DAQ devices only measure electrical inputs. At this point you're needing equipment that can detect wavelengths like an OSA (Optical Spectrum Analyzer) which can be quite expensive if you don't already have one.
If your end goal is to read your FBGs, then I suggest the NI PXIe-4844 which will read in reflected wavelengths between 1510-1590 nm. It is much cheaper than a full blown OSA and is specifically designed to read FBGs (and one of the most accurate on the market). It can return to you the spectrum if you would like to do your own analysis, or you can have it do all the work for you by returning the detected peaks and converting the measured peak wavelengths back to engineering measurements like strain, temperature, water level, etc.
