...where one might unfortunately catch their skate blade in? Having lived in the southwest part of the country most of my life where there has been neither cause nor occasion for me to experience such a word. How would you caution someone to "lookout for the potholes in the ice!"
I think ruts should work.
Quoting a patent related to ice-skating rink repairs:
The term “rut” refers to local, concave imperfections in the surface of an ice rink, including grooves, nicks, cracks, and gouges. (Ruts are typically caused by ice skate blades, falls, and hockey sticks.)
I found a Trip Advisor review of a visit to the Victoria Park Oval in Edmonton, Canada which starts by saying
About an inch of shaved ice covered both the freezeway and oval, so difficult to see cracks and pits in ice. Thankfully there were not many at the time.
This review was from January 2016 by a lady calling herself Slik50 and is about the ninth one on the site so you have to scroll down a way. However Slik50 does seem to be an experienced skater and refers to pits in the ice as though her readers would know what she meant. I suspect that this term is used for that kind of damage quite widely, at least in Canada.
The best way to find out what this sort of damage is called in your area is to ask local skaters, but I think that they might call it "pits".