What is nominal Cpue?

Raw cpue, also called nominal cpue, is simply the total catch divided by the sum of an observable measure of effort associated with the catch, e.g. total number of hooks for longline fisheries. Cpue is usually calculated for a defined time period (e.g. year), but can also be restricted by spatial or other strata.

What is catch rate in fishing?

To estimate total recreational catch, we expand catch rate—or the number of fish caught per fishing trip—by effort—or the total number of fishing trips taken.

How do I know my CPUE?

CPUE is calculated by dividing the catch of each fishing trip by the number of hours fished during that trip. This gives CPUE in units of kilograms per hour. The median for every year is then calculated in order to remove outliers – some fishers are much more efficient than others.

What does CPUE stand for?

Catch Per Unit Effort
Definition of Catch Per Unit Effort (CPUE): Catch-Per-Unit-Effort (CPUE) – also called catch rate – is frequently the single most useful index for long-term monitoring of a fishery. Declines in CPUE may mean that the fish population cannot support the level of harvesting.

What is the unit of catchability in fishing?

So the unit of catchability is fish caught per fish available per effort unit and per time unit. Catchability is also called gear efficiency (Hilborn and Walters, 1992) or sometimes fishing power, and is strongly related to gear selectivity (defined below) because it is species and size dependent.

How is catchability related to true population size?

Catchability ( q) is defined (see equation 3) as the relationship between the catch rate ( CpUE) and the true population size ( B ). So the unit of catchability is fish caught per fish available per effort unit and per time unit.

What are the aspects of the catchability coefficient?

It involves various aspects of the fishery, such as individual and population biology, characteristics of the fishing gear, amount of fishing, fishing strategies, and environmental fluctuation, among others.The concept is proposed of an integrated model of the catchability coefficient, which incorporates various of the aspects mentioned above.

How are catch and abundance related in fisheries theory?

Furthermore, the most commonly used contemporary method of estimating the relative abundance of an exploited fish stock is by using the catch per unit effort ( C/f) as an index of abundance. The basic assumption in fisheries theory is that catch ( C) and stock abundance, or standing biomass ( B) are related by