opt_trophy: Optimum Trophy Size Limits for Recreational Fisheries

In fishmethods: Fishery Science Methods and Models

Optimum Trophy Size Limits for Recreational Fisheries

Description

Calculates optimum trophy catch over a range of F values and finds Fmax for a cohort given age-at-first recruitment, age-at-first-entry, and age at which fish are considered trophy size following Jensen (1981).

Usage

opt_trophy(M = NULL, N = 1000, recage = NULL, entage = NULL,
 trage = NULL, stF = 0, endF = 2, intF = 0.05)

Arguments

M	natural mortality
N	cohort size
recage	age-at-first recruitment
entage	age-at-entry into the fishery
trage	age of fish considered trophy size
stF	starting F of range to explore
endF	ending F of range to explore
intF	increment of F

Details

Calculations follow equations given in Jensen (1981).

Value

Catch	dataframe containing range of Fs and associated total catch and trophy catch of designated cohort size
Fmax	F at which trophy catch is maximum

Author(s)

Gary A. Nelson, Massachusetts Division of Marine Fisheries [e-mail]

References

Jense, A. L. 1981. Optimum size limits for trout fisheries. Can. J. Fish. Aquat. Sci. 38: 657-661.

See Also

opt_slot

Examples

# Example from Jensen (1981) page 659
opt_trophy(M=0.70,N=1000,recage=1,entage=1,trage=4)

fishmethods documentation built on April 27, 2023, 9:10 a.m.