fishing mortality rate


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. May be expressed as an annual rate (the percentage of fish dying in one year). Doubling the effort will double the catch but eventually increased effort drives down the stock\'s biomass. Abbreviated as F. Also called conditional fishing mortality rate

Dictionary of ichthyology. 2009.

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  • 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

  • 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 or seasonal fishing mortality rate. Abbreviated as m or m …   Dictionary of ichthyology

  • mortality rate — 1) the rate at which the numbers in a population decrease with time due to various causes. The proportion of the total stock (in numbers) dying each year is the annual mortality rate. To facilitate calculations, mortality is expressed as an… …   Dictionary of ichthyology

  • 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 — 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… …   Dictionary of ichthyology

  • annual mortality rate — the ratio between the number of fish which die during a year from causes other than fishing and the number alive at the beginning of that year. Also called annual natural mortality rate, conditional natural mortality rate, seasonal natural… …   Dictionary of ichthyology

  • fishery mortality rate — a measure of how quickly fish are removed from a population. Fishing mortality rates greater than 1.0 are considered very high …   Dictionary of ichthyology

  • 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