How long do you think Atlanteans have for a natural life?
Being a super advanced society I think that it would be reasonable to assume that they have developed a ways to expand their lives. Though of course even pre 52, Aquaman's ancestor Kordax was centuries, if not thousands of years old, since his name has passed into legend and superstition. I would not be averse to believing Atlanteans are still fit and moving when humans are falling into piles of dust.
Theories and speculations are welcome. No need to strain for concrete advice.