The former university lecturer was heavily involved in project studies. Schirmer not only advised and assisted with nature conservation and compensation measures in Bremen and regional waters, but was also involved with Robin Wood and the BUND (Friends of the Earth Germany), among others. Since 2004, Schirmer has been working for the common good of Bremen's citizens in dike and flood protection as dike captain of the Bremen Dike Association on the right bank of the Weser. He is now in his fourth term of office.