|
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. 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
|
JCAA
Newsletter