fishmethods (version 1.5-0)

opt_slot: Optimum Slot and Trophy Size Limits for Recreational Fisheries

Description

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

Usage

opt_slot(M = NULL, N = 1000, recage = NULL, entage = NULL,
 trage = NULL, slage = 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

slage

upper age of slot for legal fish

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

Value

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

Details

Calculations follow equations given in Jensen (1981).

References

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

See Also

opt_trophy

Examples

# Example from Jensen (1981) page 661
opt_slot(M=0.70,N=1000,recage=1,entage=1,slage=3,trage=4)