expressed as annual percentages or instantaneous rates (the fraction of the stock which dies within each small amount of time). Fishery scientists utilize several different types of mortality to evaluate status of fish stocks, and some serve as biological reference points (Instantaneous rates are used in most stock assessments)

A = Annual mortality = the percentage of a fish stock which dies from all causes during a year.

Fishing mortality (F) = A measurement of the rate of removal of fish from a population by fishing. Fishing mortality can be reported as either annual or instantaneous. Annual mortality is the percentage of fish dying in one year. Instantaneous is that percentage of fish dying at ny one time. The acceptable rates of fishing mortality may vary from species to species. </SPAN>There are several kinds of fishing mortality rates; some of the more common include the following:

F max = The rate of fishing mortality which maximizes the weight taken from a single cohort* over its entire life. (* a group of fish spawned during a given period, usually in a single year)

F msy = The rate of fishing mortality, which maximizes the weight of the harvest within a year.

F 0,1 = The rate of fishing mortality at which an increase in catch for a given increase in effort is only 10% of what it would be from an unfished stock.

Z = Total instantaneous mortality = The sum of fishing F and natural mortality M



http://www.jcaa.org/jcnl0912/Mainpage.htm

[DarkSkies]

This is a key issue that IMO will sink many of us anglers when we're not paying attention. Fin has been harping on this, and I'm beginning to see he's dead on. They will, and have, used these slight variations to close a fishery down without justification.

Remember these terms, people, you'll be hearing them a lot in the future.

[DarkSkies]

ACRONYMS AND GLOSSARY OF COMMONLY USED TERMS

http://www.asmfc.org/commissionerMan...20Combined.pdf

[DarkSkies]

It's an important management term used by fisheries managers when deciding how best to approach a coming season.

One example of how this is used: larger minumums with longer season, or smaller minumum sizes with a longer season?


It goes into excrutiatingly painful detail here:

http://www.andrewloftus.com/reports/conseq.pdf