Virtual population analysis (VPA) is a widery used model for
the analysis of fished populations. While there are many VPA techniques, they
vary in the way they use data and fit the model rather than in the form of the
model itself. This manual describes the common VPA model and the assumptions on
which it is based, together with descriptions of associated diagnostic
procedures and common reference points. More important, the manual describes the
numerical techniques that can be used to fit the model based on weighted
least-squares, which is the basis for the ADAPT approach. The techniques are
described so that they are readily implemented in a spreadsheet. General methods
and specific examples are given to enable readers to develop an approach
suitable for their own data and fisheries
