20-Year Prospect
As diets have diversified and access to food in the Western world has gotten so abundant that we throw a lot of it away, fishing as a career has been on a downward slide for much of the last century. The next twenty years aren't looking much better.
From an increase in both price and imports of sea food, to the new big boys in town called "fish farms," to fishing limits imposed by the Federal government, life is not going to get any easier for the professional fisherperson (source). That may be why the career is expected to decline by as much as 6%. There may be plenty of fish in the sea, but the jobs available to catch them are drying up a bit.
If you have a love of fish, maybe you should look into fish farming and do your actual fishing on the weekends.