Compute reference points (Umsy, Smsy, and Sgen) from Ricker stock-recruit function
based on Scheuerell (2016).
Usage
calc_Smsy_Ricker(loga, b)
calc_Umsy_Ricker(loga)
calc_Sgen_Ricker(loga, b)
Arguments
- loga
Numeric, alpha parameter (returns per spawner) in the Ricker function: \(R=S\exp(\log(a)-bS)\)
where S is the number of spawners and R is the return
- b
Numeric, beta parameter
Value
All three functions return a numeric
References
Scheuerell, M.D. 2016. An explicit solution for
calculating optimum spawning stock size from Ricker’s stock recruitment model. PeerJ 4:e1623. doi:10.7717/peerj.1623