The 37-year old man is reported to have targeted the Lagoa area, setting a number of fires between the beaches of Marinha and Benagil on 4 August.
A total of 12 fires were dealt with that day, consuming a 10,000 square metres of scrubland in the process and also destroying wooden structures found at the beaches.
The Lagoa Fire Department said that the fires were kept under control thanks to the swift action by fire-fighters.