Stock-Recruitment

- Read Maceina and Pereira (2007) Sections 4.1-4.4 (complete chapter is here) and consider the items below.
- What is the distribution of recruitment rates in many marine systems? Describe what this distribution looks like and what it means for recruitment rates?
- What (generically) is a primary cause of recruitment variability?
- What is recruitment overfishing?
- How (generally) is recruitment defined for a particular stock? Who decides on this definition?
- How long does it take to collect useful stock and recruitment data?
- What is CV?
- What are the two primary stock-recruitment (SR) functions (i.e., both are named after prominent fisheries scientists)?
- In both SR functions, what does α and β represent?
- What is the equation for the Beverton-Holt SR function? Describe the shape of this curve? What stock/spawner abundance results in the highest level of recruitment according to this model?
- What is the equation for the Ricker SR function? Describe the shape of this curve? What stock/spawner abundance results in the highest level of recruitment according to this model?
- What is overcompensation? What are example behaviors or population dynamics that may lead to overcompensation?
- What type of statistical technique is used to fit a SR function to data? What type of “error structure” should be used with this technique?

- Read Section 13.1 in
*Introductory Fisheries Analyses with R*and consider the items below.- What are two characteristics of most stock-recruitment (SR) data sets?
- What are the two primary stock-recruitment (SR) functions (i.e., both are named after prominent fisheries scientists)?
- In both SR functions, what does α and β represent?
- What is the equation for the Beverton-Holt SR function? Describe the shape of this curve? What stock/spawner abundance results in the highest level of recruitment according to this model?
- What is the equation for the Ricker SR function? Describe the shape of this curve? What stock/spawner abundance results in the highest level of recruitment according to this model?
- What R function is used to find starting values for fitting a SR function? What arguments does it need?
- What R function is used for fitting a nonlinear regression? What arguments does it need for fitting a SR model?
- What function extracts the parameters estimates from the results above?
- What function extracts confidence intervals for the parameters from the results above?
- How can one determine if the density-dependent parameter in a SR function is statistically significant?