Lolita has lost her ability to forage and catch live fish. Pursuit of prey is a full time job for wild killer whales and often requires complex cooperative "pack hunting" techniques.
Only once has any marine park allowed a scientific investigation of the theory that a long term captive would lose its ability to catch live fish. Two researchers (Newman and Markowitz, 1993) released live coho salmon with two orcas in a tank at Marine World Africa USA. The two orcas, captive for 24 and 13 years, echolocated on the fish, then caught and ate them.
Keiko has also demonstrated his ability to catch live fish. According to the Seattle Times (May 16, 1998):
Keiko the celebrity killer whale is gulping down 10-pound steelhead these days as if they were guppies...They started by feeding him dead fresh fish, then advanced to stunned fish that didn't swim much. Now, a couple of months into training, Keiko is chasing live steelhead and slurping them down...During a recent live-fish training session, Keiko tracked four steelhead to their doom without delay, swallowing them head first. He eats about half his diet now in live fish.
Lolita was six years old when she was captured. For at least five of those years she was chasing and catching her own fish, and without doubt she was engaging in complex, cooperative "pack hunting" techniques. There would be no way to test her ability to resume her role in such activities prior to releasing her to rejoin her family, but there is no particular reason to believe she would have forgotten how. Seaquarium staff have claimed that Lolita was once afraid of a fish in her tank, but introducing an Atlantic spiney rockfish to her tank is not a meaningful test of her foraging abilities.
Empirical studies and deductive reasoning lead to the conclusion that Lolita is fully capable of rapidly regaining and practicing the skill of catching and eating live fish, individually and cooperatively, with just a little practice.
Orcas, as members of the Delphinidae family that includes all dolphins, are known to share food with young or injured family members. It is reasonable to speculate that if Lolita should have difficulty obtaining sufficient fish in the days or weeks after her reunification with her family, other family members might assist her while she regained the needed skills.