Weren't the crew already doomed before WAU

[cantremember]

I seem to remember notes mentioning other sites were running low on food too, empty fridges and cafetarias, although I should replay to be able to tell for certain.
Tau was stocked by Omicron, but the other sites weren't getting any new supplies from the mainland either.

The fish habitats outside Omicron are really small, and I didn't find any info that suggests they used them as food source. The habitats were probably already there from before the comet struck, when they didn't even had a need to farm fish. My impression is that the fish habitats had some scientific purpose, as there's a laboratory and some fish studies going on inside Omicron.

In any case, even with food, they still only had limited power (two decades or so)