StdEffort: Standardization of Fishing Effort (StdEffort)

In FESta: Fishing Effort Standardization

Standardization of Fishing Effort (StdEffort)

Description

This package provides a function named StdEffort for standardisation of fishing effort expended by various fishing gears in order to obtain the Catch Per Unit Effort (CPUE) for a particular fish species using the time series of total catch (landings) by each fishing gear, catch (landings) of a particular species (for which the CPUE is required) by each gear, and total effort expended by each gear. See the example dataset StdEffort_dataset.

Usage

StdEffort(sp_catch, tot_catch, effort, meg)

Arguments

sp_catch	Time series of catch/landings of a particular species (for which the CPUE is required) by each gear. First column should be year.
tot_catch	Time series of total catch/landings by each fishing gear. First column should be year.
effort	Time series of total effort expended by each gear. First column should be year.
meg	Choose most efficient gear by providing the corresponding gear name (String value). (for most efficient gear as standard unit).

Details

A method for estimating species-specific fishing effort in multi-gear fisheries where fishing gears differ in efficiency and catch composition. The procedure allocates fishing effort to the target species using catch proportions and gear-specific weighting factors, and expresses effort in terms of a common standard gear unit. The standardized effort is then used to compute a CPUE index suitable for stock assessment, abundance monitoring, and fisheries management analyses.

Marine fisheries governance and management practices are very essential to ensure the sustainability of marine resources. A widely accepted resource management strategy towards this is to derive sustainable fish harvest levels based on the status of marine fish stock. Various fish stock assessment models that describe the biomass dynamics using time series data on fish catch and fishing effort are generally used for this purpose.

In the scenario of a complex multi-species marine fishery in which different species are caught by a number of fishing gears, and each gear harvests a number of species, it is difficult to obtain the fishing effort corresponding to each fish species. Since the capacity of the gears varies, the effort made to catch a resource cannot be considered as the sum of efforts expended by different fishing gears. This necessitates standardisation of fishing effort on a unit basis.

This function standardises fishing effort expended by various gears and obtains Catch Per Unit Effort (CPUE) for a particular fish species using time series data of total catch by each fishing gear, catch of a particular species, and total effort expended by each gear.

Value

The output includes a summary table containing Year, Total Catch, Nominal CPUE, and Standardized CPUE. In addition, two plots are produced: Nominal CPUE versus Total Catch and Standardized CPUE versus Total Catch.

Note

The standardised effort can be obtained by user chosen gear (for example, OBGN in hours) for that species.

References

Eldho Varghese, T. V. Sathianandan, J. Jayasankar, Somy Kuriakose, K. G. Mini and M. Muktha (2020). Bayesian State-space Implementation of Schaefer Production Model for Assessment of Stock Status for Multi-gear Fishery, Journal of the Indian Society of Agricultural Statistics, 74(1), 35–42.

Acknowledgements: The authors sincerely thank the Director, ICAR–Central Marine Fisheries Research Institute (ICAR-CMFRI), Kochi, for providing the necessary facilities and institutional support. The authors also gratefully acknowledge the support provided by the Indian Council of Agricultural Research (ICAR), Department of Agricultural Research and Education (DARE), Government of India, through the ICAR-National Fellow Project.

Examples

## Not run: 
library(FESta)
data("StdEffort_dataset")
result<-StdEffort(
  sp_catch  = StdEffort_dataset$sp_catch,
  tot_catch = StdEffort_dataset$tot_catch,
  effort    = StdEffort_dataset$effort,
  meg       = 'OBGN'
)
print(result)

## End(Not run)

FESta documentation built on Aug. 20, 2026, 5:10 p.m.