mitobox why am i vulnerable? how does the lack of oxygen affect me?
I based the effect the event has on each species by how evolved they are in terms of obtaining (gills, airsac) and distributing (circulatory passages) oxygen, since sustaining colonies/bodies becomes an issue. Immobile autotrophs would probably be fine, but no one here's evolved to be sessile, so oxygen consumption's going to be fairly high.
Tell you what; since you have phototropic dormancy (reducing oxygen consumption at night), I won't bump you below endangered unless you get a bad roll on something respiratory/circulatory.