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Larval Mortality Model


  1. Open Excel
  2. Click the Tools Menu
  3. Highlight the Macro sub menu
  4. Select Security... from the macro sub menu
  5. Select Medium
  6. Click the OK button
  7. Close Excel


  1. Click on the following link: "Larval Mortality Model"
  2. Save this file to your desktop
  3. Double click the file
  4. Choose to Enable Macros

Running the Model:
To start: The model is initially set to run for 30 days, with 200 larvae hatching into the plankton each day. The daily mortality rate is initially set at 0.23 per day, and is constant. Some larvae become competent to metamorphose at a shell length of 850 µm, and all larvae will metamorphose by the time they reach 1100 µm.

Variables to explore:

  • Number of days in the simulation
  • Number of larvae hatching each day
  • Daily probability of predation
  • Whether or not the probability of predation increases or decreases or remains
    constant as larvae get larger ; adjust coefficient B to alter predation rate with
    larval size
  • Size at which larvae become competent to metamorphose
  • Mean larval growth rate and amount of variation about the mean

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