Sure it's a crack? Absolutely sure? If it is then it may enlarge as the crack spreads. The next step would then depend on how much you love your bike and it's aesthetics. I cracked my carbon frame about 15 years ago (I know, I know. My bike is past it's sell by date according to everyone on here) but I fixed the crack (not pretty) and it's as good now as when I fixed it. I still ride it, have raced on it (mass start, not TT) and it's my summer bike of choice. IF (massive if) it's cracked then source a carbon repair kit on the net. Follow the instructions and it'll last until you really do some damage. It sure as hell won't look pretty but if that's an issue then have it fixed with the pros at pro money. Compared to the damage I did your crack is minimal and more probably a scratch. Nice looking bike though.