Using a sample of dwarf irregular galaxies selected from the ALFALFA blind HI-survey and observed using the VIMOS IFU , we investigate the relationship between H \alpha emission and Balmer optical depth ( \tau _ { \text { b } } ) .
We find a positive correlation between H \alpha luminosity surface density and Balmer optical depth in 8 of 11 at \geq 0.8 \sigma significance ( 6 of 11 at \geq 1.0 \sigma ) galaxies .
Our spaxels have physical scales ranging from 30 to 80 pc , demonstrating that the correlation between these two variables continues to hold down to spatial scales as low as 30 pc .
Using the Spearman ’ s rank correlation coefficient to test for correlation between \Sigma _ { \text { H } \alpha } and \tau _ { \text { b } } in all the galaxies combined , we find \rho = 0.39 , indicating a positive correlation at 4 \sigma significance .
Our low stellar-mass galaxy results are in agreement with observations of emission line regions in larger spiral galaxies , indicating that this relationship is independent of the size of the galaxy hosting the emission line region .
The positive correlation between H \alpha luminosity and Balmer optical depth within spaxels is consistent with the hypothesis that young star-forming regions are surrounded by dusty birth-clouds .

Key words : galaxies : general - galaxies : dwarf - galaxies : irregular - galaxies : ISM