To use the LBSPR Application you will need: 1) length composition data from your fishery (either raw measurements or counts), and 2) estimates of the life history parameters. The following paragraphs outline the steps to use the LBSPR Application. Each heading refers to a tab on the menu.

Upload Data

The first step is to upload a CSV (comma separated variable) file containing length data. The file must be in CSV format and contain only numeric values except for the header row which can contain labels. Multiple years of data should be placed in seperate columns.

Length frequency data must have the midpoints of the length classes (the length bins) in the first column, and numeric values for all counts (i.e., all columns are the same length). Length measurements should be raw numbers, each column representing a different year.

A number of example data files have been included. Download the CSV files to see the contents of these files

Fit Model

Enter the life history parameters for your species, and check that the length frequency distribution looks correct. If everything is correct, run the LBSPR model.

Use the example life history parameters for the example data files

Examine Results

The estimated parameters of the LBSPR model in tabular and graphical format. All figures can be downloaded. The estimated parameters can be downloaded in CSV format.

Upload a Length Data File


  1. Upload a CSV data file or select an example data set from the menu on the lower left
  2. Check that the details to ensure that the data has been read in correctly. The length data must be numeric values.

Enter Life History Parameters

The steps to fit the LBSPR model to the data are as follows:

  1. Enter the life history parameters for the species. Use the example parameters for the 'Example Data' from the 'Upload Data' tab. The Species name input is only used for downloads and plots. The model and parameters are not influenced by the Species name.
  2. Click 'Plot Data' and check that everything looks right
  3. If you're happy with everything, click 'Fit Model' to fit the LBSPR model to your data
  4. Visually inspect the fit. Has the model fitted the data? Remember: a good fit doesn't imply a good estimate, a terrible fit means something is wrong!
  5. Does the estimated selectivity curve make sense?
  6. If you are happy with everything, go to the 'Examine Results' tab

LBSPR Results