# 4.12. Marine Protected Areas (MPAs)¶

The user can defined as many MPA as he wishes. Here is how an MPA is defined in the configuration file:

mpa.file.mpa0 = maps/mpa0.csv
mpa.start.year.mpa0 = 10
mpa.end.year.mpa0 = 15


The map is a CSV file similar to the movement maps. The CSV file has the same number of lines and columns as the OSMOSE grid. Land is always indicated with -99, no MPA with 0 and MPA with 1. Start year and end year parameters define the time span when the MPA is enabled.

The MPA are handled within the Fishing process. Every time there is a new MPA to be activated or deactivated, Osmose updates the correction factor that will be applied to the fishing mortality rates in order to take into account the uniform redistribution of the fishing effort outside the MPAs.