In fisheries and

conservation biology Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an ...

, the catch per unit effort (CPUE) is an

indirect measure Indirect, the opposite of direct, may refer to: *Indirect approach, a battle strategy *Indirect DNA damage, caused by UV-photons *Indirect agonist or indirect-acting agonist, a substance that enhances the release or action of an endogenous neurotra ...

of the abundance of a target species. Changes in the catch per unit effort are inferred to signify changes to the target species' true abundance. A decreasing CPUE indicates

overexploitation Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term ap ...

, while an unchanging CPUE indicates sustainable harvesting. CPUE has a number of advantages over other methods of measuring abundance. It does not interfere with routine harvesting operations, and data are easily collected. The data are also easy to

analyse Analyse or analyze may refer to: *Analyse, to do or make an analysis (disambiguation) * "Analyse" (Thom Yorke song), a song by Thom Yorke from the 2006 album ''The Eraser'' * "Analyse" (The Cranberries song), a song by The Cranberries from the 2 ...

, even for non-specialists, in contrast to methods based on transects. This means that decisions about

stock management Field inventory management commonly known as inventory management is the function of understanding the stock mix of a company and the different demands on that stock. The demands are influenced by both external and internal factors and are balan ...

can also be made by the people doing the harvesting. The

best practice A best practice is a method or technique that has been generally accepted as superior to other known alternatives because it often produces results that are superior to those achieved by other means or because it has become a standard way of doing ...

is to standardise the effort employed (''e.g.'' number of traps or duration of searching), which controls for the reduction in catch size that often results from subsequent efforts. Although CPUE is a relative measure of abundance, it can be used to estimate absolute abundances. The main difficulty when using measures of CPUE is to define the unit of effort.

References

{{fishery science topics, expanded=science Conservation biology Fisheries science

See also

References