So they're rerunning the Crystalline Entity special event for the next three weeks. It's similar to the last one in that every time you run Crystalline Catastrophe regular or elite, you get a crystal shard that you can use for an event reputation project. When you've contributed 14, you get the big reward of 50,000 dilithium, 500 fleet marks, 250 marks of your choice, and a very rare gravimetric doff named in homage of a certain CE-killing old lady from TNG. You still also get the standard rewards for completing the mission, those being 40/60 (standard/elite) marks of your choice, or 50/80 during bonus time, plus 5 fleet marks, 480 dilithium, and a random piece of space equipment.
The mission is changed up a little, and the Tholians will throw a ridiculous amount of Mirror Universe ships around the map, but it's nothing outrageous, and on normal it can still be completed in under 8 minutes with a half-competent PUG.
The fleet is in desperate need of resources, so if you can just run the event once on each of your alts each day 14 times, that would be a huge infusion of materiel in the end.