Hα image of M83 taken with IMACS on the Magellan II telescope in 2009 (for details, see Blair et al. 2012). All of the SNR candidates from Blair et al. (2012) are marked with blue circles; additional (non-duplicate) candidates from Dopita et al. (2010) by green circles. The red squares indicate objects for which we obtained GMOS spectra (listed in Table 2). Note that the objects with spectra are well distributed around the galaxy, with the exception of the very outermost regions. We chose not to target those areas because the sparse population would have made less efficient use of the GMOS capabilities. The overall field shown is 9.′3 square, oriented north up, east left.