Read this, Sections 11.2.4 in Ogle (2016) and re-read end of Section 6.3.2 (about assumptions) in Miranda and Bettolli (2006)] and answer the following questions.

  1. What are the assumptions of a catch curve model for estimating Z?
  2. What assumption about recruitment is made for a catch curve? Is this a realistic assumption? How do modest violations of this assumption affect the estimates of Z?
  3. How large of a sample is needed for a catch curve analysis?

Read Sections 11.4 in Ogle (2016) and answer the following questions.

  1. Define Z, F, M, and μ.
  2. What is the relationship between Z, F, and M?
  3. Explain what is meant by “meta-analysis to estimate M, F, or Z.”
  4. Check out this online tool that provides meta-analytic estimates of M.

Read Section 6.6 in Miranda and Bettolli (2006) and answer the following questions.

  1. Explain how the regression between Z and fishing effort can be used to estimate M. What are some problems with this method.
  2. Explain how the catch-curve methods of the last module could be used to estimate M.
  3. Explain how mark-recapture data can be used to estimate F (carefully explain what else must be know for this method to work).

Read Allen and Hightower (2010) Mortality (most of the complete chapter) and answer the following questions.

  1. Explain how mortality rate changes with age from hatch through late adulthood.
  2. What kind of management actions can be enacted to control F?
  3. Describe what abundance (y-axis) versus time (x-axis) would look like if one followed a cohort (i.e., year-class) of fish through time.
  4. Describe the difference between a discrete (Type I) and continuous (Type II) fishery.
  5. How is μ calculated in a continuous fishery?
  6. How is A computed from m and n in a continuous fishery? Why is the product of m and n included in this computation?

Read Sections 6.8-6.10 in Miranda and Bettolli (2006) and answer the following questions.

  1. How is “additive mortality” defined?
  2. How is “compensatory mortality” defined?
  3. What does “additive mortality” look like in a plot of A versus μ?
  4. What does “compensatory” look like in a plot of A versus μ?
  5. How might the realization that compensatory mortality exists and an understand of how it exists influence management decisions?
  6. What are management tools (i.e., regulations) commonly used to modify fishing mortality?
  7. What is the greatest difficulty in estimating mortality?