fishing mortality

fishing mortality
deaths or removal of fish from a population due to fishing. Usually expressed as the annual mortality, the percentage of fish dying in one year, or the instantaneous rate F, the percentage of fish dying at one time. F can range from 0 for no fishing to very high values such as 1.5 or 2, where 1.5 or 2 times as many fish have been caught as were present at the beginning of the fishing season (this is only possible with short-lived, fast growing species such as anchovies). Most mortality ends up in the catch but some fish are discarded and others are killed but not caught. Limiting the catch is used by fishery managers to control fishing mortality

Dictionary of ichthyology. 2009.

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  • fishing mortality — A mathematical expression of the rate of deaths of fish due to fishing. Fishing mortality is often expressed as a rate that indicates the percentage of the population caught in a year; e.g. a fishing mortality rate of 0.2 implies that… …   Fisheries — dictionary

  • fishing mortality rate — the fraction of an initial stock which would be caught during the year (or season) if no other causes of mortality operated. Usually expressed as an instantaneous rate (the percentage of fish dying at any one time) and can reach 2.0 or higher.… …   Dictionary of ichthyology

  • fishing mortality — Deaths in a fish stock caused by fishing …   Fisheries — dictionary

  • fishing mortality — Deaths in a fish stock caused by fishing …   Fisheries — dictionary

  • instantaneous rate of fishing mortality — used to describe the decrease in numbers of fish over time when fishing and natural mortality act concurrently (Nt = No * e^ Zt , where No is the initial number and Nt is the number of the remaining fish at the end of time t. Z is the… …   Dictionary of ichthyology

  • instantaneous rate of fishing mortality — When fishing and natural mortality act concurrently, F is equal to the instantaneous total mortality rate, multiplied by the ratio of fishing deaths to all deaths. Also called: rate of fishing; instantaneous rate of fishing; force of fishing… …   Fisheries — dictionary

  • instantaneous rate of fishing mortality — When fishing and natural mortality act concurrently, F is equal to the instantaneous total mortality rate, multiplied by the ratio of fishing deaths to all deaths. Also called: rate of fishing; instantaneous rate of fishing; force of fishing… …   Fisheries — dictionary

  • seasonal fishing mortality rate — conditional fishing mortality rate (the fraction of an initial stock which would be caught during the year (or season) if no other causes of mortality operated (Ricker, 1975). Also called annual mortality rate. Abbreviated as m) …   Dictionary of ichthyology

  • conditional fishing mortality rate — The fraction of an initial stock which would be caught during the year (or season) if no other causes of mortality operated. (Also called fishing mortality rate) …   Fisheries — dictionary

  • conditional fishing mortality rate — The fraction of an initial stock which would be caught during the year (or season) if no other causes of mortality operated. (Also called fishing mortality rate) …   Fisheries — dictionary

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